Mailing List Archive

Hi, it seems improbable that your desktop PC would have only one HDD slot.
Could you post your exact model number please? :)
To give you some hope, I have had Linux installed on external hdd for daily
use for about two years. It is at least five years back, it was over USB
2.0 and worked quite well. I did some photo editing and retouching and it
was ok.
How big is your internal drive anyway? Isn't it possible to use around 30GB
for Gentoo system partition? Or do you just want to keep original hdd
intact?
Regards,
Peter
​

On Wed, Aug 28, 2013 at 12:24 PM, Henry W. Peters <hwpeters@jamadots.com> wrote:
> Hi,
>
> Hope this is a good list for my question/problem (please someone direct me
> to another list, if not).
>
> I purchased a HP Pavillion desktop, AMD64 computer on the premise that I
> could add an additional HD (verified by an HP "technician")... on which I
> plan to install Gentoo... I (finally) got the additional hard drive... but
> now it appears that you CANNOT add an additional internal HD... (no room, no
> slot, unless perhaps one does modifications, then (most likely, there goes
> the warantee?)).
>
> So my question is: will an external HD work (I do audio
> editing/recording/graphics) as a system/work space? & more importantly, will
> Gentoo install on such a HD (external, usb 3))
>
> Thanks much for any advice/help.
>
> Henry
>
>

Hi,
If you really need a new drive (i.e. - the one that came with your
machine is just too small, etc.) then I'd look at imaging the drive
that's currently installed, putting in a larger drive, partitioning
this larger drive to hold both Gentoo and what ever M$ OS you might be
using, and then just work to get both OS's working but keep the
current drive on the shelf as a backup. This way you could always go
back to what you have.

Just an idea.

Good luck,
Mark

On Wed, 28 Aug 2013 12:50:48 -0700 you corralled some electrons and wrote:

> On Wed, Aug 28, 2013 at 12:24 PM, Henry W. Peters <hwpeters@jamadots.com> wrote:
> > Hi,
> >
> > Hope this is a good list for my question/problem (please someone direct me
> > to another list, if not).
> >
> > I purchased a HP Pavillion desktop, AMD64 computer on the premise that I
> > could add an additional HD (verified by an HP "technician")... on which I
> > plan to install Gentoo... I (finally) got the additional hard drive... but
> > now it appears that you CANNOT add an additional internal HD... (no room, no
> > slot, unless perhaps one does modifications, then (most likely, there goes
> > the warantee?)).
> >
> > So my question is: will an external HD work (I do audio
> > editing/recording/graphics) as a system/work space? & more importantly, will
> > Gentoo install on such a HD (external, usb 3))
> >
> > Thanks much for any advice/help.
> >
> > Henry
> >
> >
>
> Hi,
> If you really need a new drive (i.e. - the one that came with your
> machine is just too small, etc.) then I'd look at imaging the drive
> that's currently installed, putting in a larger drive, partitioning
> this larger drive to hold both Gentoo and what ever M$ OS you might be
> using, and then just work to get both OS's working but keep the
> current drive on the shelf as a backup. This way you could always go
> back to what you have.
>
> Just an idea.
>
> Good luck,
> Mark
>

To the point of the original poster: I currently use a Lenovo W520 laptop.
I have a USB3 external hard drive that I mostly use for backup, but I have
occasionally edited some audio (small audio files using Audacity) directly
on the external drive. Again, it's not the OS drive, so temp files and such
are most likely stored on the internal drive, but I know that Audacity
operates in the directory in which the project is located, so it's still
doing a fair bit of I/O to that external drive.

Hope this helps!

~David

On 8/28/2013 3:46 PM, czernitko wrote:
> Hi, it seems improbable that your desktop PC would have only one HDD
> slot. Could you post your exact model number please? :)
> To give you some hope, I have had Linux installed on external hdd for
> daily use for about two years. It is at least five years back, it was
> over USB 2.0 and worked quite well. I did some photo editing and
> retouching and it was ok.
> How big is your internal drive anyway? Isn't it possible to use around
> 30GB for Gentoo system partition? Or do you just want to keep original
> hdd intact?
> Regards,
> Peter
> ​
> Hi,
> If you really need a new drive (i.e. - the one that came with your
> machine is just too small, etc.) then I'd look at imaging the drive
> that's currently installed, putting in a larger drive, partitioning
> this larger drive to hold both Gentoo and what ever M$ OS you might be
> using, and then just work to get both OS's working but keep the
> current drive on the shelf as a backup. This way you could always go
> back to what you have.
>
> Just an idea.
>
> Good luck,
> Mark
> To the point of the original poster: I currently use a Lenovo W520 laptop.
> I have a USB3 external hard drive that I mostly use for backup, but I have
> occasionally edited some audio (small audio files using Audacity) directly
> on the external drive. Again, it's not the OS drive, so temp files and such
> are most likely stored on the internal drive, but I know that Audacity
> operates in the directory in which the project is located, so it's still
> doing a fair bit of I/O to that external drive.
>
> Hope this helps!
>
> ~David

Thanks all for helpful suggestions!

