Hello btrfs gurus,
Has this ever been considered to implement a feature so that metadata
chunks would always be allocated on a given set of disks part of the btrfs
filesystem?
As metadata use can be intensive and some operations are known to be slow
(such as backref walking), I'm under the (maybe wrong) impression that
having a set of small ssd's just for the metadata would give quite a boost
to a filesystem. Maybe even make qgroups more usable with volumes having 10
snapshots?
This could just be a preference set on the allocator, so that a 6 disks
raid1 FS with 4 spinning disks and 2 ssds prefer to allocate metadata on
the ssd than on the slow drives (and falling back to spinning disks if ssds
are full, with the possibility to rebalance later).
Would such a feature make sense?
--
Stephane.
