Re: raid 5 read performance
On Sun, 21 May 2006, Neil Brown wrote: > Please read > > http://www.spinics.net/lists/raid/msg11838.html > > and ask if you have further questions. Neil, what is the current status on the slow read performance with 2.6 ? Regards, Stephan - 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
mdadm 2.2 segmentation fault
when i try to start my raid with mdadm 2.2 it gives a segfault : ]# mdadm -A /dev/md0 Segmentation fault and dmesg shows : md: md0 stopped. mdadm 1.12 shows : ]# mdadm -A /dev/md0 mdadm: /dev/md0 has been started with 15 drives. after i start the md0 with mdadm 1.12, it looks like 2.2 is working ok : ]# mdadm -D /dev/md0 /dev/md0: Version : 00.90.03 Creation Time : Wed Dec 1 16:38:32 2004 Raid Level : raid5 Array Size : 2461523456 (2347.49 GiB 2520.60 GB) Device Size : 175823104 (167.68 GiB 180.04 GB) Raid Devices : 15 Total Devices : 15 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Fri Jan 27 14:06:15 2006 State : clean Active Devices : 15 Working Devices : 15 Failed Devices : 0 Spare Devices : 0 Layout : left-symmetric Chunk Size : 256K UUID : 784fce06:6999eec1:ad90674e:e415169f Events : 0.3082763 Number Major Minor RaidDevice State 0 8 490 active sync /dev/sdd1 1 8 331 active sync /dev/sdc1 2 8 172 active sync /dev/sdb1 3 8 653 active sync /dev/sde1 4 8 814 active sync /dev/sdf1 5 8 975 active sync /dev/sdg1 6 8 1136 active sync /dev/sdh1 7 8 1297 active sync /dev/sdi1 8 8 1458 active sync /dev/sdj1 9 8 1619 active sync /dev/sdk1 10 8 177 10 active sync /dev/sdl1 11 8 193 11 active sync /dev/sdm1 12 8 209 12 active sync /dev/sdn1 13 8 225 13 active sync /dev/sdo1 14 8 241 14 active sync /dev/sdp1 is there anything i can test/debug ? - 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: Live Read Error Correction W/O Reconstruct?
On Tue, 24 Jan 2006, Neil Brown wrote: On Monday January 23, [EMAIL PROTECTED] wrote: In 2004, Mr Brown wrote that read errors could be handled without reconstruction. Has this been implemented in 2.6.8? As I understand it, this is the way RAID is supposed to work. Not in 2.6.8. It is implemented in 2.6.15 for raid5 and 2.6.16-rc1 for raid1 and raid6. Neil, is there anything logged in case this read error occurs ? (which can be fixed) - 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: Better handling of readerrors with raid5.
On Thu, 22 Dec 2005, Andrew Burgess wrote: i recovered my raid by using dd_rescue the last failed disk to a spare disk (with 4 read errors) (and doing a mdadm -A -force) (so I should have a corrupted file somewhere?) Or a corrupted filesystem, which e2fsck will find & fix. filesystem is xfs and to make sure i runned xfs_check (which runned for a while with no output) afther this the dmesg output after mounting : XFS mounting filesystem md0 Ending clean XFS mount for filesystem: md0 Did you write down the bad sectors? If so, you can use debugfs to find out where they are on the filesystem. Computing the filesystem block number from the device sector number will be an exercise... dd_rescue made a logfile : dd_rescue: (warning): /dev/sdb1 (39297916.0k): Input/output error! dd_rescue: (warning): /dev/sdb1 (39297916.5k): Input/output error! dd_rescue: (warning): /dev/sdb1 (39297917.0k): Input/output error! dd_rescue: (warning): /dev/sdb1 (39297917.5k): Input/output error! - 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: [PATCH md ] Better handling of readerrors with raid5.
On Fri, 16 Sep 2005, NeilBrown wrote: TESTERS WANTED!! SEE BELOW... This patch changes the behaviour of raid5 when it gets a read error. Instead of just failing the device, it tried to find out what should have been there, and writes it over the bad block. For some media-errors, this has a reasonable chance of fixing the error. If the write succeeds, and a subsequent read succeeds as well, raid5 decided the address is OK and conitnues. Neil, what is the current status of this patch ? yesterday one of my disks decided to fail during the night (3ware ide timeout) during the rebuild one of my disks decided it had a read error so the raid was 'down' i recovered my raid by using dd_rescue the last failed disk to a spare disk (with 4 read errors) (and doing a mdadm -A -force) (so I should have a corrupted file somewhere?) looks like this patch would help in situations like this - 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: non-optimal RAID 5 performance with 8 drive array
On Sun, 6 Mar 2005, Nicola Fankhauser wrote: hi On Sun, 2005-03-06 at 15:25, Stephan van Hienen wrote: which kernel are you using ? currently 2.6.8. 2.4: write 100MB/s read 140MB/s 2.6 write 100MB/s read 280MB/s are you sure that 2.6 gives you better read performance than 2.4? it's been reported the other way 'round. oops typo 2.4 does 280MB/s and 2.6 140MB/s - 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: non-optimal RAID 5 performance with 8 drive array
On Tue, 1 Mar 2005, Nicola Fankhauser wrote: the array (reading the first 8GiB from /dev/md0 with dd, bs=1024K) performs at about 174MiB/s, accessing the array through LVM2 (still with bs=1024K) only 86MiB/s. Nicola, which kernel are you using ? 2.4 vs 2.6 performance on my machine (and same problem on different machines) raid5 13 disks 2.4: write 100MB/s read 140MB/s 2.6 write 100MB/s read 280MB/s - 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: slow raid5 performance kernel 2.6 vs 2.4
Is there any news about this problem ? On Tue, 14 Dec 2004, Neil Brown wrote: On Sunday December 12, [EMAIL PROTECTED] wrote: Hi, system : P4 2.4GHz HT, 1GB DDR 8* S-ATA 250GB Hitachi on 2 Si3114 controllers bonnie performance with 2.4 : block input 126MB/sec with 2.6 : block input 90MB/sec saw another posting about slow read performance with raid5 and 2.6 any ideas yet how to fix this ? Not yet. I've been doing some testing which you can read about at http://neilb.web.cse.unsw.edu.au/~neilb/01102979338 I only get a drop from about 250 to 220 on my hardware, which still isn't good. I've got a few ideas but I'm not sure when I will have a chance to follow through with them. I'm doing a bit more testing first to make sure I have a complete picture. 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 - 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 - 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