First off, capacity of current internal drive is not really an issue
with me... it is 2 TB... I tried installing Gentoo on another (very much
older computer) a while ago & had problems installing Grub, with Gentoo,
as I was dual booting with windows (not to mention conflicts with xstart
& my old integrated SIS graphics card)... so my thinking is to install
Gentoo on a whole other HD... which seemed to work out on my old
computer (or perhaps it was simpler to do for a Gentoo novice, like myself).

& Peter, I'm with you... I have not seen a desktop computer that didn't
have at least one expansion bay (not that I've seen that many)... but
apparently this HP Pavillion 500-046 does not. & I really had to dig to
find out (the hard way).

Good to hear that some have had some measure of success with external
drives & Gentoo, rather sounds like I'll just have to try it...

I have done a little more research since my earlier post, & I see that
LaCie (& possibly others) make/sell an external drive that has usb 2 &
3/firewire 400 & 800/eSata (& there are, it seems, some extra Sata slots
on the mother board of this HP computer).

My plan, in fact, after a installation of Gentoo... would be to shrink
the 2 TB partition that is currently formatted in NTS... (Windows 8),
use the other partition formatted in ext 4 (i.e., Linux) data storage.

Henry
(who's trying hard to get away from windows, again (been using various
flavors of Linux for about five years)

On Wed, Aug 28, 2013 at 1:39 PM, Henry W. Peters <hwpeters@jamadots.com> wrote:
> On 8/28/2013 3:46 PM, czernitko wrote:
>>
>> Hi, it seems improbable that your desktop PC would have only one HDD slot.
>> Could you post your exact model number please? :)
>> To give you some hope, I have had Linux installed on external hdd for
>> daily use for about two years. It is at least five years back, it was over
>> USB 2.0 and worked quite well. I did some photo editing and retouching and
>> it was ok.
>> How big is your internal drive anyway? Isn't it possible to use around
>> 30GB for Gentoo system partition? Or do you just want to keep original hdd
>> intact?
>> Regards,
>> Peter
>>
>> Hi,
>> If you really need a new drive (i.e. - the one that came with your
>> machine is just too small, etc.) then I'd look at imaging the drive
>> that's currently installed, putting in a larger drive, partitioning
>> this larger drive to hold both Gentoo and what ever M$ OS you might be
>> using, and then just work to get both OS's working but keep the
>> current drive on the shelf as a backup. This way you could always go
>> back to what you have.
>>
>> Just an idea.
>>
>> Good luck,
>> Mark
>> To the point of the original poster: I currently use a Lenovo W520 laptop.
>> I have a USB3 external hard drive that I mostly use for backup, but I have
>> occasionally edited some audio (small audio files using Audacity) directly
>> on the external drive. Again, it's not the OS drive, so temp files and
>> such
>> are most likely stored on the internal drive, but I know that Audacity
>> operates in the directory in which the project is located, so it's still
>> doing a fair bit of I/O to that external drive.
>>
>> Hope this helps!
>>
>> ~David
>
>
> Thanks all for helpful suggestions!
>
> First off, capacity of current internal drive is not really an issue with
> me... it is 2 TB... I tried installing Gentoo on another (very much older
> computer) a while ago & had problems installing Grub, with Gentoo, as I was
> dual booting with windows (not to mention conflicts with xstart & my old
> integrated SIS graphics card)... so my thinking is to install Gentoo on a
> whole other HD... which seemed to work out on my old computer (or perhaps it
> was simpler to do for a Gentoo novice, like myself).
>
> & Peter, I'm with you... I have not seen a desktop computer that didn't have
> at least one expansion bay (not that I've seen that many)... but apparently
> this HP Pavillion 500-046 does not. & I really had to dig to find out (the
> hard way).
>
> Good to hear that some have had some measure of success with external drives
> & Gentoo, rather sounds like I'll just have to try it...
>
> I have done a little more research since my earlier post, & I see that LaCie
> (& possibly others) make/sell an external drive that has usb 2 & 3/firewire
> 400 & 800/eSata (& there are, it seems, some extra Sata slots on the mother
> board of this HP computer).
>
> My plan, in fact, after a installation of Gentoo... would be to shrink the 2
> TB partition that is currently formatted in NTS... (Windows 8), use the
> other partition formatted in ext 4 (i.e., Linux) data storage.
>
> Henry
> (who's trying hard to get away from windows, again (been using various
> flavors of Linux for about five years)
>
>

Henry,
A couple of points:

1) Not all computers will boot from an external USB drive. If you have
one around you can maybe do some experiments before you invest a lot
of time and find yourself stymied.

2) grub is not a requirement to boot Gentoo. There are links out there
demonstrating how to modify the Windows boot config files to allow you
to boot other OS's. I don't do it myself so I don't know what the
state of the Win 8 boot loader is in that respect, but there were ways
to do this with Win NT. If it's of interest then check it out.

Good luck,
Mark

Hy Henry,

if your system is able to boot from USB it is not problem to deploy
gentoo on external drive.

You can just install gentoo on that drive the same way as you will
install it on internal hdd. You will just install on /dev/sdb (or the
correct drive). Also the grub can be placed there. Just think of it as
a normal drive. Only difference is that you need usb, mass storage and
correct filesystem modules in kernel builtin or in initramfs. When
using external drive I would use better UUID when defining root in
fstab/grub, or better use LVM (I would use zfs, but thats pretty
different story).

