12h AutoRaid hot swapable drives?

[John Love_3]

I've just gotten 5 new 36GB disks to add to my array (which has 8 9.1GB drives now) I'm just wondering if I can add the 4 new drives and configure the array why it's running, or do I have to shut down the system and the autoraid before I put them in?

[Insu Kim]

You can add disk drives with "Auto Include" enable while AutoRAID is working.
If Auto Include is disabled, you have to manually include them via SAM or STM (Support Tools Manager).
You can check the current status of Auto Include through SAM or in the front panel.

One thing that you have to be careful is to add disk modules step by step, that is, insert a disk module and see if it's enabled.
And if it does, repeat the procedure for the next disk module.

Do not install four disk drives on the box at the same time.
If you do, you might be in trouble.

Regards,

[Insu Kim]

One more is,
If you put the disk modules in the box with power off, AutoRAID will not recognize them at all.

[A. Clay Stephenson]

Add the disks one at a time eith auto-include enabled and everything will go well. Just let the 12H finish its operations before adding the next drive. You will probably see the array begin balancing. It's best to let that operation completely finish (which could take
a bit of time) before going on to next drive.
I note that you bought 5 drives. How do you replace one of the 9GB with a 36? I would do this this but pick any old drive and remove it
while the array is up. Wait just a bit and insert the new drive and your done.

[Bill McNAMARA_1]

Yes, everything more or less that HP sell with a handle is hot plug!
The autoraid controllers, fans and power supplies are... but they are all N+1.
ie you got N+1 you need N for the array to function.

When inserting disks watch out for performance decrease during the time the array will move data between raid levels. ie BALANCing on the control panel. You may want to do it later on at night when the filesystems on the autoraid are less used.

Make sure too you add disks in double so that the full capacity of the disk is taken into account. ie: if you have 8 9G drives and you add in 1 9G and 1 18G drive, the effective capacity you just added is 2 9G drives.
Adding 2 18G drives is fine.

Note too that active spare requirements will increase. The biggest disk that can fail now is 18G... and rebuild times will be longer too.

Later,
Bill

[John Love_3]

What I plan on doing is reconfiguring all the drives in the array, once I back it all up.
Currently the disks are not configured properly for RAID 5, and I need that for safety's sake.
So, I'll be adding 4 36GB drives with the original 8 9.1GB drives. I'm going to create several logical drives of about 20GB

If there is anything else I need to be careful of, please let me know.

Thanks for all your help.

[A. Clay Stephenson]

John, believe it or not what you don't want to do is configure your AutoRAID for Raid 5. You don't have any explicit control over it in any case. The ideal way to run a 12H is no more than 60% configured (and a little less is better) so that all data is in RAID01. This dramatically increases performance at the cost of space utilization. When I say unconfigured I mean intentionally leave space not configured as a LUN. The very best performance
is obtained when each volume group is comprised of two identically sized LUNS and then each logical path is striped (64K stripes for VxFS) across the two LUN's.
The idea is for LUNa's primary scsi path to be through controller X (alternate Y) and LUNb's
primary scsi path to be through controller Y (alternate X). This way both external SCSI buses are fully used and I/O goes up very noticeably. Note that your data is just as well protect at RAID01 as RAID5 but fewer physical I/O are required. Not that you can do this but a slight performance gain is realized when all the disk modules are identical.