On Dec 12, 2013, at 6:39 AM, Martin <[email protected]> wrote: > Some time back, I noticed that with a two HDD btrfs raid1, some tasks > suffered ALL the IO getting choked onto just one HDD! > > > That turned out to be a feature of the btrfs code whereby a device is > chosen depending on the process ID.
I wonder how much btrfs parallelism is affected by the default CFQ scheduler? On the XFS FAQ "the default i/o scheduler, CFQ, will defeat much of the parallelization in XFS." There's also quite a bit of parallelization in Btrfs so it too may be affected, in particular multiple device scenarios. Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
