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How long for RAID 5 initialization..

steve_682
Occasional Visitor

How long for RAID 5 initialization..

I have an HP/Compaq ML570 currently up and running as an Exchange server. I added four 300gb drives and I have configured them to be a RAID 5 array. The array will be 858GB.

The question I have is how long will the initialization take? I was advised that it would take 10 to 15 minutes per gig. So that equates to about 6 to 9 days for the drives to initialize. Sounds crazy to me. Anyway, it's been 11 days and the drives are still not ready. Could the initialization have timed out? There is no tool to monitor status. The HP Array Config Utility simply states the status as Background Parity Initializing/Queued.

I'm wondering if I should let it continue or kill the process and start over.
2 REPLIES
Steven Clementi
Honored Contributor

Re: How long for RAID 5 initialization..

Steve:

If you can fine an older copy of the ACU software, it would give you a % indication as to the status and progress of the initialization.

The software can be foune on an older Smart Start CD. I would try 5.5 if you have one.



Steven
Steven Clementi
HP Master ASE, Storage and Clustering
MCSE (NT 4.0, W2K, W2K3)
VCP (ESX2, Vi3, vSphere4, vSphere5)
RHCE
NPP3 (Nutanix Platform Professional)
Glenn N Wuenstel
Valued Contributor

Re: How long for RAID 5 initialization..

Hey Steve,
The PI doesn't start until the LUN has had its first write. So, if you created the LUNs and then did not present them to a server and do an init like formating the drive then the PI will never start.
Once PI has started you can use ACU to monitor the percentage. You can also go to the CLI and do a "show units" and it will display each unit and the PI status percentage or "Complete".
Make sure that you change the Rebuild priority to Medium or High (I suggest medium) before you init the drives. The reason is that if the Rebuild priority is Low when the first process kicks off and then you change the priority to Medium or High the process in progress won't change unless you reboot the array.
Here is the deal with the priorities:
Low -- if any host access is detected the Rebuild process will pause for a time and then retry; this is a problem if you have agents or a cluster that is "pinging" the drive every few seconds just to check its status.
Medium -- this will round robin time-slice at about 50/50 for PI and data access.
High -- this will round robin time-slice at around 60-70/40-30 (yeah I know this is vague but I can't remember the exact numbers).

Hope this helps,
Glenn