Aggregate snapshots are also used by the 'aggr copy' filer command,
which is the aggregate-level version of 'vol copy'. This copies an
aggregate and all its flexible volumes from one location to
another, using aggregate snapshots to get a consistent image.
-----Original Message-----
From: Skottie Miller [mailto:skottie@anim.dreamworks.com]
Sent: Wednesday, April 27, 2005 12:29 AM
To: Derek Lai
Cc: Steve Losen; toasters(a)mathworks.com
Subject: Re: Aggregate snapshots?
Derek Lai wrote:
> Is this documented well anywhere? I've just started playing with
> DataOntap 7.0 on the new FAS250 we bought. I've looked through NOW and
> can't seem to find good documentation regarding Aggregate Snapshots.
it's not documented well in any of the docs I have; my understanding is
based on conversations with my SE and from a recent "7G migration"
webcast.
> It looks like there are a number of commands now that has -A options
> added, i.e. snap list -A to list the aggregate snapshot. Would be nice
> to know what Aggregate Snapshot are designed to do. There does not
> seem to be anything in filerview that lets you work with Aggregate
> snapshots?
the use of -A is consistant throughput the command set; every command
that you're using to using for a traditional volume works for volumes,
and the -A version us ised to deal with the underlying aggregates.
since we don't use RAID SyncMirror, my best practice for aggregate
snapshots will be to disable them and to reclaim the space. If some
compelling reason to use them can be explained to me, then I'll
re-enable them.
-skottie
>
>
> Derek
>
> -----Original Message-----
> From: Skottie Miller [mailto:skottie@anim.dreamworks.com]
> Sent: Monday, April 25, 2005 11:53 AM
> To: Steve Losen
> Cc: toasters(a)mathworks.com
> Subject: Re: Aggregate snapshots?
>
>
> My understanding of aggregate snapshots is that they provide an
> additional layer of snapshot protection, and are useful in some
> environments.
>
> restoring an aggregate snapshot restores *all* the flexVols within
> that aggregate. aggregate snapshots are required if you use RAID
> SyncMirror and/or MetroCluster configurations. or of you want to
> snaprestore a whole aggregate (seems dangerous).
>
> Note that aggregate snapshots aren't allowed to grow abouve the
> reserve, and will "autodelete" themselves to maintain space.
>
> on my test filers and in my test use of the simulator, I've been
> running with aggregate snapshots disabled and the reserve set to 0.
> NetApp "discourages" this, but unless they send me 5% more disks,
> free, I want that space back for production.
>
> -skottie
>
> Steve Losen wrote:
>
>>We just got a R200 and FAS960c and I immediately upgraded them from
>>6.5 to 7.0.0.1. I moved the root volume to a flex vol and destroyed
>>the old root, so now I have one big aggregate that contains the root
>>volume.
>>
>>I discovered the "df -A" command and was surprised to see that my
>>aggregate has snap reserve space, a snap sched running, and five
>>snapshots. This is independent of the snap reserve and sched of my
>>root volume.
>>
>>What is the rationale behind aggregate snapshots? We don't have
>>snapmirror licensed. Can you snapmirror them? Can you snaprestore
>>them? I presume this mirrors (or restores) the entire aggregate.
>>I doubt that you can access aggregate snapshots from a NFS or CIFs
>>client, or can you? Can you somehow tease out volumes from an
>>aggregate snapshot and NFS export them? Within an aggregate snapshot,
>>do you have just the active volumes, or the volumes and all of their
>>volume level snapshots as they existed at the time the aggregate
>>snapshot was taken? Mind boggling.
>>
>>I am probably going to set the snap reserve on my aggregates to zero
>>and turn off the snap sched and manage my snapshots at the volume
>>level. Any reason to not do that? Using both aggregate and volume
>>snapshots looks about the same as using a belt and suspenders to keep
>>your pants up.
>>
>>Steve Losen scl(a)virginia.edu phone: 434-924-0640
>>
>>University of Virginia ITC Unix Support
>>
>>
>
>