Yes there are desktops without second hdd bay, even without another
sata connector, for example a lot of Dell SFF desktop computers.

Robert.


On Wed, 28 Aug 2013 16:39:47 -0400
"Henry W. Peters" <hwpeters@jamadots.com> wrote:

> On 8/28/2013 3:46 PM, czernitko wrote:
> > Hi, it seems improbable that your desktop PC would have only one
> > HDD slot. Could you post your exact model number please? :)
> > To give you some hope, I have had Linux installed on external hdd
> > for daily use for about two years. It is at least five years back,
> > it was over USB 2.0 and worked quite well. I did some photo editing
> > and retouching and it was ok.
> > How big is your internal drive anyway? Isn't it possible to use
> > around 30GB for Gentoo system partition? Or do you just want to
> > keep original hdd intact?
> > Regards,
> > Peter
> > ​
> > Hi,
> > If you really need a new drive (i.e. - the one that came with
> > your machine is just too small, etc.) then I'd look at imaging the
> > drive that's currently installed, putting in a larger drive,
> > partitioning this larger drive to hold both Gentoo and what ever M$
> > OS you might be using, and then just work to get both OS's working
> > but keep the current drive on the shelf as a backup. This way you
> > could always go back to what you have.
> >
> > Just an idea.
> >
> > Good luck,
> > Mark
> > To the point of the original poster: I currently use a Lenovo W520
> > laptop. I have a USB3 external hard drive that I mostly use for
> > backup, but I have occasionally edited some audio (small audio
> > files using Audacity) directly on the external drive. Again, it's
> > not the OS drive, so temp files and such are most likely stored on
> > the internal drive, but I know that Audacity operates in the
> > directory in which the project is located, so it's still doing a
> > fair bit of I/O to that external drive.
> >
> > Hope this helps!
> >
> > ~David
>
> Thanks all for helpful suggestions!
>
> First off, capacity of current internal drive is not really an issue
> with me... it is 2 TB... I tried installing Gentoo on another (very
> much older computer) a while ago & had problems installing Grub, with
> Gentoo, as I was dual booting with windows (not to mention conflicts
> with xstart & my old integrated SIS graphics card)... so my thinking
> is to install Gentoo on a whole other HD... which seemed to work out
> on my old computer (or perhaps it was simpler to do for a Gentoo
> novice, like myself).
>
> & Peter, I'm with you... I have not seen a desktop computer that
> didn't have at least one expansion bay (not that I've seen that
> many)... but apparently this HP Pavillion 500-046 does not. & I
> really had to dig to find out (the hard way).
>
> Good to hear that some have had some measure of success with external
> drives & Gentoo, rather sounds like I'll just have to try it...
>
> I have done a little more research since my earlier post, & I see
> that LaCie (& possibly others) make/sell an external drive that has
> usb 2 & 3/firewire 400 & 800/eSata (& there are, it seems, some extra
> Sata slots on the mother board of this HP computer).
>
> My plan, in fact, after a installation of Gentoo... would be to
> shrink the 2 TB partition that is currently formatted in NTS...
> (Windows 8), use the other partition formatted in ext 4 (i.e., Linux)
> data storage.
>
> Henry
> (who's trying hard to get away from windows, again (been using
> various flavors of Linux for about five years)
>
>

Whoaa, it seems you are right, Henry, according to the
specs<http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&lc=en&dlc=en&tmp_geoLoc=true&docname=c03769023#N1192>on
HP site this case really DOES have only one bay. It seems the
technician
was lying :(. Is there any chance of returning the PC for full refund as it
wasn't delivered per requested specs?
As for the Grub prublem, I thing you will not need any MBR boot loader. As
the computer is preinstalled with Windows 8, my bets are on UEFI firmware
in your motherboard which means your HDD should be in GPT format (no
old-fashioned MBR with all the gotchas). Booting UEFI might seem more
laborous for a novice, but if you read a few articles you will find it to
be way more reliable boot method than MBR/Grub. In fact, the only thing you
need to do is to build your gentoo kernel with EFI_STUB and few other
options, put your kernel bzImage on some fat32 partition and add a boot
entry into your UEFI(=bios). Most UEFIs are capable to work as boot
managers and boot loaders and they will do the Grub's work.
http://wiki.gentoo.org/wiki/UEFI_Gentoo_Quick_Install_Guide
Regards,
Peter


