* MD and rotational attribute @ 2012-02-20 12:20 Karel Zak [not found] ` <20120227104230.125cb9e2@notabene.brown> 0 siblings, 1 reply; 3+ messages in thread From: Karel Zak @ 2012-02-20 12:20 UTC (permalink / raw) To: Neil Brown; +Cc: linux-kernel, linux-raid Hi Neil, I guess that something is wrong with MD. If you create a RAID on ssd (or scsi_debug in my example) than MD device is reported as rotational. Simple example: modprobe scsi_debug dev_size_mb=500 fdisk /dev/sdb ... mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb{1,2} # cat /sys/block/sdb/queue/rotational 0 # cat /sys/block/md0/queue/rotational 1 It seems like a bug. Karel -- Karel Zak <kzak@redhat.com> http://karelzak.blogspot.com ^ permalink raw reply [flat|nested] 3+ messages in thread
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* Re: MD and rotational attribute [not found] ` <20120227104230.125cb9e2@notabene.brown> @ 2012-02-27 0:18 ` Martin K. Petersen 2012-02-27 0:40 ` NeilBrown 0 siblings, 1 reply; 3+ messages in thread From: Martin K. Petersen @ 2012-02-27 0:18 UTC (permalink / raw) To: NeilBrown; +Cc: Karel Zak, linux-kernel, linux-raid, Martin K.Petersen >>>>> "Neil" == NeilBrown <neilb@suse.de> writes: Neil, Neil> (I would say that the name 'rotational' is a bug - the issues here Neil> is really whether seek is fast or slow is it not??... but no Neil> matter). Both the ATA and SCSI specs use the term 'rotational' which I guess is how we ended up with that name. Neil> What do you think Martin? Should QUEUE_FLAG_NONROT move to Neil> queue_limits much like QUEUE_FLAG_CLUSTER did? Absolutely. I posted some patches converting both the nonrot and discard/secure discard queue flags a while back but they didn't go in. I'll freshen up the kit and resend... -- Martin K. Petersen Oracle Linux Engineering ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: MD and rotational attribute 2012-02-27 0:18 ` Martin K. Petersen @ 2012-02-27 0:40 ` NeilBrown 0 siblings, 0 replies; 3+ messages in thread From: NeilBrown @ 2012-02-27 0:40 UTC (permalink / raw) To: Martin K. Petersen; +Cc: Karel Zak, linux-kernel, linux-raid [-- Attachment #1: Type: text/plain, Size: 792 bytes --] On Sun, 26 Feb 2012 19:18:12 -0500 "Martin K. Petersen" <martin.petersen@oracle.com> wrote: > >>>>> "Neil" == NeilBrown <neilb@suse.de> writes: > > Neil, > > Neil> (I would say that the name 'rotational' is a bug - the issues here > Neil> is really whether seek is fast or slow is it not??... but no > Neil> matter). > > Both the ATA and SCSI specs use the term 'rotational' which I guess is > how we ended up with that name. > > > Neil> What do you think Martin? Should QUEUE_FLAG_NONROT move to > Neil> queue_limits much like QUEUE_FLAG_CLUSTER did? > > Absolutely. I posted some patches converting both the nonrot and > discard/secure discard queue flags a while back but they didn't go > in. I'll freshen up the kit and resend... > Thanks! NeilBrown [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 828 bytes --] ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-02-27 0:41 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2012-02-20 12:20 MD and rotational attribute Karel Zak [not found] ` <20120227104230.125cb9e2@notabene.brown> 2012-02-27 0:18 ` Martin K. Petersen 2012-02-27 0:40 ` NeilBrown
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