ssd for zfs

[Richard Kojedzinszky]

Dear,

I also have a separate cache device for the pool. Thanks. I would like to 
use this only for log.

Regards,

Kojedzinszky Richard

On Mon, 2 Dec 2013, krad wrote:

> you also want to look at your workloads on the pool, if you are not doing lots of async writes, you may well be better off using it as an l2arc device. Ideally you should have separate devices, but you could partition the ssd and use
> it as l2arc and zill, but that isnt best practice, but there are many people who do that out there with varying mileage depending on their workloads.
> 
> 
> On 28 November 2013 12:51, Steven Hartland <killing at multiplay.co.uk> wrote:
>       FreeBSD has TRIM support and some disks have very slow TRIM support.
>
>       Try disabling TRIM support in /boot/loader.conf
>       vfs.zfs.trim.enabled=0
>
>       Also check to see if your seeing ashift 12 as I suspect thats actually
>       a 4k not 512b device. This can be confirmed by looking at the boot
>       output.
>
>          Regards
>          Steve
>       ----- Original Message ----- From: "Richard Kojedzinszky" <krichy at cflinux.hu>
>       To: <freebsd-fs at freebsd.org>
>       Sent: Wednesday, November 27, 2013 8:51 AM
>       Subject: ssd for zfs
> 
>
>             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 at freebsd.org mailing list
>             http://lists.freebsd.org/mailman/listinfo/freebsd-fs
>             To unsubscribe, send any mail to "freebsd-fs-unsubscribe at freebsd.org"
> 
> 
> ================================================
> This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise
> disseminating it or any information contained in it.
> In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337
> or return the E.mail to postmaster at multiplay.co.uk.
> 
> _______________________________________________
> freebsd-fs at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-fs
> To unsubscribe, send any mail to "freebsd-fs-unsubscribe at freebsd.org"
> 
> 
> 
>