Hi Tom, 1) regarding Software RAID and TRIM: there is a script raid1ext4trim.sh-1.4 from Chris Caputo that does a TRIM for Ext4 file systems on a software RAID 1. According to the comments in the script it only supports RAID volumes which reside on complete disks (e.g. /dev/sdb and /dev/sdc), not on RAID partitions (e.g. /dev/sdb1 and /dev/sdc1) The script is shipped with hdparm, get hdparm 9.37 at http://sourceforge.net/projects/hdparm/ and you'll find the script in the subfolder hdparm-9.37/wiper/contrib/ I have not tested the script yet, maybe I could do some tests tomorrow 2) regarding choosing the right SSD: I would strongly recommend a SSD with integrated power-outage protection, Intel's 320 series has this inside: http://newsroom.intel.com/servlet/JiveServlet/download/38-4324/Intel_SSD_320_Series_Enhance_Power_Loss_Technology_Brief.pdf I have done some power-outage tests today, including a Vertex-3 and an Intel 320 series. I used diskchecker.pl from http://brad.livejournal.com/2116715.html result: -> for the Vertex 3 diskchecker.pl reported lost data: [root@f15-ocz-vertex3 ~]# ./diskchecker.pl -s 10.10.30.199 verify testfile2 verifying: 0.00% verifying: 1.42% Error at page 52141, 0 seconds before end. verifying: 6.31% Error at page 83344, 0 seconds before end. verifying: 11.12% Error at page 163555, 0 seconds before end. [...] Total errors: 12 Histogram of seconds before end: 0 12 [root@f15-ocz-vertex3 ~]# -> for the Intel 320 Series diskchecker.pl did not report data loss: [root@f15-intel-320 ~]# ./diskchecker.pl -s 10.10.30.199 verify testfile2 verifying: 0.00% verifying: 0.12% [...] verifying: 99.82% verifying: 100.00% Total errors: 0 [root@f15-intel-320 ~]# I did the tests multiple times, I had also some runs on the Vertex 3 without errors, but with the Intel 320 Series no single test reported an error. I did the tests with fedora 15 on the SSDs, here are the details of hdparm -I OCZ Vertex 3: Model Number: OCZ-VERTEX3 Serial Number: OCZ-OQZF2I45DYZ47T3C Firmware Revision: 2.06 Transport: Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0 [...] device size with M = 1000*1000: 120034 MBytes (120 GB) Intel 320 Series: Model Number: INTEL SSDSA2CW160G3 Serial Number: CVPR112601AL160DGN Firmware Revision: 4PC10302 Transport: Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6 [...] device size with M = 1000*1000: 160041 MBytes (160 GB) Regards, Werner On Mon, 2011-07-04 at 10:13 +0100, Tom De Mulder wrote: > On Thu, 30 Jun 2011, Mikael Abrahamsson wrote: > > > From the tests I have read, the Intel 510 are actually worse than the Intel > > X-25 G1/G2/320 models, with exactly the symptoms you're describing. It's fast > > for linear reads and writes, but not so good for random writes, especially not > > when it's getting full. > > Yes; that's why I'm looking forward to also getting some SandForce 22xx > based drives (probably OCZ Vertex 3) to test. > > > Include the Intel 320 as well, I think it should be viable for your usage > > pattern. > > I wasn't too impressed by the Anandtech review of the 320, and (as > everywhere) my funds are limited. :-) > > > -- > Tom De Mulder <tdm27@xxxxxxxxx> - Cambridge University Computing Service > +44 1223 3 31843 - New Museums Site, Pembroke Street, Cambridge CB2 3QH > -> 04/07/2011 : The Moon is Waxing Crescent (17% of Full) > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
