[gpfsug-discuss] [EXTERNAL] mmbackup vs SOBAR

Peter Childs p.childs at qmul.ac.uk
Thu Mar 9 16:07:43 GMT 2023


I've been told "you really should be using SOBAR" a few times, but never really understood how to do so and the steps involved. I feel sure it should have some kind of white paper, so far I've been thinking to setup some kind of test system, but get a little lost on where to start (and lack of time).

We currently use mmbackup to x2 servers using `--tsm-servers TSMServer1, TSMServer2` to have two independant backups and this works nicely until you lose a tape when restoring that tape is going to be a nightmare. (read rebuild the whole shadow database)

We started with a copy pool until we filled our tape library up, and then swapped to Protect replication until we found this really did not work very well (really slow and missing files), and IBM surgested we use mmbackup with 2 servers and have two independ backups, which is working very well for us now.

I think if I was going to implement SOBAR I'd want to run mmbackup as well as SOBAR will not give you point in time recovery or partial recovery and is really only a disarster solution. I'd also probably want 3 copies on tape, 1 in SOBAR, and 2x via mmbackup via two backups or via a copy pool

I'm currently thinking to play with HSM and SOBAR on a test system, but have not started yet...... Maybe a talk at the next UG would be helpful on backups, I'm not sure if I want to do one, or if we can find an "expert"

Peter Childs



________________________________________
From: gpfsug-discuss <gpfsug-discuss-bounces at gpfsug.org> on behalf of Robert Horton <robert.horton at icr.ac.uk>
Sent: Thursday, March 9, 2023 3:44 PM
To: gpfsug-discuss at gpfsug.org
Subject: [EXTERNAL] [gpfsug-discuss] mmbackup vs SOBAR

CAUTION: This email originated from outside of QMUL. Do not click links or open attachments unless you recognise the sender and know the content is safe.

Hi Folks,

I’m setting up a filesystem for “archive” data which will be aggressively tiered to tape using the Spectrum Protect (or whatever it’s called today) Space Management. I would like to have two copies on tape for a) reading back the data on demand b) recovering accidentally deleted files etc c) disaster recovery of the whole filesystem if necessary.

My understanding is:

  1.  Backup and Migration are completely separate things to Spectrum Protect. You can’t “restore” from a migrated file nor do a DMAPI read from a backup.
  2.  A SOBAR backup would enable the namespace to be restored if the filesystem were lost but needs all files to be (pre-)migrated and needs the filesystem blocksize etc to match.
  3.  A SOBAR backup isn’t much help for restoring individual (deleted) files. There is a dsmmigundelete utility that restores individual stubs but doesn’t restore directories etc so you really want a separate backup.

My thinking is to do backups to one (non-replicated) tape pool and migrate to another and run mmimgbackup regularly. I’d then have a path to do a full restore if either set of tapes were lost although it seems rather messy and it’s a bit of a pain that SP needs to read everything twice.

So… have I understood that correctly and does anyone have any better / alternative suggestions?

Thanks,
Rob

Robert Horton | Scientific Computing Infrastructure Lead
The Institute of Cancer Research | 237 Fulham Road, London, SW3 6JB
T +44 (0) 20 7153 5350 | E robert.horton at icr.ac.uk<mailto:robert.horton at icr.ac.uk> | W www.icr.ac.uk<http://www.icr.ac.uk/> | Twitter @ICR_London<https://twitter.com/ICR_London>
Facebook www.facebook.com/theinstituteofcancerresearch<http://www.facebook.com/theinstituteofcancerresearch>
Making the discoveries that defeat cancer
[ICR Logo]<http://www.icr.ac.uk/>


The Institute of Cancer Research: Royal Cancer Hospital, a charitable Company Limited by Guarantee, Registered in England under Company No. 534147 with its Registered Office at 123 Old Brompton Road, London SW7 3RP.

This e-mail message is confidential and for use by the addressee only. If the message is received by anyone other than the addressee, please return the message to the sender by replying to it and then delete the message from your computer and network.




More information about the gpfsug-discuss mailing list