topic Time to Expand an Array in Disk Enclosures

Time to Expand an Array

Andrew McLean_2 — Mon, 10 May 2004 22:52:09 GMT

I have a 3x72Gb raid 5 array in a ML350G3 which I have added a forth 72Gb drive to. I have set the controller configuration so that the priority on expanding the array is set to high. How long should it take as I started it on Saturday morning and it is now Tuesday and it is still expanding.

Re: Time to Expand an Array

Uwe Zessin — Tue, 11 May 2004 02:17:41 GMT

Andrew,
I have read something about 15 minutes per GigaByte on an otherwise idle controller.

Re: Time to Expand an Array

Andrew McLean_2 — Tue, 11 May 2004 02:24:51 GMT

Thanks for that, given that the disk is hardly idle, I should expect it to take a few more days. I assume that the 15min per Gb is pysical size of the hard disk and not the amount of data currently stored on the disk. Thanks again.

Re: Time to Expand an Array

Uwe Zessin — Tue, 11 May 2004 02:44:52 GMT

Sure, RAID controllers present a list of logical blocks to the host - they don't have an idea of what a filesystem is. Some advanced controllers like the EVA maintain a map of which 'segments' of a virtual disk have data written to and use this knowlege to optimize replication or snapclones, but that does require additional ressources in the system.