I will be putting 4 500GB SATA disks in my Ultra80. I currently have two 10K rpm 73G SCSI disks in it with 10G for the OS (UFS) and the remaining space for a ZFS pool (the two remaining partitions are setup in a mirror). Would it be worth my while to move all the data off of the zfs partitions of the 73G disks and use those partitions for ZIL? Would I really gain any performance from that? -brian -- "Perl can be fast and elegant as much as J2EE can be fast and elegant. In the hands of a skilled artisan, it can and does happen; it''s just that most of the shit out there is built by people who''d be better suited to making sure that my burger is cooked thoroughly." -- Jonathan Patschke
Hello Brian,
Wednesday, December 5, 2007, 9:15:10 PM, you wrote:
BH> I will be putting 4 500GB SATA disks in my Ultra80. I currently have
BH> two 10K rpm 73G SCSI disks in it with 10G for the OS (UFS) and the
BH> remaining space for a ZFS pool (the two remaining partitions are setup
BH> in a mirror).
BH> Would it be worth my while to move all the data off of the zfs partitions
BH> of the 73G disks and use those partitions for ZIL? Would I really gain
BH> any performance from that?
BH> -brian
In a very specific scenario - maybe.
In most cases - I doubt it, I would say you rather loose some
performance.
--
Best regards,
Robert Milkowski mailto:rmilkowski at task.gda.pl
http://milek.blogspot.com
On Wed, 5 Dec 2007, Brian Hechinger wrote:> I will be putting 4 500GB SATA disks in my Ultra80. I currently have > two 10K rpm 73G SCSI disks in it with 10G for the OS (UFS) and the > remaining space for a ZFS pool (the two remaining partitions are setup > in a mirror). > > Would it be worth my while to move all the data off of the zfs partitions > of the 73G disks and use those partitions for ZIL? Would I really gain > any performance from that?Hi Brian, I don''t think you''ll see any worthwhile improvement. For a ZIL device, you really need something like a (small) SAS 15k RPM 3.5" drive - which will sustain 700 to 900 IOPS (my number - open to argument) - or a RAM disk or one of these [1]. 10K RPM SCSI disks will get (best case) 350 to 400 IOPS. Remember, the main issue with legacy SCSI is that (SCSI) commands are sent 8-bits wide at 5Mbits/Sec - for backwards compatibility. You simply can''t send enough commands over a SCSI bus to busy out a modern 10k RPM SCSI drive. BTW, this is easy to verify: just buy the same drive, one with a SCSI interface and one with a SAS (or FC) interface, and in about 5 minutes, you''ll be looking for a victim ^H^H^H^H^H^H buyer for the SCSI drive. PS: LsiLogic just updated their SAS HBAs and have a couple of products very reasonably priced IMHO. Combine that with a (single ?) Fujitsu MAX3xxxRC (where xxx represents the size) and you''ll be wearing a big smile every time you work on a system so equipped. Tell Santa that you want an LsiLogic SAS HBA and some SAS disks for Xmas! :) [1] Finally, someone built a flash SSD that rocks (and they know how fast it is judging by the pricetag): http://www.tomshardware.com/2007/11/21/mtron_ssd_32_gb/ http://www.anandtech.com/storage/showdoc.aspx?i=3167 Regards, Al Hopper Logical Approach Inc, Plano, TX. al at logical-approach.com Voice: 972.379.2133 Fax: 972.379.2134 Timezone: US CDT OpenSolaris Governing Board (OGB) Member - Apr 2005 to Mar 2007 http://www.opensolaris.org/os/community/ogb/ogb_2005-2007/ Graduate from "sugar-coating school"? Sorry - I never attended! :)
On Wed, Dec 05, 2007 at 06:12:18PM -0600, Al Hopper wrote:> > I don''t think you''ll see any worthwhile improvement. For a ZIL > device, you really need something like a (small) SAS 15k RPM 3.5" > drive - which will sustain 700 to 900 IOPS (my number - open to > argument) - or a RAM disk or one of these [1]. > > 10K RPM SCSI disks will get (best case) 350 to 400 IOPS. Remember, > the main issue with legacy SCSI is that (SCSI) commands are sent > 8-bits wide at 5Mbits/Sec - for backwards compatibility. You simply > can''t send enough commands over a SCSI bus to busy out a modern 10k > RPM SCSI drive.Ah, ok then. Thanks for the detailed explanation Al, that was very helpful.> PS: LsiLogic just updated their SAS HBAs and have a couple of products > very reasonably priced IMHO. Combine that with a (single ?) Fujitsu > MAX3xxxRC (where xxx represents the size) and you''ll be wearing a big > smile every time you work on a system so equipped. > > Tell Santa that you want an LsiLogic SAS HBA and some SAS disks for > Xmas! :)Santa came early this year. :) The whole reason I''m able to get these SATA disks into my Ultra80 is because I bought an LSI SAS3080X and 4-lane SAS to 4-sata cable. ;) ($60 including shipping, not a bad deal at all!!) I wasn''t sure what I was going to do with the other 4 channels, for the time being nothing as I''m now completely broke. :) A nice SAS enlosure would be a nice addition to this setup I think. Maybe a couple of those Fujitsu disks would be nice.