How calculate how many time need for add a disk to Raid 5

[Pablo Bauer]

I need to add a disc to a RAID 5 that already has 3 discs of 72GB each one. My question is if esxiste some formulates to be able to calculate whichever time takes to make this task the disc that I am going to add is of 72GB

[Colin_29]

The amount of time it takes to perform an online capacity expansion depends on several parameters:
drive speed, the server microprocessor speed, the amount of other I/O work the server is doing, and the priority level of the capacity expansion. This priority level can be changed from low (the default in ACU) to medium or high to expand the volumes as quickly as possible. Depending on these factors, the expansion process takes somewhere between 10-15 minutes per GB.

[Pablo Bauer]

I have that configuration
1 server ML350G4 with
2 procesors Xeon 3.2Ghz
2 Gb RAM
1 controller 641
2 disk 36Gb in Raid 1
3 disk 72GB in Raid 5 ok 10K

I tray add a 4th disk to raid 5 this disk is 72GB ok 10K

I do the expansion with smat star

[Colin_29]

A couple of things:

I think you need Battery Backed Write Cache to perform a migration and this is an option on the 641 controller, so check that you have it.

I have never tried to do what you are attempting. If you added a third drive of the same size, then it should work. If you already had RAID5 and were adding a fourth disk, then that would work but would only use 36GB of the disk. But adding a larger disk while migrating the RAID from 1 to 5 ?????

Sorry I can't be of any more help, maybe this will spark some other members to say if they think it will work.

[Colin_29]

Sorry just read your second post again.

So you are trying to add a fourth disk to a RAID5. I was making it more complicated than it was.

Yes the 641 will accomodate 6 drives, but I still think you need Battery Backed Write Cache.

[Colin_29]

And you use the Array Configuration Utility (ACU), not SmartStart.