On Tue, Mar 12, 2013 at 10:10 PM, Keith Keller < kkeller at wombat.san-francisco.ca.us> wrote: > On 2013-03-12, SilverTip257 <silvertip257 at gmail.com> wrote: > > > > I've not had any MegaRAID controllers fail, so I can only say they've > been > > reliable thus far! > > I think that this is not a helpful comment for the OP. He wants to > know, in the event the controller does fail, can he replace it with a > similar-but-possibly-not-identical controller and have it recognize the > I've had no problem with various versions of Dell MegaRAID/PERC5i controllers. You can swap drives from a PERC5i into a PERC6i for example and things are peachy. But it is not possible to swap drives from a PERC6i into a PERC5i controller. Avoid SAS6/iR controllers ... they are low-end controllers that only support hardware RAID0 and RAID1. Ultimately hardware RAID controllers can be a big pain -- just like anything else it's a good business practice to have spares! > original RAID containers. Just because you have not seen any failures > so far does not mean the OP never will. > > > You start by failing/removing the drive via mdadm. Then hot remove the > > disk from the subsystem (ex: SCSI [0]) and finally physically remove it. > > Then work in the opposite direction ... hot add (SCSI [1]), clone the > > partition layout from one drive to the new with sfdisk, and finally add > the > > new disk/partitions to your softraid array with mdadm. > > > > You must hot remove the disk from the SCSI subsystem or the block device > > (ex: /dev/sdc) name is occupied and unavailable for the new disk you put > in > > the system. I've used the above procedure many times to repair softraid > > arrays while keeping systems online. > > This is basically the same procedure for replacing a failed drive in a > hardware RAID array, except that there is no need to worry about drive > I'll argue that the software RAID process is slightly more complex. And it is crucial that one remember to hot-remove the disk ... after all one could panic their box by just yanking the drive. I think that information will be useful to the OP and others, so I posted it all. I ought to check the CentOS wiki and see if any/all of those steps are documented. > names (since individual drives don't get assigned a name in the kernel). > But the point is that replacing a failed drive is the same amount of > on-site work in either scenario, so that should not deter the OP from > choosing software RAID. (There may be other factors, such as the > aforementioned write cache on many RAID cards.) > > --keith > > > -- > kkeller at wombat.san-francisco.ca.us > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > -- ---~~.~~--- Mike // SilverTip257 //