Smart Array 431 Mirroring

[Paul_260]

I have an idea and was wondering if anyone can confirm this.
Is it possible to have a Raid 1 hot pluggable, remove a drive put in another one to maintain the Raid 1. Use the drive that I remove as an image drive so to maintain a zero downtime. If that works, I want to repeat this process every time I do a system upgrade. I would remove one of the drives put the spare I had previously removed and have the Active drive over write the drive I just put in.
Thanks
Paul.

[Patrick Rouse]

If you have a RAID 1 Array and one drive fails you simply remove the failed drive and replace it with a new empty drive. Zero downtime, no image drive needed.

I'm failing to see why you want a spare w/ data for a RAID 1 Array. RAID 1 array's do not see degraded performance with one failed member, there's just not any redundancy.

[Paul_260]

My intention is to have a " Hot Copy" of the Os in a perfect state. If we ever have a crash, or some sort of disaster, we could take the drives out of the server and put the " Hot copy" in and have the system back up in minutes.
I want to keep the Raid one just duplicate one of the disk from time to time and use the duplicate as a form of disaster recovery.
Sounds a little better than imaging but will the technology allow me to do this.

Thanks
Paul.

[Terrence Holt]

Yes, you should be able to do this. This approach is secondary to having a "snapshot" feature on the filesystem. If you have a RAID-1 and you are performing an upgrade you should be able to do the following:

- Pull Disk 1/1 and store in a safe place
- Perform the upgrade
- If OS dies because of the upgrade you should be able to put disk 1/1 in the 0/1 position and tell the system to boot from it.

You asked if you can move the RAID-1 to another system. The RAID info is stored on the disks so as long as you at least have a SMART raid controller and similary hardware you can do this as long as you keep the order of the disks the same.

[Paul_260]

So does the 0/1 position has control over version of disk. Can it tell which is the newest copy of the disk.
SO what is the best way to keep an upto date copy of the OS withoug the imaging software?

Thanks again.
Paul.

[Colin_29]

Hi Paul,

This is exactly what I do on my mirrored systems and it works fine.

The only issue may be with warranty. You will need to swap the drives on a regular basis to keep your "on the shelf" drive up to date. I was once told by a Compaq specialist that the drives record, on board, their number of hot swaps and that any more than three will invalidate the warranty.

This kind of makes sense because, especially with the higher rpm drives, when you remove one completely without giving it time to spin down, you can damage the bearings. They have a real gyroscopic effect, we were shown this on a course once.

Since then I have heard contradicting reports about warranty replacements, and HP won't going to tell you because they don't want to encourage you to break drives.

Colin