On 17/05/14 18:07, Neil Bothwick wrote: > On Sat, 17 May 2014 08:08:17 +0800, William Kenworthy wrote: > >> Don't forget to have a maintenance program - run a scrub regularly once >> a week or so - I have enough btrfs drives (22 qemu files, 4 WD Greens >> att) to see about one or two scrub fixable errors a week with no obvious >> cause, sometimes serious (in a critical file). > > That's a bit scary. I'm running ZFS on several systems, scrub twice a > week and have never seen any corruption. Do you think this is because of > btrfs, your hardware or your usage? > >
Usage and bugs in btrfs - the backup drive is using dirvish which hammers the drive quite hard as its uses hardlinks for duplicate files (faster, saves space). Reiserfs which I used to use (same hardware) only ever got an error whih a cause like power outage in the middle of a backup - easily recovered if time consuming. Its also on an LVM running across a mixture of drives raging from an old ide to WD green. Part of the reason for converting it to btrfs is because if it survives the hammering (and its getting better), its a sign its getting robust. I did try ext 4 (twice) before reiserfs - both attempts lasted around a week. All this is on roughly the same hardware - Ive had a couple of disks fail, and move partitions around on the LVM as necessary. The motherboard is an old core2 but running 32bit. Kernels are all 3.12.13 gentoo-sources. For the VM's, they were still getting an occasional error when I had them on a reiserfs storage. I tried ceph on btrfs for awhile but not having enough hardware to do it properly (mostly btrfs failures it must be said) its now on a 3 disk btrfs raid1. Since creating that one just a few weeks ago I have not seen an error, though btrfs VM's stored on it have had errors. The VM's 10-12 gentoo, 3xwin (usually 6 running, not all 15 or so running at the same time) use a supermicro motherboard, dual quad zeons and 16G ram. BillK
