which CPU for XOR?
What type of operation is XOR anyway? Should be ALU, right? So - what CPU is best for software raid? One with high integer processing power? Dex -- -BEGIN GEEK CODE BLOCK- Version: 3.12 GCS d--(+)@ s-:+ a- C+++() UL+ P+++ L+++ E-- W++ N o? K- w--(---) !O M+ V- PS++(+) PE(-) Y++ PGP t++(---)@ 5 X+(++) R+(++) tv--(+)@ b++(+++) DI+++ D G++ e* h++ r%* y? --END GEEK CODE BLOCK-- http://www.stop1984.com http://www.againsttcpa.com - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
raid 5 read performance
Neil hello Sorry for the delay. too many things to do. I have implemented all said in : http://www.spinics.net/lists/raid/msg11838.html As always I have some questions: 1. mergeable_bvec I did not understand first i must admit. now i do not see how it differs from the one of raid0. so i actually copied it and renamed it. 2. statistics. i have added md statistics since the code does not reach the statics in make_request. it returns from make_request before that. 3. i have added the new retry list called toread_aligned to raid5_conf_t . hope this is correct. 4. your instructions are to add a failed bio to sh, but it does not say to handle it directly. i have tried it and something is missing here. raid5d handle stripes only if conf-handle_list is not empty. i added handle_stripe and and release_stripe of my own. this way i managed to get from the completion routine: R5: read error corrected!! message . ( i have tested by failing a ram disk ). 5. I am going to test the non common path heavily before submitting you the patch ( on real disks and use several file systems and several chunk sizes). It is quite a big patch so I need to know which kernel do you want me to use ? i am using poor 2.6.15. I thank you -- Raz - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: which CPU for XOR?
Followup to: [EMAIL PROTECTED] By author:Dexter Filmore [EMAIL PROTECTED] In newsgroup: linux.dev.raid What type of operation is XOR anyway? Should be ALU, right? So - what CPU is best for software raid? One with high integer processing power? Something with massive wide vector registers. PowerPC with Altivec totally kicks ass; x86-64 isn't too bad either. There are also some processors with builtin RAID accelerators; at least Intel, Broadcom and AMCC make them. -hpa - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: raid 5 read performance
On Friday June 9, [EMAIL PROTECTED] wrote: Neil hello Sorry for the delay. too many things to do. You aren't alone there! I have implemented all said in : http://www.spinics.net/lists/raid/msg11838.html As always I have some questions: 1. mergeable_bvec I did not understand first i must admit. now i do not see how it differs from the one of raid0. so i actually copied it and renamed it. Sounds fine. For raid5 there is no need to force write requests to be split up, but that's a minor difference. 2. statistics. i have added md statistics since the code does not reach the statics in make_request. it returns from make_request before that. Why not put the code *after* that? Not that it matters a great deal. I'll comment more when I see the code I expect. 3. i have added the new retry list called toread_aligned to raid5_conf_t . hope this is correct. Sounds good. 4. your instructions are to add a failed bio to sh, but it does not say to handle it directly. i have tried it and something is missing here. raid5d handle stripes only if conf-handle_list is not empty. i added handle_stripe and and release_stripe of my own. this way i managed to get from the completion routine: R5: read error corrected!! message . ( i have tested by failing a ram disk ). Sounds right, but I'd need to see the code to be sure. 5. I am going to test the non common path heavily before submitting you the patch ( on real disks and use several file systems and several chunk sizes). I'd rather see the patch earlier, even if it isn't fully tested. It is quite a big patch so I need to know which kernel do you want me to use ? i am using poor 2.6.15. A patch against the latest -mm would be best, but I'm happy to take it against anything even vaguely recent. However, it needs to be multiple patches, not just one. This is a *very* important point. As that original email said: This should be developed and eventually presented as a sequence of patches. There are several distinct steps in this change and they need to be reviewed separately or it is just too hard. So I would really like it if you could separate out the changes into logically distinct patches. If you can't or won't, then still send the patch, but I'll have to break it up so it'll probably take longer to process. Thanks for your efforts, NeilBrown - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Failed Hard Disk... help!
Hello all... I'm looking for a suggestion or two... I have a server running with 2 Western Digital WD4000YR drives running a RAID1 mirror... the other day, I was lucky enough to have one of the drives fail. Being as they are new(er) drives, they are still under warrenty, and I'm looking to do an advanced replacement RMA to swap the drive and allow it to rebuild. The problem is... I don't have the serial numbers of the hard drives. No big deal... except, they are SATA drives, and I'm running 2.6.14.6 honestly, with the main drive of the mirror failed, I'm afraid to upgrade. I'm also afraid to upgrade, because I'm still using mdadm v2.2 with v1.00.02 superblocks. I had a recent raid disaster here at home (see another thread, long story short - every reboot, the raid 5 rebuilds... during one of those rebuilds, a disk really failed. bye bye data) - during all my attempts to recover from it, I upgraded to a newer mdadm and kernel, and it refused to recognize my raid superblocks! I had to revert to mdadm 2.2, and the old kernel to see the superblocks again (still... 26 of 28, did me little good... and forcing 27 of 28 with 1 missing using the partially rebuilt disk, I think did even less good). What options do I have to retreive the serial number without driving out to the datacenter and looking at the drive? Do I need to be afraid of upgrading my kernel and mdadm and having my superblock go poof? -([EMAIL PROTECTED])-(/)- # mdadm --version mdadm - v2.2 - 5 December 2005 -([EMAIL PROTECTED])-(/)- # mdadm --detail /dev/md_d0 /dev/md_d0: Version : 01.00.02 Creation Time : Thu Jan 5 19:49:04 2006 Raid Level : raid1 Array Size : 390711376 (372.61 GiB 400.09 GB) Device Size : 390711376 (372.61 GiB 400.09 GB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Fri Jun 9 19:04:40 2006 State : clean, degraded Active Devices : 1 Working Devices : 1 Failed Devices : 0 Spare Devices : 0 Name : CRUX x64 UUID : c622e6f7:2765c0fb:7516cdf1:3ee5b706 Events : 13085584 Number Major Minor RaidDevice State -1428255432 0010922 removed 1 8 161 active sync /dev/sdb -([EMAIL PROTECTED])-(/)- # uname -ar Linux xenogenesis 2.6.14.6 #1 SMP Wed Jan 25 20:07:07 EST 2006 x86_64 x86_64 x86_64 GNU/Linux -([EMAIL PROTECTED])-(/)- # Thanks, David M. Strang - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Failed Hard Disk... help!
/Patrick wrote: pretty sure smartctl -d ata -a /dev/sdwhatever will tell you the serial number. (Hopefully the kernel is new enough that it supports SATA/smart, otherwise you need a kernel patch which won't be any better...) Yep... 2.6.15 or better... I need the magical patch =\. Any other options? -- David - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Failed Hard Disk... help!
On Fri, Jun 09, 2006 at 07:44:40PM -0400, David M. Strang wrote: /Patrick wrote: pretty sure smartctl -d ata -a /dev/sdwhatever will tell you the serial number. (Hopefully the kernel is new enough that it supports SATA/smart, otherwise you need a kernel patch which won't be any better...) Yep... 2.6.15 or better... I need the magical patch =\. Any other options? scsi_id from udev, if you are lucky enough L. -- Luca Berra -- [EMAIL PROTECTED] Communication Media Services S.r.l. /\ \ / ASCII RIBBON CAMPAIGN XAGAINST HTML MAIL / \ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
