Adding disk to RAID 5 Array

[John Lynch_2]

I have a Netserver LH3 with a NetRAID card in it (not sure which NetRAID either 1 or 4). There are 2 arrays configured - RAID 1, 2 disks & RAID 5, 3 disks. I want to add another disk to the RAID 5 array, then go into Netware and modify the volumes. I am under the understanding that when the RAID 5 array has another disk added, this creates another logical drive. Can anyone please tell me how to add this 4th disk to the RAID 5?

Thanks in advance

[Iain Marshall]

You will most likely need to do a complete rebuild of Netware. Here's a brief idea, but for a more detailed procedure, check http://support.novell.com/cgi-bin/search/searchtid.cgi?/10027322.htm

It's for Netware 4 and 5, but do a search on Novell's web site for Netware 6 specifically.

1. Make sure you have 2 good backups
2. Have your Netware/Backup software and any other apps' installation CDs and serial numbers handy
3. Use NWCONFIG -> Directory options -> Directory backup and restore options -> Save local NDS information before hardware upgrade
4. Copy SYS:SYSTEM\BACKUP.DS to a workstation
5. Add new disk and reconfig as a 4 disk RAID 5 set up, then reinstall Netware into it's own NDS tree
6. Copy BACKUP.DS to SYS:SYSTEM on the server from the workstation
7. Remove NDS from the server using NWCONFIG -> Directory options -> Remove Directory Services from this server
8. Use NWCONFIG -> Directory options -> Directory backup and restore options -> Restore local NDS information after hardware upgrade, and specify SYS:SYSTEM as the directory containing BACKUP.DS
9. Reinstall Backup software and do a complete restore (including trustees).
10. Reboot

You would be as well to use TBACKUP.EXE to backup and trustees as a precautionary measure.

Hope this helps.

Iain Marshall

[kris rombauts · Accepted solution]

Hi John,

i assume you're using the embedded Netraid controller in the LH3 or any Netraid controller type except for the Netraid 4M.

Expansion only works if you have one logical drive within your raid array, so if the logical drive size is equal to the array size then it can be done.
i.e. 3*9 Gbyte disks in raid5 give you a netto capacity of 18 Gbyte,your logical drive should be equal to 18 Gbyte as a whole. If you happen to have multiple logical drives created in your raid5 array this whole expansion scenario will not work.


See page 8 - 10 in the user manual :

http://h20015.www2.hp.com/content/common/manuals/lpn11577/lpn11577.pdf;jsessionid=AOSTLZN3JGJNXQEXGRMENZQ


Depending on the added disk capacity this takes from 45 min to a couple of hours, for a 3 to 4 disk (18 Gbyte) expansion it takes almost 2 hours.

By doing the above you will still only have one logical drive in your raid5 array, their is no additional logical drive added automatically as you thought but the logical drive's capacity is simply increased.


In the Netraid Assistant utility you will see the below info for your arrays under the

Physicall Devices:
-----------------
A0-0
A0-1 => your RAID1 array

A1-0
A1-1
A1-2 => original RAID5 with 3 disks
A1-3 => added after expansion to 4 disks


Logical Devices: (logical view)
----------------

LD0 -> your raid1 (if only one logical drive
created in the mirror pair)

LD1 -> your raid5 logical drive, does not
change by adding a disk just the size
increases.



At the Netware level you'll have to get the new space assigned and added to your
Volume(s), have a look at page 8-10 in the user guide:

http://h20015.www2.hp.com/content/common/manuals/lpn11577/lpn11577.pdf;jsessionid=AOSTLZN3JGJNXQEXGRMENZQ


HTH

Kris