On Wednesday, 16 August 2017 11:12:06 AM AEST Rick Moen via luv-main wrote:Last time I checked XFS had no support for reducing the size of a filesystem.
> Maybe Stratis after interim use of XFS.
> https://www.phoronix.com/scan.php?page=news_item&px=Stratis- Red-Hat-Project
> https://stratis-storage.github.io/StratisSoftwareDesign.pdf
>
> It's funny seeing XFS make a resurgence. I used it on Debian back
> before ext3 had become mainstream. At the time, it seemed solid
> technology but its Linux future was (then) in doubt because it was a
> huge patchset.
ZFS also has no support for that so it's not necessarily a huge problem. But
if Stratis is going to use multiple XFS filesystems to compare with the
multiple ZFS mount points or BTRFS subvols then it will be a massive problem.
Stratis is aiming for a version 1.0 release next year, and version 3.0 is
aimed at having ZFS feature parity. That's not good for all the people who
need ZFS features today!
XFS has no support for checksums that compares to ZFS and BTRFS. To do it
properly you need to do it in the filesystem. I guess that Stratis could use
DM to have a checksum layer but there would be some overheads in trying to do
it that way if you also want to deal with missing writes. Another option is
to change XFS to have checksums, but that would be a huge change (fixing
whatever problems they apparently have with BTRFS would be easier).