Is there a "nossd" option ?

Hi,

Running a 3.19 Ubuntu kernel,

I'm currently budling a RAID-1 BTRFS set for which every underlying device is a LUKS-encrypted device itself built out of a bcache device comprised of a mechanical HD partition + an SSD cache partition.

Looks like it's working.

BUT I see that BTRFS decides by itself to mount with the "ssd" option as bcache makes it think the device is not "rotational".

However I feel that a mechanical HD plus SSD bcache should probably not be "SSD-optimized" as the underlying storage is indeed mechanical and bcache already manages the SSD part optimization by itself - and I'm afraid the "SSD optimization" could actually cause the mechanical storage to end up being much more fragmented than it should...

So the question is : Is there a mount option such as "nossd" that I could use to inhibit the automatic SSD "choice" that BTRFS makes ?

Yes the "nossd" option (written literally like that) does in fact exist. It would have taken you less time to try if it works, than to write this long-winded message. :)

Quoted 4 lines · Le dimanche 21 juin 2015 22:31:21 Roman Mamedov a écrit :

Yes the "nossd" option (written literally like that) does in fact exist. It would have taken you less time to try if it works, than to write this long-winded message. :)

Possibly. Unless trying a non-existing mount option causes the mount to fail, thus causing the system boot to fail, thus needing me to boot from a live rescue CD... that would take much longer than writing an half-page email ;-)

Quoted 4 lines · Le dimanche 21 juin 2015 22:31:21 Roman Mamedov a écrit :

Yes the "nossd" option (written literally like that) does in fact exist. It would have taken you less time to try if it works, than to write this long-winded message. :)

Possibly. Unless trying a non-existing mount option causes the mount to fail, thus causing the system boot to fail, thus needing me to boot from a live rescue CD... that would take much longer than writing an half-page email ;-)