Re: [PERFORM] SSDs again, LSI Warpdrive 2 anyone?
Hi Mark, I work for the division at LSI that supports the Nytro WarpDrive and can confirm that these support poweroff safety (data is persistent in the event of an abrupt loss of power). The Nytro WarpDrive has onboard capacitance to sync intermediate ram buffers to flash, and after powerloss the card is imediately available for use (even as a boot device). There is lots more information on Nytro Products here: http://www.thesmarterwaytofaster.com/ http://www.thesmarterwaytofaster.com/ As well as a place to apply for a free trial of the products, so if you would like to give it a try let me know. Jamon Bowen -- View this message in context: http://postgresql.1045698.n5.nabble.com/SSDs-again-LSI-Warpdrive-2-anyone-tp5715589p5715953.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
[PERFORM] SSDs again, LSI Warpdrive 2 anyone?
A vendor has recommended the above drive to us - anyone have experience with it or its predecessor Warpdrive? http://www.storagereview.com/lsi_warpdrive_2_lp_display_idf_2011 http://www.storagereview.com/lsi_warpdrive_slp300_review The specs look quite good, and the cards have capacitors on them - however I can't see any *specific* mention about poweroff safety (am going to follow that up directly myself). Cheers Mark -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] SSDs again, LSI Warpdrive 2 anyone?
On 06/07/12 12:51, Mark Kirkwood wrote: A vendor has recommended the above drive to us - anyone have experience with it or its predecessor Warpdrive? http://www.storagereview.com/lsi_warpdrive_2_lp_display_idf_2011 http://www.storagereview.com/lsi_warpdrive_slp300_review The specs look quite good, and the cards have capacitors on them - however I can't see any *specific* mention about poweroff safety (am going to follow that up directly myself). Seems like the Warp Drive 2 was a pre-release name, Nytro is the actual appellation. http://www.lsi.com/channel/products/storagecomponents/Pages/SolidState.aspx Cheers Mark -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
[PERFORM] SSDs
Tried harder to find info on the write cycles: found som CFs that claim 2million cycles, and found the Mtron SSDs which claim to have very advanced wear levelling and a suitably long lifetime as a result even with an assumption that the underlying flash can do 100k writes only. The 'consumer' MTrons are not shabby on the face of it and not too expensive, and the pro models even faster. But ... the spec pdf shows really hight performance for average access, stream read *and* write, random read ... and absolutely pants performance for random write. Like 130/s, for .5k and 4k writes. Its so pants it looks like a misprint and it doesn't seem to square with the review on tomshardware: http://www.tomshardware.com/2007/11/21/mtron_ssd_32_gb/page7.html Even there, the database IO rate does seem lower than you might hope, and this *might* be because the random reads are very very fast and the random writes ... aren't. Which is a shame, because that's exactly the bit I'd hope was fast. So, more work to do somewhere. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] SSDs
My colleague has tested a single Mtron Mobo's and a set of 4. He also mentioned the write performance was pretty bad compared to a Western Digital Raptor. He had a solution for that however, just plug the SSD in a raid-controller with decent cache performance (his favorites are the Areca controllers) and the bad write performance is masked by the controller's cache. It wood probably be really nice if you'd get tuned controllers for ssd's so they use less cache for reads and more for writes. Best regards, Arjen On 2-4-2008 8:16, James Mansion wrote: Tried harder to find info on the write cycles: found som CFs that claim 2million cycles, and found the Mtron SSDs which claim to have very advanced wear levelling and a suitably long lifetime as a result even with an assumption that the underlying flash can do 100k writes only. The 'consumer' MTrons are not shabby on the face of it and not too expensive, and the pro models even faster. But ... the spec pdf shows really hight performance for average access, stream read *and* write, random read ... and absolutely pants performance for random write. Like 130/s, for .5k and 4k writes. Its so pants it looks like a misprint and it doesn't seem to square with the review on tomshardware: http://www.tomshardware.com/2007/11/21/mtron_ssd_32_gb/page7.html Even there, the database IO rate does seem lower than you might hope, and this *might* be because the random reads are very very fast and the random writes ... aren't. Which is a shame, because that's exactly the bit I'd hope was fast. So, more work to do somewhere. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] SSDs
On Wed, Apr 2, 2008 at 1:16 AM, James Mansion [EMAIL PROTECTED] wrote: Tried harder to find info on the write cycles: found som CFs that claim 2million cycles, and found the Mtron SSDs which claim to have very advanced wear levelling and a suitably long lifetime as a result even with an assumption that the underlying flash can do 100k writes only. The 'consumer' MTrons are not shabby on the face of it and not too expensive, and the pro models even faster. But ... the spec pdf shows really hight performance for average access, stream read *and* write, random read ... and absolutely pants performance for random write. Like 130/s, for .5k and 4k writes. Its so pants it looks like a misprint and it doesn't seem to square with the review on tomshardware: http://www.tomshardware.com/2007/11/21/mtron_ssd_32_gb/page7.html Even there, the database IO rate does seem lower than you might hope, and this *might* be because the random reads are very very fast and the random writes ... aren't. Which is a shame, because that's exactly the bit I'd hope was fast. So, more work to do somewhere. if flash ssd random write was as good as random read, a single flash ssd could replace a stack of 15k disks in terms of iops (!). unfortunately, the random write performance of flash SSD is indeed grim. there are some technical reasons for this that are basically fundamental tradeoffs in how flash works, and the electronic processes involved. unfortunately even with 10% write 90% read workloads this makes flash a non-starter for 'OLTP' systems (exactly the sort of workloads you would want the super seek times). a major contributing factor is that decades of optimization and research have gone into disk based sytems which are pretty similar in terms of read and write performance. since flash just behaves differently, these optimizations read this paper for a good explanation of this [pdf]: http://tinyurl.com/357zux my personal opinion is these problems will prove correctable due to improvements in flash technology, improvement of filesystems and raid controllers in terms of flash, and introduction of other non volatile memory. so the ssd is coming...it's inevitable, just not as soon as some of us had hoped. merlin -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
