> What you could do is set the number of devices in the array to 3 so > they it always appears to be degraded, then rotate your backup drives > through the array. The number of dirty bits in the bitmap will > steadily grow and so resyncs will take longer. Once it crosses some > threshold you set the array back to having 2 devices to that it looks > non-degraded and clean the bitmap. Then each device will need a full > resync after which you will get away with partial resyncs for a while. I don't undertand why clearing the bitmap causes a rebuild of all devices. I think I have a conceptual misunderstanding. Consider a RAID-1 and three physical disks involved, A,B,C 1) A and B are in the RAID, everything is synced 2) Create a bitmap on the array 3) Fail + remove B 4) Hot add C, wait for C to sync 5) Fail + remove C 6) Hot add B, wait for B to resync 7) Goto step 3 I understand that after a while we might want to clean the bitmap and that would trigger a full resync for drives B and C. I don't understand why it would ever cause a resync for drive A. - 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
