[lustre-discuss] [EXTERNAL] ran out of MDT inodes

[Mohr, Rick]

Liam,

I found the slides for the talk I was referring to:

https://www.opensfs.org/wp-content/uploads/2017/06/Wed06-CroweTom-lug17-ost_data_migration_using_ZFS.pdf

The example in the talk used the -R option (as Shane mentioned).

-Rick

On 9/16/22, 1:44 PM, "Nehring, Shane R [LAS]" <snehring at iastate.edu> wrote:

    You would probably also want to make sure you specify either -p or -b (or -R)
    when you do the zfs send to make sure the properties are sent as well. Lustre
    stores some information about the volume some custom properties. Forgetting that
    has bitten me in the past.

    Shane

    On Fri, 2022-09-16 at 17:01 +0000, Mohr, Rick via lustre-discuss wrote:
    > Liam,
    > 
    > As far as I know, all the data contained in ZFS would be transferred (Lustre
    > or otherwise).  We were able to move an mdt to new storage on a different
    > server with no known issues.  There was also a talk at LUG several years ago
    > given by a site that would use ZFS snapshots as a safeguard during Lustre
    > upgrades so that they could easily roll back if needed.  Perhaps that would be
    > of use to you.  I can't remember which year it was, but it may have been the
    > one hosted at IU.  Anyway, all the old LUG talks/slides should be online so if
    > you dig around you should be able to find it. 
    > 
    > -Rick
    > 
    > On 9/16/22, 12:06 PM, "Liam Forbes" <loforbes at alaska.edu> wrote:
    > 
    >     Morning Rick!
    > 
    >     At first we were planning to do that. However, we weren't sure if that
    > would capture all the internal Lustre data. Specifically the note in 18.3.1
    > about index backups made us think it wouldn't for version 2.10.X. Also the
    > fact that ldiskfs backups and LVM snapshots are detailed in the manual but ZFS
    > snapshots are not caused us to think they wouldn't work, at least with our
    > older lustre version. Maybe we were taking things too literally. Would a ZFS
    > snapshot contain all the Lustre data?
    > 
    > 
    > 
    >     On Fri, Sep 16, 2022 at 7:45 AM Mohr, Rick <mohrrf at ornl.gov> wrote:
    > 
    > 
    >     Liam,
    > 
    >      If you have another zpool configured somewhere, you could always take a
    > snapshot of your mdt and then used send/received to copy that snapshot to
    > another zpool.  I helped someone do this one time in order to move the mdt to
    > new hardware.
    > 
    >     -Rick
    > 
    > 
    > 
    > 
    >     -- 
    >     Regards,
    >     -liam
    > 
    >     -There are uncountably more irrational fears than rational ones. -P. Dolan
    >     Liam Forbes           loforbes at alaska.edu                       ph:
    > 907.450.8618
    >     UAF GI Research Computing Systems Manager
    >     hxxps://calendly.com/ualoforbes/30min
    > 
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