Best filesystem to use under RHEL/Centos 7.5?

although the RHEL environment is not very friendly for urbackup server, we still want to use it if possible. currently we are using btrfs for urbackup. since RHEL 7.4 the btrfs filesystem is broken with default kernel. but after replacing the kernel, urbackup is still working fine.

now RHEL 7.5 comes. btrfs is still broken. but in RHEL 7.5 there is a new storage object called VDO (Virtual Data Optimizer). this object can do three things behind the scene: zero-block elimination, data deduplication, and data compression.

I haven’t test that. but I want to know in theory can VDO comparable to btrfs under urbackup? urbackup can do snapshot directly to btrfs, but I don’t know if this is a big advantage when VDO can do data-dedupe behind the scene.

sorry I don’t really understand how urbackup works at server side. thanks a lot for advice, even just in theory.


Using the snapshot thing in btrfs, urbackup doesn’t need to count links and whatnot.
I havent tested it, but that should result in much fatser backups (thats how it has been reported by thoses that tested it).

Anyhow, try and report :slight_smile:

me too

That VDO thing looks cool. Though it seems you have to be careful about setting the compression ratio and dedup ratio such that the actually used space doesn’t get larger than the available space. In connection with UrBackup one can probably monitor the acutally used space and run cleanups with appropriate sizes if necessary.
In connection with XFS reflinking Xfs reflink support in soon to come v2.2.1? that would give the same features as btrfs except for the data integrity/scrubbing.

Hi uroni:

so you also think VDO+xfs maybe a good partner for urbackup? I will try that when scientific linux 7.5 come out. and could you tell me what version will support xfs reflink?

Looks like it. Except for the whole bit rot thing…

Before Linux kernel 4.15 or so XFS reflinking was declared experimental, so it probably isn’t in RHEL 7 (maybe RHEL 8…).

Hi uroni:

I think RedHat may backport the xfs feature to RHEL7 as they usually do. or I can just use newer kernel by myself. but which urbackup version will support xfs reflink? will current version like 2.2.11 works, or I should wait for 2.3.x ?