Spelling/typo error.... >From what I understand... If the arrays don't share physical disks, they can re-sync at the same time. Maybe some throttling system is limiting it to just 5 at a time. Maybe CPU load? I don't know if md does things based on how busy the CPU is. Is your CPU maxed out? These are related to throttling: /proc/sys/dev/raid/speed_limit_max /proc/sys/dev/raid/speed_limit_min Do "man md" for more info. The speed limits are per device, not per array. Make sure the max is large enough the permit your disks to go as fast as they can. I use 100000 (100,000K bytes/second). My disks are not that fast, and having too large of a number does not hurt. At least as a test, set the min to the same value as max. I use these commands when I want to change by hand: cat /proc/sys/dev/raid/speed_limit_max cat /proc/sys/dev/raid/speed_limit_min echo 100000 > /proc/sys/dev/raid/speed_limit_max echo 1000 > /proc/sys/dev/raid/speed_limit_min Guy -----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Rechenberg, Andrew Sent: Monday, August 16, 2004 11:24 AM To: linux-raid@xxxxxxxxxxxxxxx Subject: Forcing raid1 resync Hello, Is there anyway to force a resync of RAID1 arrays that need to be resynced? I have 26 RAID1 arrays and when the system shuts down uncleanly, or the machine crashes hard, sometimes I need to hotadd devices back into the array. For example if I have the following in /etc/raidtab: raiddev /dev/md23 raid-level 1 nr-raid-disks 2 persistent-superblock 1 chunk-size 64 device /dev/sdao1 raid-disk 0 device /dev/sdbc1 raid-disk 1 /proc/mdstat for md23 will show: md23 : active raid1 sdbc1[1] 17783808 blocks [2/2] [U_] And I will need to use mdadm or raidhotadd to add /dev/sdao1 back into the array. When I add a device back into the array the reconstruction doesn't start immediately and/or if another reconstruction is underway, the new recontruction will not occur until the first one has completed. Is this behavior expected/by design? Waiting for 26 arrays to reconstruct one at a time is painfully slow. When I created the arrays they all started to sync at the same time so I know the RAID code will sync more than one at a time, and when my box came up yesterday after a hard power cycle, about 5 arrays started syncing, but the rest waited until those were finished and then synced one at a time. I looked through md.c and raid1.c and I see that hot_add_disk() calls md_recover_arrays() which wakes up the md recovery thread, but does the thread only allow one synchronization to occur at a time? Here are some of my system details: Red Hat 7.3 with updates kernel-bigmem-2.4.20-30 with megaraid2 patch If someone could point me in the direction in the code to understand the way this process works I would appreciate it. Let me know if you need any more information. Regards, Andrew Rechenberg Infrastructure Team, Sherman Financial Group - 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 - 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
