Having never been able to to attend Netapp classes, bear with me if these
are fairly simple.
1) CIFS was purchased but never actually used. It currently shows up when
you type license.
Will this in anyway affect the Netapp nfs performance?
2) Does disk scrubbing run automatically daily and if so is this
changeable, by day, by time?
3) Can somebody give me the rundown on running wack? This is what I have
off the net (somehow the
this is how you do it part never got published).
When to use WACK on a NetApp Filer
From an email by Dave Hitz (12/1999) on the Toasters mailing list.
The main difference between "wack" and fsck or scandisk is that you
shouldn't need to run wack during normal operation.
In particular, unlike UNIX and NT, you don't need to run "wack" after a
system panic, or when you pull the plug without shutting the system down, or
after a power failure. The WAFL filesystem uses a database technique called
"shadow paging with NV-RAM log replay" to maintain a fully consistent state
on disk even in the face of unexpected shutdowns.
So when do you need to run wack? Suppose that you have a disk fail in RAID,
and then when you try to reconstruct the data from the lost disk you
discover that there is a bad sector on one of the other drives. Most of your
file system data is just fine, but you've got a couple of blocks that can't
be recovered. The RAID subsystem zeros both blocks, since that's the best
that you can do, but now you need to run wack in order to fix things up, in
case the zeroed blocks contained file system data like inodes, indirect
blocks, or the free block map.
And yes, I must confess that like any computer, NetApp systems do contain
the occasional bug, so WAFL has a number of checks to make sure that the
on-disk data looks reasonable, and if it finds a problem it will ask you to
perform a wack.
Our goal is for customers never to need to run wack, but the reality is that
people sometimes do need to use it. this is how you do it.
Thanks
art hebert
are fairly simple.
1) CIFS was purchased but never actually used. It currently shows up when
you type license.
Will this in anyway affect the Netapp nfs performance?
2) Does disk scrubbing run automatically daily and if so is this
changeable, by day, by time?
3) Can somebody give me the rundown on running wack? This is what I have
off the net (somehow the
this is how you do it part never got published).
When to use WACK on a NetApp Filer
From an email by Dave Hitz (12/1999) on the Toasters mailing list.
The main difference between "wack" and fsck or scandisk is that you
shouldn't need to run wack during normal operation.
In particular, unlike UNIX and NT, you don't need to run "wack" after a
system panic, or when you pull the plug without shutting the system down, or
after a power failure. The WAFL filesystem uses a database technique called
"shadow paging with NV-RAM log replay" to maintain a fully consistent state
on disk even in the face of unexpected shutdowns.
So when do you need to run wack? Suppose that you have a disk fail in RAID,
and then when you try to reconstruct the data from the lost disk you
discover that there is a bad sector on one of the other drives. Most of your
file system data is just fine, but you've got a couple of blocks that can't
be recovered. The RAID subsystem zeros both blocks, since that's the best
that you can do, but now you need to run wack in order to fix things up, in
case the zeroed blocks contained file system data like inodes, indirect
blocks, or the free block map.
And yes, I must confess that like any computer, NetApp systems do contain
the occasional bug, so WAFL has a number of checks to make sure that the
on-disk data looks reasonable, and if it finds a problem it will ask you to
perform a wack.
Our goal is for customers never to need to run wack, but the reality is that
people sometimes do need to use it. this is how you do it.
Thanks
art hebert