Date: Wed, 27 Nov 2013 06:20:58 -0600 From: Chuck Burns <break19@gmail.com> To: freebsd-fs@freebsd.org Subject: Re: ssd for zfs Message-ID: <1464424.7QQFLu4g0t@blackbeast.local> In-Reply-To: <alpine.BSF.2.00.1311270946260.70091@pi.nmdps.net>
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On Wednesday, November 27, 2013 9:51:06 AM Richard Kojedzinszky wrote: > Dear fs developers, > > Probably this is not the best list to report my issue, but please forward > it to where it should get. > > I bought an SSD for my ZFS filesystem to use it as a ZIL. I've tested it > under linux, and found that it can handle around 1400 random synchronized > write IOPS. Then I placed it into my freebsd 9.2 box, and after attaching > it as a ZIL, my zpool only performs 100 (!) write iops. I've attached it > to an AHCI controller and to an LSI 1068 controller, on both it behaves > the same. So I expect that something in the scsi layer is different, > FreeBSD is handling this device slower, but actually it can handle the > 1400 iops as tested under linux. > > Please give some advice where to go, how to debug, and how to improve > FreeBSD's performance with this drive. > > The device is: > # camcontrol identify ada3 > pass4: <STEC MACH16 M16SD2S-50UI 00000299> ATA-8 SATA 2.x device > pass4: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 512bytes) > > protocol ATA/ATAPI-8 SATA 2.x > device model STEC MACH16 M16SD2S-50UI > firmware revision 00000299 > serial number STM0001680E8 > WWN 5000a7203006f8e5 > media serial number STEC MACH16 M16SD2S-50UI STM00 > cylinders 16383 > heads 15 > sectors/track 63 > sector size logical 512, physical 512, offset 0 > LBA supported 97696368 sectors > LBA48 supported 97696368 sectors > PIO supported PIO4 > DMA supported WDMA2 UDMA6 > media RPM non-rotating > > Feature Support Enabled Value Vendor > read ahead yes yes > write cache yes yes > flush cache yes yes > overlap no > Tagged Command Queuing (TCQ) no no > Native Command Queuing (NCQ) yes 32 tags > SMART yes yes > microcode download yes yes > security yes no > power management yes yes > advanced power management no no > automatic acoustic management no no > media status notification no no > power-up in Standby yes no > write-read-verify no no > unload no yes > free-fall no no > Data Set Management (DSM/TRIM) yes > DSM - max 512byte blocks yes 8 > DSM - deterministic read yes any value > Host Protected Area (HPA) yes no 97696368/97696368 > HPA - Security no > > Regards, > > Kojedzinszky Richard > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" So.. You tested the speed of the ZIL device, and it's fast.. But you're complaining about the speed of the zpool? We can't give you any information, because a ZIL is not the only thing in a zpool. Are the rest of your drives SSDs, or are they mechanical drives? Are they AHCI? Or SAS? Your actual storage devices are likely what is slow here. break19home | help
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