On 4 April 2012 14:23, Peter Urbanec <linux-raid@xxxxxxxxxxx> wrote: > I'm running Gentoo kernel 3.3.0 with raid5 on four ICH7 AHCI connected > Seagate 2TB 7200RPM disks. I also have two WD 1TB Green disks in raid1 on a > Sil3114 with a JBOD (non-RAID) BIOS. > > When I attempt to do a scrub/check on the raid5, the check seems to proceed > without actually reading any data from the disks - the disk activity lights > do not even flicker. > > Looking at the speed at which the check completes confirms this: > > # cat /proc/sys/dev/raid/speed_limit_min > 10000 > # cat /proc/sys/dev/raid/speed_limit_max > 4000000 > # echo check > devices/virtual/block/md0/md/sync_action > # echo check > devices/virtual/block/md127/md/sync_action > ... > # cat /proc/mdstat > Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] > md127 : active raid1 sdf1[1] sde1[0] > 976760384 blocks [2/2] [UU] > [>....................] check = 1.7% (17387072/976760384) > finish=380.7min speed=41994K/sec > > md0 : active raid5 sdb[1] sda[0] sdd[4] sdc[2] > 5860535808 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] > [UUUU] > [==================>..] check = 93.9% (1835359616/1953511936) > finish=0.8min speed=2332893K/sec > > > raid1 runs at about 42MB/s as expected with two WD 1TB Green drives. > raid5 runs at well over 2GB/s - not really possible with four Seagate 2TB > 7200RPM drives. > > Any ideas on what may be going on there and how to fix it. Let me know > what/if more information may be needed. > > Thanks > > Peter Urbanec > > -- > 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 FWIW I'm seeing this as well, kernel 3.3.1, but on RAID6. There's a message just a few days about this, but no link to a patch. Mathias -- 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
