On Monday August 16, ARechenberg@xxxxxxx wrote: > > 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. In 2.4, resyncing of multiple arrays can happen in parallel, providing they don't share physical drives, but reconstruction (i.e. after hot-add) does not. I believe that this is accidental rather than deliberate. In 2.6, both resync and reconstruction can happen in parallel (again, providing there is no sharing of drives). However after a crash, you should not need to hot add any drives. All arrays should still be intact, but will need to be resynced (though in 2.6, this is sometimes avoided). Maybe there is something wrong with your configuration that means that some arrays are never assembled correctly. If you are using "raidstart" to start your arrays, my advice is: Don't. If you are using in-kernel autodetect, then make sure that every partition has the correct partition type (0xFD I think), otherwise you will certainly get exactly the results you see. NeilBrown - 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
