对于客户端和主机,选择的文件系统变为EXT4.最近,我使用了BTRFS提供的一些非常棒的快照功能来设置具有增量备份的备份服务器.
一些研究提供了一个从未使用BTRFS用于KVM主机的线索,因为FS的碎片会降低客户端的速度,直到它们最终冻结为止.
在KVM客户端上使用BTRFS是否有任何建议/做/不做？
我们正在重新考虑客户和主机的FS选择,
使用XFS而不是EXT4(客户端/主机或仅单面)有什么优势？
解决方法
看一下这个：ZFS,BTRFS,XFS,EXT4 and LVM with KVM – a storage performance comparison
根据作者Gionatan Danti的说法：
The tested scenarios are:
1) Qcow2 backend on top of XFS filesystem on top of a raw MD device. Both thin and partial (Metadata only) preallocation modes were benchmarked;
2) Logical Volumes backend,both in classical LVM (fat preallocation) and thin (thin lvm target) modes. Moreover,thin lvm was analized with both zeroing on and off;
3) raw images on XFS and EXT4 on top of classical LVM,relaying on filesystem sparse-file support for thin provisioning;
4) raw images on XFS and EXT4 on top of thin LVM,relaying on thin lvm target for thin provisioning. In this case,LVM zeroing was disabled as the to-be-zero blocks are directly managed inside the filesystem structures;
5) raw images BTRFS on top of its mirror+stripe implementation (no MD here). I benchmarked BTRFS with CoW both enabled and disabled (nodatacow mount option)
6) raw images ZFS on top of its mirror+stripe implementation (no MD again)
他的结论是：
For VMs storage,stay well away from BTRFS: not only it is marked a “Tech Preview” from RedHat (read: not 100% production ready),but it is very slow when used as a VM images store.
另一篇关于BTRFS的博客,你可以在很多论坛上看到,需要禁用Copy On Write(COW)以获得更好的KVM性能.
Chris Irwin谈论BTRFS的好处并谈论另一种选择：
There are other tools,or you could roll your own cron-job.
So what about ZFS?
I thought ZFS did all these things?Yes,it does
Why not just use ZFS?Go ahead
知道它是否可以使用的另一种方法是自己测试性能是否良好以及它是否可靠而没有写入副本.
如果BTRFS不是最适合您的,您可以尝试ZFS.你有相同的备份功能和许多其他改进,但在linux中实现有点棘手.
