Disk Enclosures

Re: Best practice for reseating array disks?

Bill Kriner
Occasional Contributor

Best practice for reseating array disks?

We currently have a difference of opinion in our shop (or perhaps experience) relative to the practice of reseating array disk drives as a first step if they are in a failed state/amber status light is on.

I've been told in the past by HP technicians that it's hard on disk drives to pull them out and reinsert them if power is on to the array and drives. Not only that but I've been told it shortens their lifespan if you do this. Because of this I've made it a practice to reseat drives with power off to the disk array whenever possible. Needless to say, this can be a hassle and worse if a potential remedy has to wait until downtime can occur.

I have peers that say this is ridiculous and that if a disk drive can't handle any amount of online hot swapping, they're not of good quality.

Who's right? Does HP have an official position, customer advisory, etc. that addresses this question?
Uwe Zessin
Honored Contributor

Re: Best practice for reseating array disks?

A hot-plug disk drive and storage array are designed for replacement under power. If you power off before reseating a single disk, you put the entire array with all its disk drives under a power-cycle stress (which includes spin-down and spin-up of all disks)!

On the other hand - disk drives and backplane connectors cannot withstand 'any amount' of swaps. I don't have current numbers, but the old StorageWorks 1 carriers were designed for about 200 plug cycles.