2013/8/28 Mark Knecht <markknecht@gmail.com>

> On Wed, Aug 28, 2013 at 1:39 PM, Henry W. Peters <hwpeters@jamadots.com>
> wrote:
> > On 8/28/2013 3:46 PM, czernitko wrote:
> >>
> >> Hi, it seems improbable that your desktop PC would have only one HDD
> slot.
> >> Could you post your exact model number please? :)
> >> To give you some hope, I have had Linux installed on external hdd for
> >> daily use for about two years. It is at least five years back, it was
> over
> >> USB 2.0 and worked quite well. I did some photo editing and retouching
> and
> >> it was ok.
> >> How big is your internal drive anyway? Isn't it possible to use around
> >> 30GB for Gentoo system partition? Or do you just want to keep original
> hdd
> >> intact?
> >> Regards,
> >> Peter
> >>
> >> Hi,
> >> If you really need a new drive (i.e. - the one that came with your
> >> machine is just too small, etc.) then I'd look at imaging the drive
> >> that's currently installed, putting in a larger drive, partitioning
> >> this larger drive to hold both Gentoo and what ever M$ OS you might be
> >> using, and then just work to get both OS's working but keep the
> >> current drive on the shelf as a backup. This way you could always go
> >> back to what you have.
> >>
> >> Just an idea.
> >>
> >> Good luck,
> >> Mark
> >> To the point of the original poster: I currently use a Lenovo W520
> laptop.
> >> I have a USB3 external hard drive that I mostly use for backup, but I
> have
> >> occasionally edited some audio (small audio files using Audacity)
> directly
> >> on the external drive. Again, it's not the OS drive, so temp files and
> >> such
> >> are most likely stored on the internal drive, but I know that Audacity
> >> operates in the directory in which the project is located, so it's still
> >> doing a fair bit of I/O to that external drive.
> >>
> >> Hope this helps!
> >>
> >> ~David
> >
> >
> > Thanks all for helpful suggestions!
> >
> > First off, capacity of current internal drive is not really an issue with
> > me... it is 2 TB... I tried installing Gentoo on another (very much older
> > computer) a while ago & had problems installing Grub, with Gentoo, as I
> was
> > dual booting with windows (not to mention conflicts with xstart & my old
> > integrated SIS graphics card)... so my thinking is to install Gentoo on a
> > whole other HD... which seemed to work out on my old computer (or
> perhaps it
> > was simpler to do for a Gentoo novice, like myself).
> >
> > & Peter, I'm with you... I have not seen a desktop computer that didn't
> have
> > at least one expansion bay (not that I've seen that many)... but
> apparently
> > this HP Pavillion 500-046 does not. & I really had to dig to find out
> (the
> > hard way).
> >
> > Good to hear that some have had some measure of success with external
> drives
> > & Gentoo, rather sounds like I'll just have to try it...
> >
> > I have done a little more research since my earlier post, & I see that
> LaCie
> > (& possibly others) make/sell an external drive that has usb 2 &
> 3/firewire
> > 400 & 800/eSata (& there are, it seems, some extra Sata slots on the
> mother
> > board of this HP computer).
> >
> > My plan, in fact, after a installation of Gentoo... would be to shrink
> the 2
> > TB partition that is currently formatted in NTS... (Windows 8), use the
> > other partition formatted in ext 4 (i.e., Linux) data storage.
> >
> > Henry
> > (who's trying hard to get away from windows, again (been using various
> > flavors of Linux for about five years)
> >
> >
>
> Henry,
> A couple of points:
>
> 1) Not all computers will boot from an external USB drive. If you have
> one around you can maybe do some experiments before you invest a lot
> of time and find yourself stymied.
>
> 2) grub is not a requirement to boot Gentoo. There are links out there
> demonstrating how to modify the Windows boot config files to allow you
> to boot other OS's. I don't do it myself so I don't know what the
> state of the Win 8 boot loader is in that respect, but there were ways
> to do this with Win NT. If it's of interest then check it out.
>
> Good luck,
> Mark
>
>

Henry W. Peters posted on Wed, 28 Aug 2013 15:24:36 -0400 as excerpted:

> So my question is: will an external HD work (I do audio
> editing/recording/graphics) as a system/work space? & more importantly,
> will Gentoo install on such a HD (external, usb 3))

USB-3 bus-speed, 5 Gbit/sec full duplex (previous USB was half-duplex and
USB-2 was 480 Mbit/sec), tho "reasonable" thruput is 3.2 Gbit/sec (400
MByte/sec), according to wikipedia, should be much faster than a
"spinning rust" hard drive, and indeed, should be reasonable as an SSD
bus, as well, altho SATA 3 (aka SATA 600) is a bit faster (6 Gbit/sec,
600 MByte/sec), and a good speed SSD bottlenecks on the SATA 3 bus. By
comparison, PCIE 1.x is 5 Gbit/sec at 2X, with PCIE 2.x 5 Gbit/sec at 1X
and PCIE 3.x 8 Gbit/sec at 1X.

Meanwhile, while drives do have a few megabyte of buffer (typically 16 or
32 MB), typical to-platter transfer rates run perhaps a quarter of that
(100 MByte/sec is quite good).

So you should EASILY be able to double-up on the "spinning rust" drives
on USB 3 and still have plenty of bandwidth to spare, tho SATA 2 was
indeed a bottleneck. If you're running a fast SSD, a dedicated USB 3
port will bottleneck on it compared to SATA 3, but not horribly so, and
it will still be MUCH faster than spinning rust.

Meanwhile, wikipedia's device bitrate table[1], from which I got the
above, also lists audio bitrates. CDA: 1.411 Mbit/sec. S/PDIF: 3.072
Mbit/sec, AC'97 12.288 MBit/sec. Even full-rate HDMI audio should be no
problem, at 36.864 Mbit/sec. Even USB 2 (480 Mbit/sec) should have
absolutely no problem with that, which is why USB sound cards are viable
and there's even some reasonably high end versions.

