Re: Oddly slow read performance with near-full largish FS

[Charles Cazabon <charlesc-lists-btrfs@pyropus.ca>]

Austin S Hemmelgarn <ahferroin7@gmail.com> wrote:
>
> This actually sounds kind of like the issues I have sometimes on my
> laptop using btrfs on an SSD, I've mostly resolved them by tuning IO
> scheduler parameters, as the default IO scheduler (the supposedly
> Completely Fair Queue, which was obviously named by a mathematician
> who had never actually run the algorithm) has some pretty brain-dead
> default settings.  The other thing I would suggest looking into
> regarding the variability is tuning the kernel's write-caching
> settings

Ok, that's something I will examine.  I knew CFQ is completely wrong for SSD
use, but I thought it was still one of the better schedulers for spinning
disks.  Apparently that may not be the case.

Thanks,

Charles
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Charles Cazabon
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