XFS reflink - production use?

In https://blogs.oracle.com/linux/xfs-data-block-sharing-reflink I just read, that
"I'm pleased to announce with xfsprogs 5.1, the reflink feature is now production ready and enabled by default on new installations, having graduated from the experimental and stabilization phases"
I was a little disappointed to find out that even SLES15 SP2 only has xfsprogs-4.15.0-4.27.1.x86_64.
So my question is:
Is the version 5.1 of xfsprogs about to be available soon in latest editions of SLES12 / SLES15?
Who has production experiences in using the XFS reflink feature to share here (probably in conjunction with disk backup)?
Kind regards, Tom


  • AndreasAndreas Senior Member
    edited October 22

    Please read "SUSE Linux Enterprise Server 15 SP2 release notes" for more information about XFS reflink support in SUSE Linux Enterprise.
    Try out XFS reflink with # cp --reflink=always (see # man cp) and # filefrag -v :
    There are no more EXPERIMENTAL warnings in SLED 15 SP2 for the usage of XFS reflink. So XFS reflink could consider as stable.
    Be warned that xfsdump is not "XFS reflink aware". In case of a under heavy xfs reflink usage standing xfs partition, xfsdump produce dump/backup files which are significantly larger as the used storage place on this xfs partition.
    Try out XFS reflink in daily usage: Create a home partition with # mkfs.xfs -m reflink=1 and put the attached shell script under /usr/local/bin/createSnaphotHourly.sh (=> don't forget to change file name extension and don't forget the command # chmod u=rwx,g=rx o=rx /usr/local/bin/createSnapshotHourly.sh). Activate this shell script hourly by a crontab entry:
    # su
    # crontab -u foo -e
    # Snapshot erstellen
    5 * * * * /usr/local/bin/createSnapshotHourly.sh
    The attached shell script take use of the "NO DUMP" attribute. Please read # man xfsdump, chaptre "Excluding individual files" for more information about the "NO DUMP" attribute. You can see all files with "NO DUMP" attribute with:

    lsattr -laR ~/ | grep No_Dump

    Have a lot of fun with XFS reflink!

  • AndreasAndreas Senior Member

    For more general information about SLE rescue mode and XFS partition handling (=> mkfs.xfs, xfs_repair, xfsdump and xfsrestore) see:

  • swadmswadm Established Member

    Andreas, thanks! So to summarize your statement, while https://www.suse.com/releasenotes/x86_64/SUSE-SLED/15/ mentions that "Reflink Feature of XFS Is Not Supported" (2.6.1), this is not the case for https://www.suse.com/releasenotes/x86_64/SUSE-SLED/15-SP2/, and we should be able to trust the reflink feature on XFS filesystems.

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