Re: Is there a nossd option ?
On Sun, 21 Jun 2015 19:13:10 +0200 Swâmi Petaramesh sw...@petaramesh.org wrote: 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. :) -- With respect, Roman signature.asc Description: PGP signature
Re: Is there a nossd option ?
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 ;-) Best regards. -- Swâmi Petaramesh sw...@petaramesh.org http://petaramesh.org PGP 9076E32E -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in
Re: Is there a nossd option ?
On Sun, 21 Jun 2015 20:11:25 +0200 Swâmi Petaramesh sw...@petaramesh.org wrote: 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 ;-) mount / -o nossd,remount works too: [3917300.257773] BTRFS info (device dm-0): not using ssd allocation scheme As a side note, I used this option a lot in the past to make remote block devices such as NBD or AoE not detect as SSDs. -- With respect, Roman signature.asc Description: PGP signature
Re: Is there a nossd option ?
On Jun 21, 2015, at 1:11 PM, Swâmi Petaramesh sw...@petaramesh.org wrote:
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 ;-)
Man pages work well too :)
http://manpages.ubuntu.com/manpages/utopic/man8/mount.8.html
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