<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Thu, Oct 30, 2014 at 12:54 PM, B.S. <span dir="ltr"><<a href="mailto:bs27975@yahoo.ca" target="_blank">bs27975@yahoo.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I suppose there'd be a performance hit with btrfs checksummed over snapshots, but presumably also less complexity, let alone more timely alert of any hardware issue. (?)<br></blockquote><div><br></div><div>You don't want to store your VMs on BTRFS. They actually specifically say not to, as you'll cause significant fragmentation. Currently their defrag method can cause problems with snapshots, I believe.<br><br></div><div>You can disable COW for your VM directory, which will solve fragmentation. However, it will also negate the benefits of BTRFS in the first place (checksums, snapshots, etc). I've still got my "legacy" LVM disk for VM storage because I can just snapshot the whole filesystem, and either cp, rsync, or dump the contents.<br></div><div><br></div><div>To meet my goal of as few extra filesystems as possible, I'm trying to convert my VMs to have NFS root filesystems, which can be exported from my NAS, and thus benefit from the BTRFS there. I haven't had success yet, though.<br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
In poking about, it seemed that such a mirror becomes self-healing. A spot goes bad, checksum fails, things get recopied. Interesting.<br></blockquote><div><br></div><div>That's why I'm using BTRFS -- checksums and recovery. It's also why I run a weekly scrub before my snapshot and backup.<br><br>ZFS is another option, possibly more stable. However, I wanted to stay in-tree, especially since my server doesn't have a display connector, so I'll be blind-booting USB media if I ever have a fail to boot situation. (or looking for a spare graphics adapter, I guess).<br><br></div></div>-- <br><div dir="ltr">Chris Irwin<br><<a href="mailto:chris@chrisirwin.ca" target="_blank">chris@chrisirwin.ca</a>></div>
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