Raid1 not rebuilding.

Question

We need some help with procedure to restore a Raid1 virtual disk.

We are running a PE2400 with a PERC 2/Si. With 6 array disks we have 3 mirrored (Raid1) virtual disks. Before doing some work on two of the pairs we removed one of the mirrors from each (for DR purposes). Once the work was completed, successfully, we replaced the disks. One pair (disk 2 and 3) immediately began rebuilding and is now synched and healthy. The other pair (disk 4 and 5) did nothing. The replaced disk (4), however, reported ready. Looked at Reconfigure... in the Virtual disk but Raid1 was not on offer.

Primary suspicion: the 2 identical seagate disks are not "exactly" identical in size. And yet they were perfectly happy in a mirror last week.

We have now moved on a few more steps having tried a few things (realising maybe we should have asked questions earlier) so need to get ourselves back on track. We tried to initialize the disk again. Reconfigure... only gave concatenate and Raid0. Then tried Unmirror which has, of course, left disk 5 on it's own. Reconfigure... still only gives same options. Now we have even done a lengthy format to no avail.
Now array disk 4 reports... capacity 136.73GB Unallocated 15.00KB (note kilob)
But array disk 5 reports... capacity 136.73GB Unallocated 0.00MB (note megab)

The second post in thread http://forums.us.dell.com/supportforums/board/message?board.id=pes_hardrive&message.id=18583 gave some creedence to our thoughts that the 2 disks are not being seen as being identical.

Looking for some forward thoughts from here?

I am using OpenManage 3.4.0 on w2000 workstation. The OS in the server is NetWare5.1

tester25 · Answer

So your goal at this point is to get Disk 4 and Disk 5 to create a RAID1 Vdisk?    And you are using OpenManage Array Manager 3.4 on that Netware server?   Do you need to preserve any data from the original RAID1 Vdisk that you had made using Disk 4 and Disk 5?  If so, I have a feeling that you probably lost that data after you did the format to those two disks.  Perhaps you already know this though, probably so.

PenPal · Answer

Fortunately not that dire - yet. No primary data is lost, just the redundancy. Array disk 5 is still in the original virtual disk and it is operating perfectly in the production machine (serving up data files as usual). Array disk 4 which was in that same virtual disk as Raid1 is now out on it's own, very healthy, (by all accounts that I have thought to look at) but reluctant to go back into the virtual disk as Raid1. Every time I try it offers only "concatenate" or "Raid0". The only reason I can think of that it will not offer me Raid1 is that the disk is not big enough - but it used to be...just last week. Is there some (un)format option or other that I can use to force the disk to include the 15KB it reports as unallocated space? Will this make the disk recognizable as the same size and therefore offer the option of Raid1 - Or am I barking up the wrong tree?

I suspect it would be an easier (array build) job if I had lost the 60GB of data and didn't care but the data on disk 5 is online and used daily.

tester25 · Answer

You should do an initialize on each of those two disks that you are having the problem on.  Immediately after doing that, try to create a virtual disk using them.  It should work at that point.

barhampa · Answer

The BIOS Configuration Utility does not detect a replaced physical drive in a RAID 1 array and offer the option to start a rebuild.

After the drive is replaced, the utility shows all drives online and all logical drives reporting optimal state. It does not allow rebuild because no failed drives are found.

This occurs if you replace the drive with a drive that contains data. If the new drive is blank, this problem does not occur.

If you exit from this screen and restart the server, the system will not find the operating system.

Perform the following steps to solve this problem:

Access the BIOS Configuration Utility and select Objects—> Physical Drive to display the list of physical drives.
Use the arrow key to select the newly inserted drive, then press .

The menu for that drive displays.

Select Force Offline and press .

This changes the physical drive from Online to Failed.

Select Rebuild and press .

After rebuilding is complete, the problem is resolved and the operating system will boot.

PenPal · Answer

>You should do an initialize on each of those two disks that you are having the problem >on. Immediately after doing that, try to create a virtual disk using them. It should >work at that point.

But if I initialize both disk 4 and disk 5 won't I lose the data on disk 5 (which happens to be critical data)?

PenPal · Answer

Issue resolved. Needed to create a new virtual disk using the empty array disk(4) which for some reason became 15K smaller than it's counterpart. Created the same OS structure on it and copied the entire contents of the original (live data) from the old virtual disk onto it. Rename the volumes to decommission use of the old virtual disk. Deleted the old virtual disk (both in array manager and BIOS) to release array disk(5) then modified the new virtual disk to include the now unallocated array disk(5) and for the first time, the option to RAID1 is available.

The end result is that I have a virtual disk that is 15K smaller than before and the data is now mirrored. No data lost and restore from tape/backup was not needed. Limitation: needed to have the data offine during the copy to ensure all was migrated (approximately 8 hours in our case). Our copy method dropped files with names including non-standard non-english characters - we had to hunt these down individually after the copy before deleteing the original virtual disk.

PowerEdge HDD/SCSI/RAID

Raid1 not rebuilding.

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