Uncompressed video, OTOH, could be a bit of a different story. HDMI 1.0
and single-link DVI are both 4.95 Gbit/sec, so will stress USB 3 and
SSDs. Full-speed dual-link DVI is 8.03 Gbit/sec, and HDMI 1.3 is 10.2
Gbit/sec, which will challenge any consumer-level storage today. PCIE of
sufficient version and/or X can handle it (thus the common 16X PCIE
graphics cards), but you'll be paying a pretty penny for storage of any
significant size that can keep up!

Which of course is why pretty much all video of significant resolution
and frame-rate is also significantly compressed -- it's pretty much
unmanageable, storage-wise, otherwise. But it doesn't sound like you're
doing that heavy video or you'd not be worried about sound at all.


Meanwhile, there's the whole "will it boot" question. However, as
someone else mentioned, MS Windows 8 almost certainly means UEFI, which
should be pretty flexible, provided of course that you're not running the
MS side too locked down (MS requires that UEFI be user unlockable on amd64
for certification, so you should be able to unlock it).

But beware, there are some USB drives that won't boot, at least not on
BIOS (I'm not sure about UEFI). One way around that is to stick grub or
whatever, along with the kernel (so basically your /boot) on a bootable
thumbdrive (which you can stick in a USB 2 slot since for just grub speed
isn't a huge issue) and boot it, then point the kernel at the otherwise
unbootable USB drive for root, since the kernel should be able to handle
even otherwise unbootable drives, once it's loaded. That's what I'm
doing here with my external-drive level of bootable system backup, since
the drive isn't otherwise bootable.

---
[1] https://en.wikipedia.org/wiki/List_of_device_bit_rates

--
Duncan - List replies preferred. No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master." Richard Stallman

On Wed, Aug 28, 2013 at 3:24 PM, Henry W. Peters <hwpeters@jamadots.com> wrote:
> So my question is: will an external HD work (I do audio
> editing/recording/graphics) as a system/work space? & more importantly, will
> Gentoo install on such a HD (external, usb 3))
>

You did mention USB3, as did others in this thread. Hopefully this is
obvious to all, but under no circumstances should you try to run an OS
on USB2 or less. eSATA or USB3 should in theory be fine, though I
have no experience with the latter (I guess in theory it should work
fine).

Sure, any USB will work, but for USB2 or lower you'll start to get an
experience that feels more like booting off of a LiveCD.

Rich

On Wed, Aug 28, 2013 at 3:39 PM, Henry W. Peters <hwpeters@jamadots.com> wrote:
> I have not seen a desktop computer that didn't have at least one expansion
> bay (not that I've seen that many)... but apparently this HP Pavillion
> 500-046 does not. & I really had to dig to find out (the hard way).

You could remove the 3.5" drive and put in a bracket that holds two
2.5" drives in a single 3.5" slot. Then you could put in a pair of
SSDs or an SSD and a laptop hard drive. Or remove the optical drive
and do the same thing there.

On Thu, 2013-08-29 at 14:58 -0500, Paul Hartman wrote:
> On Wed, Aug 28, 2013 at 3:39 PM, Henry W. Peters <hwpeters@jamadots.com> wrote:
> > I have not seen a desktop computer that didn't have at least one expansion
> > bay (not that I've seen that many)... but apparently this HP Pavillion
> > 500-046 does not. & I really had to dig to find out (the hard way).
>
> You could remove the 3.5" drive and put in a bracket that holds two
> 2.5" drives in a single 3.5" slot. Then you could put in a pair of
> SSDs or an SSD and a laptop hard drive. Or remove the optical drive
> and do the same thing there.

double sided tape and mount ssd to bottom of drive enclosure.

use the pciex16 slot:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820785002
or one of its friends; not meaning to do a commercial

On Thu, 2013-08-29 at 16:27 -0400, Drake Donahue wrote:
> On Thu, 2013-08-29 at 14:58 -0500, Paul Hartman wrote:
> > On Wed, Aug 28, 2013 at 3:39 PM, Henry W. Peters <hwpeters@jamadots.com> wrote:
> > > I have not seen a desktop computer that didn't have at least one expansion
> > > bay (not that I've seen that many)... but apparently this HP Pavillion
> > > 500-046 does not. & I really had to dig to find out (the hard way).
> >
> > You could remove the 3.5" drive and put in a bracket that holds two
> > 2.5" drives in a single 3.5" slot. Then you could put in a pair of
> > SSDs or an SSD and a laptop hard drive. Or remove the optical drive
> > and do the same thing there.
>
> double sided tape and mount ssd to bottom of drive enclosure.
>
> use the pciex16 slot:
> http://www.newegg.com/Product/Product.aspx?Item=N82E16820785002
> or one of its friends; not meaning to do a commercial
should add, linux driver not known to me

Rich Freeman posted on Thu, 29 Aug 2013 15:56:10 -0400 as excerpted:

> On Wed, Aug 28, 2013 at 3:24 PM, Henry W. Peters <hwpeters@jamadots.com>
> wrote:
>> So my question is: will an external HD work (I do audio
>> editing/recording/graphics) as a system/work space? & more importantly,
>> will Gentoo install on such a HD (external, usb 3))
>>
>>
> You did mention USB3, as did others in this thread. Hopefully this is
> obvious to all, but under no circumstances should you try to run an OS
> on USB2 or less.

