On 14/02/12 17:31, Avi Miller wrote:
On 14/02/2012, at 5:23 PM, Toby Corkindale wrote:
Like, / is RAID1 and /boot is RAID1 but /usr is RAID5, all within one big "blob" of btrfsness.
[..snip..]
And if the feature exists, why isn't it mentioned on the wiki page, man pages, etc?
The feature doesn't exist yet: it's one of the things to be pulled in by Chris after he delivers the btrfsck code. But yes, the plan is for btrfs to allow for multiple RAID levels within a single filesystem and to use the existing balancer code to be able to restripe between RAID levels, not just for an entire filesystem, but for subvolumes and files.
Ah OK. That would explain why I was unable to find the feature even on up to date kernels and git versions of the tools!
Note that the restripe functionality was merged into Chris' tree about a week ago, so it's brand-new. There is a lot going into btrfs and I suspect more happening in the code than on the wiki.
I have noticed that Debian and Ubuntu ship terribly old versions of the btrfs userspace tools -- I had to build my own just to get access to the "Scrub" feature which has been around for a while. That's a pity :(