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All of my production systems use XFS for the last 5-10 years. I never liked the idea that we have 5 filesystems on Linux an you have to know which is better for
by istvan__ 11y ago
All of my production systems use XFS for the last 5-10 years. I never liked the idea that we have 5 filesystems on Linux an you have to know which is better for your use case, while other Unix like systems offer you maybe 2 options but there is one that is supported and recommended (like ZFS on Solaris). I think ext4 does not offer too much for the most of the users over ext3 but given its history (lots of data loss scenarios) I would not want to risk it to start to use it in production. On the top of that, the recent moves from CentOS to use XFS as the default FS just makes me think I made the right decision 10 years ago to use XFS for almost everything I do.
Ted Tso about ext4:
> P.S. It's bugs like these which is why I'm always amused by people
> who think that just because a file system is safely being used by
> their developers, that it's safe to throw production workloads on
> them.
- kasabali 11y agoXFS doesn't have an impressive track record when it comes to data loss, either. Come on people, every filesystem with large number of users has had their screw-ups.
- istvan__ 11y agoWell I am not sure about that, as anecdotal evidence, most systems engineers I know use XFS as default on their systems. This might be coincidence, but I think it is just a sign that XFS has less "screw-ups" than ext3/4. A representative survey would help to prove it.
- AceJohnny2 11y agoWell, if we're going by anecdotal evidence, I've had a big loss when an XFS-on-RAID system had a power failure about 4 years ago, and recently I know someone who's lost hundreds of gigs to XFS as well, with no power loss that he's aware of. So there.
- rodgerd 11y agoTrue. I am not, however, aware of the XFS developers ever deliberately changing the behaviour of an older version of XFS to make it less safe to match the data corruption problems in a newer version.
- velodrome 11y agoWell, I don't know about reliability* but there are many other reasons to choose XFS: 1) Support for large volumes: 8EB vs 16TB (Ext4) 2) Support for large file sizes: 1EB vs 16TB (Ext4) 3) Support for large number of subfolders: Ext3 has a 32k subfolder limit 4) Online defrag support (supported in Ext4) For us, we had to use XFS for MySQL multi-tenent applications. * XFS had corruption issues back in the day with specific kernels (2.6.9, that's the one I remember).
- istvan__ 11y agoThank you, #1 might be the biggest reason that XFS is used over ext4 I guess, 16TB is not as unusual size for a decent raid array nowadays. I would like to understand why CentOS (and I guess RedHat went for XFS) though.
- edgan 11y agoExt4 does support larger than 16tb filesystems. df -h | grep md127 ; mount | grep md127 /dev/md127 26T 14T 12T 55% /home/data /dev/md127 on /home/data type ext4 (rw,relatime,stripe=1792,data=ordered) Ext3 was 32k, but ext4 is 65k subfolder limit. I have run into this one before. The real solution is to do directory hashing when you get this crazy with tons of subfolders.
- istvan__ 11y agoI think there is a difference between what is supported and what is possible. https://access.redhat.com/solutions/1532 https://access.redhat.com/solutions/1532
- simoncion 11y agoRedHat has tested EXT4 on partitions larger than 16TB. From your linked note: "EXT4 [on RHEL7] [Cerfified max FS size:] 50TB [Theoretical max FS size:] (1EB)" Moreover, RedHat's lack of Enterprise Support for a configuration doesn't mean that that configuration is a bad idea, or is doomed to failure. :)