People did it for years before USB3 and SATA2/3 arrived... and they did
it without the gigs of RAM often available for cache these days, too. It
certainly shouldn't be slower now than it was then, and with anything
even close to reasonable in terms of modern memory size (once we're
measuring in gigs, preferably 2+ but even a gig will help quite a bit),
it should be quite fast once the base system gets loaded.

Actually, USB2 is 480 Mbit/sec (as mentioned in my other reply), so
should do probably 30-40 MB/sec transfer, as long as it's the only thing
on the USB port. Sure, spinning rust storage is rated higher for
sequential I/O, but it's not /that/ much faster for random access due to
seek times. A good spinning rust disk might do twice that on good SATA
if you're lucky, not much more, particularly if it and the machine in
general are of USB2 or earlier vintage. So USB2 is likely to be a bit
slower with spinning rust, but not hugely so. And again, once the data's
in cache...

Just don't try to use the same USB2 port via hub or whatever to handle
keyboard/mouse/whatever-else as well.

But USB1.1 ... yes, THAT's slow!

And a good SSD would work on USB2, but I'm not sure why one would do it,
unless one had a spare laying around gathering dust... For that you
definitely want USB3 or SATA3 (tho SATA2 is half SATA3 speed so should
still be noticeably faster than spinning rust or USB2).

> eSATA or USB3 should in theory be fine, though I have
> no experience with the latter (I guess in theory it should work fine).
>
> Sure, any USB will work, but for USB2 or lower you'll start to get an
> experience that feels more like booting off of a LiveCD.

... Which as I said isn't too bad once it either loads to RAMDisk or gets
cached, as long as there's enough memory for that, of course, but 2+ gigs
should be quite reasonably usable, and most anything half modern should
have that, unless we're talking embedded, something like a router.

--
Duncan - List replies preferred. No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master." Richard Stallman

On Fri, Aug 30, 2013 at 9:40 PM, Duncan <1i5t5.duncan@cox.net> wrote:
> Rich Freeman posted on Thu, 29 Aug 2013 15:56:10 -0400 as excerpted:
>> You did mention USB3, as did others in this thread. Hopefully this is
>> obvious to all, but under no circumstances should you try to run an OS
>> on USB2 or less.
>
> People did it for years before USB3 and SATA2/3 arrived...

Anybody with a motherboard supporting USB2 almost certainly had a
motherboard supporting PATA at a faster transfer rate.

I do agree that random access speed does lower the effective rate. My
hard drives are running at 3GB/s transfer rates each on a dedicated
channel, and yet they're probably not any faster than they would have
been under PATA (assuming one drive per cable).

Hopefully one of these days there will be a decent SSD cache option
for Linux. Bcache is still fairly experimental, and I'm not sure how
well it performs in practice with btrfs - plus it is a device layer
and not filesystem layer implementation (ie if you have mirrored
drives you end up with mirrored cache which seems a bit dumb,
especially if the mirrors end up being on separate partitions on the
same device).

Rich

Rich Freeman posted on Fri, 30 Aug 2013 21:50:47 -0400 as excerpted:

> Anybody with a motherboard supporting USB2 almost certainly had a
> motherboard supporting PATA at a faster transfer rate.

[.Long winded and thread tangential. TL;DR readers just skip it, but I
know some people find these things interesting/useful. There's some SSD
deployment discussion further down that I certainly could have used a few
months ago!]

Well, yes, but...

With my 8-year-old native USB1 (with a USB2 addon card, it wouldn't do
USB3 as it didn't have PCIE, only PCI-X, dual socket original 3-digit
Opteron maxed out at dual Opteron-290, which are dual-core @ 2.8 GHz, so
it was effectively quad-core at 2.8, not /too/ shabby, just getting
seriously dated in terms of buses, etc) system that died last year, I
setup an unbootable USB external spinning rust drive as a backup, with a
USB thumbdrive on the bootable native USB1 for /boot to load the kernel,
which could then handle the PCI-card USB2 that the BIOS couldn't, and
thus get to the backup root on the external USB2 spinning rust.

That's how I know that not all external USB devices are bootable, as that
external drive wasn't, even when I had it on the bios-supported native
USB1, thus the earlier warning about that, and how to work around it.

But the point is, that setup wasn't /significantly/ slower in normal
operation than my fancy multi-disk md-raid, and in fact, was NOTICEABLY
faster than my original mdraid-6 setup (thus the discussion on it a few
months ago), tho mdraid-1 was a bit faster after I switched to it,
particularly for multi-thread read as typically happens during boot.

Now for transferring hundreds of megabytes (as when actually making the
backups), yeah, doing that over the USB2 was a bit slow, roughly
comparable to backing up to a different partition on the same spindle
internally (with the disk seeks that means, except that backing up to the
external was to a separate external physical device so without the USB2
bottleneck it should have been faster). However, for ordinary use, the 6
gigs of RAM (at one point 8, two 2-gig sticks per socket, but one stick
died and I never replaced it) was plenty to cover both my normal memory
usage and working set disk cache with reasonable margin to spare as I
normally run only 2-3 gigs apps+buffers+cache (top line of free), except
when I'm doing updates or large media files and thus have all that cached
too.

But even cold-booting off the USB2 external was enough faster than the
mdraid-6 to demonstrate how bad mdraid6 can be, and convince me to switch
to mdraid-1, which was indeed faster.

