> -----Original Message----- > From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > owner@xxxxxxxxxxxxxxx] On Behalf Of Nils-Henner Krueger > Sent: Wednesday, March 30, 2005 4:13 AM > To: linux-raid@xxxxxxxxxxxxxxx > Subject: syncing RAID1 with more than 10MB/sec > > Syncing a raid1 takes long time for large disks because of > the 10MB/sec limit: > > Mar 30 10:58:31 imap1 kernel: raid1: raid set md2 not clean; > reconstructing mirrors > Mar 30 10:58:31 imap1 kernel: raid1: raid set md2 active with 2 out of 2 > mirrors > Mar 30 10:58:31 imap1 kernel: md: syncing RAID array md2 > Mar 30 10:58:31 imap1 kernel: md: minimum _guaranteed_ reconstruction > speed: 100 KB/sec/disc. > Mar 30 10:58:31 imap1 kernel: md: using maximum available idle IO > bandwith (but not more than 10000 KB/sec) for reconstruction. > > Is it possible to raise this value (without recompiling)? > I know about possible performance tradeoffs with other > processes, I'm just generally interested. > > Thanks. > > nils-henner Yes. For details: man md The default of 10,000 has been increased to 100,000 in newer kernels. I don't know which kernels. If you want to override the defaults you could add these 3 lines to /etc/sysctl.conf: # RAID rebuild min/max speed K/Sec per device dev.raid.speed_limit_min = 1000 dev.raid.speed_limit_max = 100000 Adjust above as required. The above will take effect after a reboot. To see current values type these 2 lines: cat /proc/sys/dev/raid/speed_limit_min cat /proc/sys/dev/raid/speed_limit_max To temporarily change the defaults use these 2 commands: echo 1000 > /proc/sys/dev/raid/speed_limit_min echo 100000 > /proc/sys/dev/raid/speed_limit_max Adjust above as required. The above will take effect now. Guy - 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
