I ran a test locally with RHEL 6.8 and the included tar 1.26 using strace, and tar is properly using mknod+setxattr to restore the "lov" xattr, and the stripe count and stripe size to be preserved.
The OST index is not preserved with the xattr restore, since that may cause imbalance if the files were backed up in a different filesystem (e.g. one with fewer OSTs). The MDS will balance OST allocation as needed for the current OST usage. Could you please run your tar on RHEL 7 with strace to see if it is doing this correctly? Cheers, Andreas On Mar 18, 2017, at 21:51, Brett Lee <brettlee.lus...@gmail.com<mailto:brettlee.lus...@gmail.com>> wrote: 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.dil...@intel.com<mailto:andreas.dil...@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.lus...@gmail.com<mailto:brettlee.lus...@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=0s0AvRCwEAAAAdAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAFAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= trusted.link=0s3/HqEQEAAAAuAAAAAAAAAAAAAAAAAAAAABYAAAACAAAEAAAAAAUAAAAAMS5kZA== trusted.lma=0sAAAAAAAAAAAABAAAAgAAAB0AAAAAAAAA trusted.lov=0s0AvRCwEAAAAdAAAAAAAAAAAEAAACAAAAAAAQAAEAAAAFAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= 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.dil...@intel.com<mailto:andreas.dil...@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.lus...@gmail.com<mailto:brettlee.lus...@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.dil...@intel.com<mailto:andreas.dil...@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.hol...@gmail.com<mailto:andrew.hol...@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 > <msel...@cray.com<mailto:msel...@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<tel:%2B1-301-332-4116> | >> msel...@cray.com<mailto:msel...@cray.com> >> 146 Castlemaine Ct, Castle Rock, CO 80104 | >> www.cray.com<http://www.cray.com> >> >> >>> From: Brett Lee >>> [mailto:brettlee.lus...@gmail.com<mailto:brettlee.lus...@gmail.com>] >>> Sent: Monday, February 06, 2017 11:45 AM >>> To: Mike Selway <msel...@cray.com<mailto:msel...@cray.com>> >>> Cc: lustre-discuss@lists.lustre.org<mailto:lustre-discuss@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-restore-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 >>>> <msel...@cray.com<mailto:msel...@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@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
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