> I do agree that random access speed does lower the effective rate. My
> hard drives are running at 3GB/s transfer rates each on a dedicated
> channel, and yet they're probably not any faster than they would have
> been under PATA (assuming one drive per cable).
>
> Hopefully one of these days there will be a decent SSD cache option for
> Linux. Bcache is still fairly experimental, and I'm not sure how well
> it performs in practice with btrfs - plus it is a device layer and not
> filesystem layer implementation (ie if you have mirrored drives you end
> up with mirrored cache which seems a bit dumb, especially if the mirrors
> end up being on separate partitions on the same device).

Here, I ended up putting root and home (and log and the gentoo tree and
overlays and...) on btrfs on SSD, with, effectively, only my media (and
secondary backups) remaining on spinning rust, as I couldn't justify the
cost to put it on SSD.

A 64-gig SSD is now well below the best-price-point knee at least around
here, and I calculated that would be minimal for working copy and primary
backup of the OS and /home. However, once I looked at prices (as of a
few months ago), I found 128 gig SSDs were actually the low end of the
price-point-knee, with 256 gig the high end, and decided the over-
provisioning would be a good idea due to the limited write-cycle issue on
multi-level SSDs, so actually planned on that.

But when I went in to Fry's Electronics to buy, turned out all their good
deals on 128 gig SSDs were selling out faster than they could get them in
stock, and they happened to be out of the good deals there. I use public
transit and didn't feel like going home empty handed only to come back
the day the truck came in, so I ended up with 256 gig SSDs, still at the
price-point-knee tho at the upper end of it, and was able to put even
MORE on the SSDs -- while still keeping a very healthy nearly 100% over-
provisioning, tho I expect that might dwindle a bit over time. (With 16
GiB RAM I decided I didn't need swap.)

I did spend a bit more than planned, buying three of them, two for the
main machine, now mostly configured in btrfs raid1 mode in ordered to
actually make use of btrfs' data integrity checksumming and scrub
abilities, with the third to eventually be used in my netbook (which
being SATA2 will bottleneck on that, but the slower ones weren't
significantly cheaper, and I expect it'll outlast my netbook, to be used
either in my main machine or a netbook replacement, later, at which point
I'll probably actually use the full speed, as I do with the other two
now). But I've been working extra hours and will have it paid off
~three months from purchase so not so much interest, and I'm happy with
it.

The point being... if you do your partitioning right, you can get 90% of
the benefits of full SSD at *FAR* more reasonable costs than full SSD.
Basically SSD caching, only without the cache, simply putting the stuff
that will truly benefit from SSD on SSD, while leaving the stuff that
won't on cheaper spinning rust. I calculated that I only NEEDED about 64
GB for the most important stuff, with backups on spinning rust, and that
would have left a healthy over-provisioning too. (I figured I could fit
what I really wanted on SSD in 32 gig if I had to, but it would have been
a pretty tight fit!)

Here's my gdisk -l output for one of the SSD pair (I've been running GUID
Partition Tables, GPT, for some time now, some boilerplate omitted for
posting):

Disk /dev/sda: 500118192 sectors, 238.5 GiB
Partition table holds up to 128 entries
Partitions will be aligned on 2048-sector boundaries
Total free space is 246364781 sectors (117.5 GiB)

No. Start(sector) End(sector) Size Code Name
1 2048 8191 3.0 MiB EF02 bi0238gcn1+35l0
2 8192 262143 124.0 MiB EF00 ef0238gcn1+35l0
3 262144 786431 256.0 MiB 8300 bt0238gcn1+35l0
4 786432 2097151 640.0 MiB 8300 lg0238gcn1+35l0
5 2097152 18874367 8.0 GiB 8300 rt0238gcn1+35l0
6 18874368 60817407 20.0 GiB 8300 hm0238gcn1+35l0
7 60817408 111149055 24.0 GiB 8300 pk0238gcn1+35l0
8 111149056 127926271 8.0 GiB 8300 nr0238gcn1+35l0
9 127926272 144703487 8.0 GiB 8300 rt0238gcn1+35l1
10 144703488 186646527 20.0 GiB 8300 hm0238gcn1+35l1
11 186646528 236978175 24.0 GiB 8300 pk0238gcn1+35l1
12 236978176 253755391 8.0 GiB 8300 nr0238gcn1+35l1

I wanted my partitions 4 MiB aligned for efficient erase-block handling,
tho the first one's only 1 MiB aligned.

One of the features of GPT partitioning is that it allows partition
names/labels much like filesystems normally do. That's what's shown in
the last column. I have a standard naming scheme, developed back when I
was running multiple mdraid devices, some of which were themselves
partitioned, on a 4-spindle set, that I use for both my partition labels
and my filesystem labels, for both my main machine and my netbook:

* 15 characters long
123456789012345
ff bbB ymd
ssssS t n

Using a different example from my mdraid days:

rt0005gmd3+9bc0

ff: 2-char function abbreviation

bi=bios (gpt dedicated legacy BIOS boot partition, used by grub2).
ef=efi (gpt dedicated efi partition, unused here ATM but reserved for
forward compatibility)
bt=boot, lg=log, rt=root, hm=home, lg=log, pk=package (gentoo tree,
layman overlays, sources, binpkgs, kernel tree), nr=netbook-root
(separate 32-bit chroot build-image filesystem/partition).

