[lustre-discuss] Backup software for Lustre

Sat Mar 18 20:51:04 PDT 2017

Hi Andreas, I expected that to be the case, but found out it was not.
Instead, the restore restores everything - unless directed otherwise.

Backup == cmd + add xattrs.
Restore == cmd + exclude xattrs.

Brett
--
Protect Yourself Against Cybercrime
PDS Software Solutions LLC
https://www.TrustPDS.com
On Mar 18, 2017 9:28 PM, "Dilger, Andreas" <andreas.dilger at intel.com> wrote:

> Do you need to specify --xattrs (or similar) during the restore phase as
> well?
>
> Cheers, Andreas
>
> On Mar 17, 2017, at 15:12, Brett Lee <brettlee.lustre at gmail.com> wrote:
>
> Hi.  In what I thought was a valid test, I was unable to confirm that a
> backup and restore retained the layouts.  Perhaps my expectation or process
> was incorrect?  The process was:
>
> 1.  Create 4 files, each with different stripe sizes and stripe counts
> (verified with getstripe).
> 2.  Back up the files using tar-1.26-31.el7.x86_64.
> 3.  Recreate a file system and restore the files.
>
> Backup command:  tar --xattrs -zcvf /scratch.tgz /scratch
> Restore command:  tar zxvf /scratch.tgz
>
> After restoration, getstripe showed that each file had the default stripe
> count (1) and stripe size (1MB).
> FWIW:  After restoring, getfattr produced the same result for each file:
> # getfattr -d -m - -R <file>
> lustre.lov=0s0AvRCwEAAAAdAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAFAAAAAAAAAAAAAA
> AAAAAAAAAAAAAAAAA=
> trusted.link=0s3/HqEQEAAAAuAAAAAAAAAAAAAAAAAAAA
> ABYAAAACAAAEAAAAAAUAAAAAMS5kZA==
> trusted.lma=0sAAAAAAAAAAAABAAAAgAAAB0AAAAAAAAA
> trusted.lov=0s0AvRCwEAAAAdAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAFAAAAAAAAAAAAAA
> AAAAAAAAAAAAAAAAA=
>
> Brett
> --
> Protect Yourself Against Cybercrime
> PDS Software Solutions LLC
> https://www.TrustPDS.com <https://www.trustpds.com/>
>
> On Wed, Mar 15, 2017 at 5:03 AM, Dilger, Andreas <andreas.dilger at intel.com
> > wrote:
>
>> I believe Zmanda is already using GNU tar (or RHEL tar) for the actual
>> backup storage?  I that case it should already work, since we fixed tar
>> long ago to backup and restore xattrs in a way that preserves Lustre
>> layouts.
>>
>> Cheers, Andreas
>>
>> On Mar 14, 2017, at 15:47, Brett Lee <brettlee.lustre at gmail.com> wrote:
>>
>> Thanks for the details, Andreas!
>>
>> Maybe OpenSFS can fund Zmanda so that their backup software can include
>> the Lustre metadata... :)
>>
>> Brett
>> --
>> Protect Yourself Against Cybercrime
>> PDS Software Solutions LLC
>> https://www.TrustPDS.com <https://www.trustpds.com/>
>>
>> On Tue, Mar 14, 2017 at 3:13 PM, Dilger, Andreas <
>> andreas.dilger at intel.com> wrote:
>>
>>> To reply to this old thread, there are two different kinds of Lustre
>>> backup solutions:
>>> - file level backups that traverse the client POSIX filesystem, for
>>> which any number of
>>>   commercial solutions exist.  Making these solutions "capable of saving
>>> Lustre metadata"
>>>   boils down to two simple things - save the "lustre.lov" xattr during
>>> backup (at a minimum,
>>>   other xattrs also should be backed up), and then using mknod(2) +
>>> setxattr() to restore
>>>   the "lustre.lov" xattr before opening the file and restoring the data.
>>>
>>> - device level backups (e.g. "dd" for ldiskfs, and "zfs send/recv" for
>>> ZFS).
>>>
>>> Using the file level backups allows backup/restore of subsets of the
>>> filesystem, since many
>>> HPC sites have Lustre filesystems that are too large to backup
>>> completely.  I typically do
>>> not recommend to use device-level backups for the OSTs, unless doing an
>>> OST hardware migration,
>>> and even then it is probably less disruptive to do Lustre-level file
