Mailing List Archive: Re: I have 2 volumes in the same raid group, though the docs say you

Re: I have 2 volumes in the same raid group, though the docs say you

Aug 9, 2002, 3:50 PM

Post #1 of 3 (1107 views)

art@arzoon.com (Art Hebert) writes:
>
> I have 7 disks in vol0 in raid group 0 and 2 disks in vol1 in
> raid group 0.
>
> In the manual it seems to say you can't do this. Will this cause
> any problems?

Well, a 2-disk volume (1 parity + 1 data) is far from optimal for
performance. [.I am more than usually aware of that at the moment,
as I have been running test restores to a 1+1 /vol/test and they
are noticably slower as a result.] But there's no law against it,
and some toastees like to use just such a volume as their root,
as we've been hearing again recently.

Is the same filer as you were talking about in the other thread?

Chris Thompson
Email: cet1@cam.ac.uk

Re: I have 2 volumes in the same raid group, though the docs say you [ In reply to ]

cet1 at cus

Aug 9, 2002, 4:18 PM

Post #2 of 3 (1077 views)

Permalink

art@arzoon.com (Art Hebert) writes:
>
> I have 7 disks in vol0 in raid group 0 and 2 disks in vol1 in
> raid group 0.
>
> In the manual it seems to say you can't do this. Will this cause
> any problems?

Oops: just reread your subject field, and I see what you are confused
about now...

The "raid group 0" in each volumes are separate raid groups: it's
just a naming convention. They each have their own parity disc, as
'sysconfig -r" will tel you. Raid groups are never shared between
volumes.

In ONTAP 6.2, "sysconfig -r" gives names to the raid groups like
"/vol0/plex0/rg0" and "/vol1/plex0/rg0", making it more obvious
that they are distinct entities.

Chris Thompson
Email: cet1@cam.ac.uk

RE: I have 2 volumes in the same raid group, though the docs say you [ In reply to ]

Martin.Kenley at netapp

Aug 9, 2002, 5:31 PM

Post #3 of 3 (1085 views)

Permalink

This is correct, whenever you create a volume
the 1st raid group by default is named Raid Group 0,
and if the vol is sufficiently large to need a
second Raid Group, it will be called RG1, etc.

Martin

-----Original Message-----
From: Chris Thompson [mailto:cet1@cus.cam.ac.uk]
Sent: Friday, August 09, 2002 4:18 PM
To: art@arzoon.com
Cc: toasters@mathworks.com
Subject: Re: I have 2 volumes in the same raid group, though the docs
say you

art@arzoon.com (Art Hebert) writes:
>
> I have 7 disks in vol0 in raid group 0 and 2 disks in vol1 in
> raid group 0.
>
> In the manual it seems to say you can't do this. Will this cause
> any problems?

Oops: just reread your subject field, and I see what you are confused
about now...

The "raid group 0" in each volumes are separate raid groups: it's
just a naming convention. They each have their own parity disc, as
'sysconfig -r" will tel you. Raid groups are never shared between
volumes.

In ONTAP 6.2, "sysconfig -r" gives names to the raid groups like
"/vol0/plex0/rg0" and "/vol1/plex0/rg0", making it more obvious
that they are distinct entities.

Chris Thompson
Email: cet1@cam.ac.uk