Example rt=root

Device-ID consisting of ssssSbbB:
ssssS: 4-digit size, 1-char multiplier. This is the size of the
underlying/containing media, NOT the partition/filesystem (I'm IDing the
containing device).

bbB: 2-char media brand ID, 1-digit sequence number.

The md example is a 5 GiB mdraid volume (/dev/md3), which might itself be
partitioned (IIRC I was keeping /usr/local/ on a separate filesystem/
partition on the same mdraid as root, back then).

In the above output, 0238 GiB, corsair neutron. The paired SSDs are 0
and 1 (0 is installed as sdb, 1 as sda, as I reversed them in
installation). So the device-ids are 0238gcn1 and 0238gcn0, with the
common btrfs on top of both device-IDed as 0238gcnx.

t: single-char target/separator. This serves as both a target ID and a
visual separator.

I use . for my netbook (dot 'cause it's small), + for the main machine,
and % for portable disk partitions intended to be used on both.

Both the output and the md example are for my main machine, so +.

ymd: 1-char-each year/month/day.

y=last digit of year (I might use storage devices for years but it's
unlikely I'll need to track decade wrap).
m=month (1-9abc)
d=day (1-9a-v)

This is generally the day I setup the partition. Back when I was still
on MBR I used to relabel the filesystem on my backup partitions with the
new date when I did a mkfs and a clean backup, but when I switched to GPT
and could label the partitions too I decided to keep them date-matched as
my fstab uses LABEL= mounting, and it was a hassle updating the fstab
when I blew away an old backup and redid it.

The md example is 2009-11-12. The table is using 2013-05-21.

n: 1-digit copy number. The working copy is 0, primary backup 1...

The md example is the working copy. The table has the working copy and
for some partitions the primary backup.


mdraid example all together: rt0005gmd3+9bc0
rt root
0005gmd3 5-gig /dev/md3
+ for use on the main machine
9bc 2009-11-12 (Nov 12)
0 working copy


So from the above you can see I have a 3 MiB BIOS partition (grub2 uses,
per-drive, size chosen to put all later partitions on 4 MiB boundaries),
a 124 MiB EFI partition (reserved for future use, later partitions are
now on 128 MiB boundaries).

A 256 MiB /boot comes next. (This is a separate filesystem for each
drive, the second one for backup, working copy updated every time I
install a new kernel, which I do a lot as I run git kernels, backup
updated once per cycle with the 3.x.0 release, I can direct the BIOS at
either one or at the spinning rust /boot, my secondary /boot backup).

That's followed by /var/log at 640 MiB, leaving me at 1 GiB boundaries.
This partition and later are btrfs raid1 mode, but I only keep the
working copy of log, not the working and backup copies I keep for
everything else.

Then come the root (8 GiB), home (20 GiB), package (24 GiB), and netbook-
root-build-image (8 GiB) partitions, working copies followed by primary
backups. Secondary backups and media remain as I said on spinning rust.
That's the bulk of my data but it's also the least speed-critical.

As you can see with a bit of math (I can cheat here and just look it up
in gdisk), that's 121 GiB used, 117.5 GiB free, just worse than 50/50, so
near 100% over-provisioning. I shouldn't have to worry too much about
write-cycle wear-out with that, even if I add a few gigs of partitions
later. (Recommended SSD overprovisioning is 25-33%, thus actually using
3/4-4/5. I'm barely over half! =:^)

With a bit more squeezing I could have fit home and both main root and
netbook root on a 32-gig with no overprovisioning, and a 64 gig would
have fit 1 copy of everything listed, with the primary backups on
spinning rust, and that or an 80 gig to allow a bit of overprovisioning
is what I was originally targeting. Then I looked at the prices and saw
128 gigs at not /that/ much over 80 gigs and at a cheaper per-gig, so
that's what I actually thought I'd buy. But I'm not complaining about
the 256 gig (238 GiB, unfortunately they're carrying over the marketing
practices from spinning rust, I AM complaining about that!), and I'm
*DEFINITELY* not complaining about boot or emerge --sync speed on the
SSDs! =:^)

--
Duncan - List replies preferred. No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master." Richard Stallman

On Sat, Aug 31, 2013 at 6:53 AM, Duncan <1i5t5.duncan@cox.net> wrote:
> The point being... if you do your partitioning right, you can get 90% of
> the benefits of full SSD at *FAR* more reasonable costs than full SSD.

That has been some of my thinking as well. I could just stick the OS
on SSD and run frequent backups to RAID if I'm worried about it. Most
of the stuff that changes frequently on my system is cloud-based
anyway these days - the biggest exception to that is MythTV video and
that will go straight to RAID.

Rich

Rich Freeman posted on Sat, 31 Aug 2013 07:00:45 -0400 as excerpted:

> [T]he biggest exception to that is MythTV video and that will go
> straight to RAID.

No kidding on that. SSD for the terabytes of video I know some people
store would be EXPENSIVE indeed! =:^( Luckily, spinning rust works fine
for that. =:^)

--
Duncan - List replies preferred. No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master." Richard Stallman