>>> migration off the OST
>>> before swapping it out.
>>>
>>> Whether file level backups are used or not, I would recommend sites
>>> always make periodic
>>> device level backups of the MDT(s).  The amount of space needed for an
>>> MDT backup is small
>>> compared to the rest of the filesystem (e.g. a few TB at most), and can
>>> avoid the need for
>>> a full filesystem restore (e.g. multi-PB of data, if a full backup
>>> exists at all) even
>>> though all the data is still available on the OSTs.
>>>
>>> The MDT device-level backup can use relatively slow SATA drives, since
>>> they will mostly be
>>> used for linear writes (or occasionally linear reads for restore), so a
>>> few multi-TB SATA III
>>> drives is sufficient for storing a rotating set of MDT device backups.
>>> At 150MB/s for even
>>> a single SATA drive, this is about 2h/TB, which is reasonable to do once
>>> a week (or more often
>>> for smaller MDTs).
>>>
>>> While using an LVM snapshot of the ldiskfs MDT for the backup source is
>>> desirable for consistency
>>> reasons, having even an MDT backup from a mounted and in-use MDT is
>>> better than nothing at
>>> all when a problem is hit, since e2fsck can repair the in-use
>>> inconsistencies fairly easily,
>>> and Lustre can deal with inconsistencies between the MDT and OST
>>> reasonably (at most returning
>>> an -ENOENT error to the client for files that were deleted).
>>>
>>> Cheers, Andreas
>>>
>>> On Feb 7, 2017, at 12:32, Andrew Holway <andrew.holway at gmail.com> wrote:
>>> >
>>> > Would it be difficult to suspend IO and snapshot all the nodes
>>> (assuming ZFS). Could you be sure that your MDS and OSS are synchronised?
>>> >
>>> > On 7 February 2017 at 19:52, Mike Selway <mselway at cray.com> wrote:
>>> >> Hello Brett,
>>> >>
>>> >>                Actually, looking for someone who uses a
>>> commercialized approach (that retains user metadata and Lustre extended
>>> metadata) and not specifically the manual approaches of Chapter 17.
>>> >>
>>> >> Thanks!
>>> >> Mike
>>> >>
>>> >> Mike Selway | Sr. Tiered Storage Architect | Cray Inc.
>>> >> Work +1-301-332-4116 | mselway at cray.com
>>> >> 146 Castlemaine Ct,   Castle Rock,  CO  80104 | www.cray.com
>>> >>
>>> >>
>>> >>> From: Brett Lee [mailto:brettlee.lustre at gmail.com]
>>> >>> Sent: Monday, February 06, 2017 11:45 AM
>>> >>> To: Mike Selway <mselway at cray.com>
>>> >>> Cc: lustre-discuss at lists.lustre.org
>>> >>> Subject: Re: [lustre-discuss] Backup software for Lustre
>>> >>>
>>> >>> Hey Mike,
>>> >>>
>>> >>> "Chapter 17" and
>>> >>> http://www.intel.com/content/www/us/en/lustre/backup-and-res
>>> tore-training.html
>>> >>>
>>> >>> both contain methods to backup & restore the entire Lustre file
>>> system.
>>> >>>
>>> >>> Are you looking for a solution that backs up only the (user) data
>>> files and their associated metadata (e.g. xattrs)?
>>> >>>
>>> >>> Brett
>>> >>> --
>>> >>> Protect Yourself From Cybercrime
>>> >>> PDS Software Solutions LLC
>>> >>> https://www.TrustPDS.com
>>> >>>
>>> >>>> On Mon, Feb 6, 2017 at 11:12 AM, Mike Selway <mselway at cray.com>
>>> wrote:
>>> >>>>
>>> >>>> Hello,
>>> >>>>          Anyone aware of and/or using a Backup software package to
>>> protect their LFS environment (not referring to the tools/scripts suggested
>>> in Chapter 17).
>>> >>>>
>>> >>>> Regards,
>>> >>>> Mike
>>>
>>> Cheers, Andreas
>>> --
>>> Andreas Dilger
>>> Lustre Principal Architect
>>> Intel Corporation
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> lustre-discuss mailing list
>>> lustre-discuss at lists.lustre.org
>>> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
>>>
>>
>>
>
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