> [1] Finally, someone built a flash SSD that rocks (and they know how > fast it is judging by the pricetag): > http://www.tomshardware.com/2007/11/21/mtron_ssd_32_gb/ > http://www.anandtech.com/storage/showdoc.aspx?i=3167Uhm, holy crap. I want one of those for my laptop now. I only have a 40G in there, so a 32G mtron would be perfect. ;) Now, the price might be an issue however. ;) -brian -- "Perl can be fast and elegant as much as J2EE can be fast and elegant. In the hands of a skilled artisan, it can and does happen; it''s just that most of the shit out there is built by people who''d be better suited to making sure that my burger is cooked thoroughly." -- Jonathan Patschke
On Wed, Dec 05, 2007 at 06:12:18PM -0600, Al Hopper wrote:> > PS: LsiLogic just updated their SAS HBAs and have a couple of products > very reasonably priced IMHO. Combine that with a (single ?) Fujitsu > MAX3xxxRC (where xxx represents the size) and you''ll be wearing a big > smile every time you work on a system so equipped.Hmmm, on second glace, 36G versions of that seem to be going for $40. Hmmm............... -brian -- "Perl can be fast and elegant as much as J2EE can be fast and elegant. In the hands of a skilled artisan, it can and does happen; it''s just that most of the shit out there is built by people who''d be better suited to making sure that my burger is cooked thoroughly." -- Jonathan Patschke
On 12/6/07, Brian Hechinger <wonko at 4amlunch.net> wrote:> On Wed, Dec 05, 2007 at 06:12:18PM -0600, Al Hopper wrote: > > > > PS: LsiLogic just updated their SAS HBAs and have a couple of products > > very reasonably priced IMHO. Combine that with a (single ?) Fujitsu > > MAX3xxxRC (where xxx represents the size) and you''ll be wearing a big > > smile every time you work on a system so equipped. > > Hmmm, on second glace, 36G versions of that seem to be going for $40.Do you mean $140, or am I missing a really good deal somewhere? Scott
> 10K RPM SCSI disks will get (best case) 350 to 400 IOPS. Remember, > the main issue with legacy SCSI is that (SCSI) commands are sent > 8-bits wide at 5Mbits/Sec - for backwards compatibility.This is true for really old SCSI configurations, but if you''re buying a modern disk and controller (U160/U320), commands are packetized and sent at full rate.> You simply can''t send enough commands over a SCSI bus to busy > out a modern 10k RPM SCSI drive.If you mean ''small sequential i/o requests'', you''re probably true. For random i/o requests, you can pretty easily busy it out, and for large requests, the command overhead is negligible. The bigger advantage of SAS is its point-to-point nature which means that when you have multiple disks there''s no queueing delay at the bus. So I''d agree with your recommendation to prefer SAS to parallel SCSI :-) but would just like to point out that the command-transfer-speed bottleneck was dealt with many years ago (ca. 1999). This message posted from opensolaris.org
> On Wed, 5 Dec 2007, Brian Hechinger wrote:> [1] Finally, someone built a flash SSD that rocks > (and they know how > fast it is judging by the pricetag): > http://www.tomshardware.com/2007/11/21/mtron_ssd_32_gb > / > http://www.anandtech.com/storage/showdoc.aspx?i=3167Great now if only Sun would rebadge these and certify them for use in their products, I''d have some PO''s waiting. This message posted from opensolaris.org
On Thu, Dec 06, 2007 at 03:27:33PM -0800, Scott Laird wrote:> > > MAX3xxxRC (where xxx represents the size) and you''ll be wearing a big > > > smile every time you work on a system so equipped. > > > > Hmmm, on second glace, 36G versions of that seem to be going for $40. > > Do you mean $140, or am I missing a really good deal somewhere?The first hit on Google Products is for $40. No idea if they are real or reputable or what. http://www.itovernight.com/store/comersus_viewItem.asp?idProduct=866720 -brian -- "Perl can be fast and elegant as much as J2EE can be fast and elegant. In the hands of a skilled artisan, it can and does happen; it''s just that most of the shit out there is built by people who''d be better suited to making sure that my burger is cooked thoroughly." -- Jonathan Patschke
> > http://www.itovernight.com/store/comersus_viewItem.asp > ?idProduct=866720 >Fly by night from the looks of it. http://www.resellerratings.com/store/IToverNight $140 looks like bottom dollar from anywhere reputable (which is more in line with what I would expect). http://castle.pricewatch.com/s/search.asp?s=FUJ-MAX3036RC+&group1=1&sci=26&c=Hard+%2F+Removable+Drives This message posted from opensolaris.org