Date: Wed, 5 Jun 2013 15:16:36 -0700 From: Jeremy Chadwick <jdc@koitsu.org> To: Dmitry Morozovsky <marck@rinet.ru> Cc: freebsd-stable@FreeBSD.org Subject: Re: TRIM support through ciss Message-ID: <20130605221636.GA21946@icarus.home.lan> In-Reply-To: <alpine.BSF.2.00.1306060157240.48048@woozle.rinet.ru> References: <alpine.BSF.2.00.1306060157240.48048@woozle.rinet.ru>
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On Thu, Jun 06, 2013 at 02:00:36AM +0400, Dmitry Morozovsky wrote: > Dear colleagues, > > I have a DB server with ciss and a bunch of disks (8 SAS + 2 Intel SATA SSD). > > However, this setup does not seem to support TRIM on SSDs: > > kstat.zfs.misc.zio_trim.bytes: 0 > kstat.zfs.misc.zio_trim.success: 0 > kstat.zfs.misc.zio_trim.unsupported: 418 > kstat.zfs.misc.zio_trim.failed: 0 > > > Excerpt from dmesg about SSD: > > da9 at ciss0 bus 0 scbus0 target 9 lun 0 > da9: <COMPAQ RAID 0 OK> Fixed Direct Access SCSI-5 device > da9: Serial Number PACCR9SZ7KJS > da9: 135.168MB/s transfers > da9: Command Queueing enabled > da9: 114439MB (234371520 512 byte sectors: 255H 32S/T 28722C) > da9: quirks=0x1<NO_SYNC_CACHE> > da9: Delete methods: <NONE(*)> > > the last line bothers me... > > Is there any tuning I missed? I'm sure Steve will respond, but in the meantime... I assume this is you running stable/9 with r251419 or newer (which just got committed a few hours ago)? I haven't looked at the code, but it is very, VERY important to remember that you are *always* at the whim of 1) the controller driver (ciss(4) in this case), and 2) the controller firmware, as to whether or not certain pass-through commands are supported (in this case, since you have a SAS controller, this would be accomplished via a SCSI command that your controller does not support. Oh, it looks like Steve just replied and said more or less what I did. :-) Bottom line as "we" (the royal we, I guess) have been saying for many years now: any controller which operates in a RAID fashion and does not support "true JBOD" (meaning the controller acts a generic controller with no concept of RAID), will almost always get in the way. Instead, stick with true non-RAID controllers -- and yes I am aware choices are limited. -- | Jeremy Chadwick jdc@koitsu.org | | UNIX Systems Administrator http://jdc.koitsu.org/ | | Making life hard for others since 1977. PGP 4BD6C0CB |
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