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Array Expansion not visible to the OS. ADG problem?

TerenceB
Occasional Advisor

Array Expansion not visible to the OS. ADG problem?

After running Expand Array with 2 new disks added to a Smart Array 6400 Controller they are not visible to the operating system! (Netware 6.5). I ran the expansion using CPQONLIN.NLM and let the utility expand the RAID 5 array using default settings. What has happened as a result is that a new logical drive has been created with RAID ADG!! It looks like this in cpqonlin:
Smart Array 6400 Controller -- slot 3
+-SCSI Array A with Spare
+- 420029 MB, RAID 5 - Log Drive 1
+- 224013 MB, RAID ADG - Log Drive 2

The RAID ADG - Log Drive 2 is not visible as free space in the operating system! I cannot add the 200+ GB to the Netware Pool as expected. I have expanded arrays many times before and have been able to expand pools/volumes directly afterwards, all without taking the server down, but I have never come across ADG before.

What has happened I wonder? Have I lost the 200+ GB to some advanced recovery technology and can't expand the disk volume for the server's users?? The existing volume is 98% full so this is an urgent problem.

Any help or explanation would be very much appreciated...
5 REPLIES
e4services
Honored Contributor

Re: Array Expansion not visible to the OS. ADG problem?

That is the weirdest thing I have ever seem. The controller could not have been expanding the existing array if this is your outcome, it created a new array. An expanded array should be one array. AND RAID 6 with HP Advanced Data Guarding had to have been enabled to boot, to even get a RAID 6.
From what I understand, you can not go back from RAID 6 to 5, so I think your only way out now is to backup, clear the Array Configuration and start over.
Hot Swap Hard Drives
e4services
Honored Contributor

Re: Array Expansion not visible to the OS. ADG problem?

Hey, I was thinking, if your original Array, the RAID 5, is still accessable, yes? Did it expand? THat is what was the original size? But it too must have been RAID 6 not 5 if you now have RAID 6, that is RAID 6 must have been enabled and active for a simple expansion.
And, yes, the RAID 6 does take 1/3 more disk space than the RAID 5, but you show 50%, so does the utilization of RAID 6 explain the way cpqonlin displays the config? RAID 5, it is said, utilizes 67% of the capacity while RAID 6 50%, so it could be a single RAID 6 ADG in 640GB = 1 420GB logical, as well as RAID 5 takes 3 disks where 6 takes 4.
Hot Swap Hard Drives
TerenceB
Occasional Advisor

Re: Array Expansion not visible to the OS. ADG problem?

Hi,

Thanks very much for your replies. Yes the original Array is still accessible (otherwise I would be in BIG trouble!). But the size is exactly as it was before running the expansion, and the two disks that were added have become a separate Logical Drive. And worst of all, this drive is invisible to the operating system. In normal circumstances it would have appeared as free space and I would be able to expand a Pool or create a new pool. The only way I can see it from the OS is via a Hardware Adapters summary which displays this:

HP Unified RAID Driver Slot: 301
Device Name Device Type Capacity TID LUN Object ID
HP Smart Array 6400 Slot 3 ID 0 LUN 1 Hard Disk 224013 MB 0 1 14h
HP Smart Array 6400 Slot 3 ID 0 LUN 0 Hard Disk 420028 MB 0 0 8h

But the 224013 MB is not available as Free Space where it should be, which looks like this (precisely as it was before running the expansion).

[V504-A3-D0:0] HP Smart Array 6400 Slot 3 ID 0 LUN 0 (410.18 GB)
[V504-A3-D0:0-P0] NSS Partition (400 GB) Set Partition Label
Used by NSS Pool:POOLA
[V504-A3-D0:0-P64000] NSS Partition (10.18 GB) Set Partition Label
POOLA (410.18 GB) Add a Volume Expand Pool

I actually took a screen shot of the expansion operation. This is what it looked like when the 2 new disks were available for expanding the array. I selected the disks and Accept Changes, precisely "as normal".

+------------------------------------------------------------------------------+
Smart Array Configuration 2.84 NetWare Loadable Module
+------------------------------------------------------------------------------+

+-----------------------------------------------+ +--------------------------+
Physical Drives Available Expand Array
----------------------------------------------- --------------------------
146.8 GB, Port 1, ID 5, SCSI Assign Drive to Array
146.8 GB, Port 1, ID 8, SCSI Remove Drive from Array
+-----------------------------------------------+ Accept Changes
+--------------------------+



+-----------------------------------------------+
Expand Existing Array
-----------------------------------------------
146.8 GB, Port 1, ID 0, SCSI
146.8 GB, Port 1, ID 1, SCSI
146.8 GB, Port 1, ID 2, SCSI
146.8 GB, Port 1, ID 3, SCSI
146.8 GB, Port 1, ID 4, SCSI Spare
+-----------------------------------------------+

There is just one thing that seems a bit weird in screen dump - i.e. why is the second of the Physical Drives Available numbered ID 8? Shouldn't it be 6?

Whatever I do now, I fear that the situation is as you described in your first reply - backup, clear the Array Configuration and start over. But that is a mammoth job, on a volume that is supposed to be available 24x7. Another alternative is to leave it as it is, acquire more new disks and start a new Array on a new controller.

We will be speaking to HP Support (and probably our Sales Reps!) about this.
Víctor Cespón
Honored Contributor

Re: Array Expansion not visible to the OS. ADG problem?

Let's go back to the beggining. You had an array with disks ID 0, 1, 2 and 3, with ID 4 as spare. This gives a 420 GB logical unit in RAID 5.
Then you added ID 5 and 8. This gives you 280 GB more of raw space. A logical unit is misteriously created in that space, the original has not been modified.
Can you try to delete that new logical drive and then extend the logical drive 1 over the empty space?
TerenceB
Occasional Advisor

Re: Array Expansion not visible to the OS. ADG problem?

Thanks for the suggestion. Yes the scenario is as you summarized. I have thought about deleting the logical drive. But I'm pretty certain that I won't be able to then extend logical drive 1 in cpqonlin. There is no such option in that online utility. Perhaps the option might be available in the System Configuration Utility, but I can't possibly take the server down to even just look at it.

Also, I'm going to get HP Support involved before trying anything. There is obviously something very weird about this configuration and we shouldn't have to try to figure out how to fix it.