On 17 Aug. 2017 13:22, "Russell Coker via luv-main" <luv-main@luv.asn.au> wrote: On Wednesday, 16 August 2017 11:12:06 AM AEST Rick Moen via luv-main wrote:
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.
Last time I checked XFS had no support for reducing the size of a filesystem. 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). Both XFS and btrfs enthusiastically like to silently throw any data written in the past 5 days on the floor when there's a power failure/kernel panic, so there's that commonality.