RAID 0 to RAID 5

[Alejandro Benitez]

Hi!
I have two 9.1Gb disks on a RAID 0, LH3, Internal Netraid.
I have problems on a disk and I want to convert this RAID to a RAID 5 (using NetRaid Assistant and using a new 9.1Gb disk) level and then change the disk that report problems with another new one.

It is posible or I am dreaming ?

Thanks,
duende@adinet.com.uy

[Ted Ellis_2]

with only 2 disks you are not going to get the normal benefits (lower overhead) with RAID 5. With 5 disks, the error striping that happens to protect from a disk failure requires 20% of the total LUN.. or a single disk worth of space. You might as well configure the disks as a mirrored pair (RAID 1) than RAID 5. That or consider adding additional disks to the LUN to have more than 2...

Ted

[Greg Carlson · Accepted solution]

Alejandro,

You can add another hard drive and migrate to a Raid 5 after adding the hard drive. However what kind of errors are you having on one of your hard drives? Beware that when you are adding capacity and changing from a Raid 0 to Raid 5 the server will be rebuilding data across all of your hard drives and not just the newly added hard drive. If you are have a bad hard drive you may fail the rebuild and have to do a fresh install and restore from backup so make sure you have a known good backup before doing this.

Inside Netraid assistant once you have added the new hard drive just highlight the logical drive and the READY drive. Then click on Logical drive on the toolbar and change config to change your raid level.

Good luck and backup first!
Ciao,
Greg

[Alejandro Benitez]

ok, the disk is failed, because is the second time with the red lights on the front.
I forced to go online on the netraid tool (CTRL-M).

We are going to buy two new disks and with this change, RAID 0 to RAID 5 I can add tolerance to the system and change the failed disk.

Its Novell 5 and maybe there's another way to mirror the RAID 0 from the NWCONFIG tool or similar.

Thanks,
Again

[Terri Harris]

It is not recommended to configure software RAID on top of hardware RAID. Use one or the other but not both.
What about converting the existing RAID 0 to a RAID 1? This will you give a hardware mirror. You need exactly 2 drives to do this. A RAID 5 requires a minimum of 3 drives. So to have a RAID 1 and a RAID 5 would require 2 + 3 drives minimum.
If you are looking to expand Novell volumes, there are limitations based on how the initial Netware install partition was created (mainly the size). For more information, email HP Netserver support at:
NetSrvTech_Support@hp.com

[Michel M.]

Alejandro,
The response from Greg was the right way to do.
But, I understand you have a failed drive, so it's too late to save your data... You will need to restore from a good backup.
If you buy 2 new disks, you will have 3 healthy drives available. So keep the idea of building a hardware Raid 5 from scratch, and restore your datas. Don't use any software Raid, it is not a good solution.
Good luck,
Michel

[Laurin Jeffrey]

I also have an odd question.

Is it possible to set up 2 drives in a Raid 0 configuration, then later add another 2 drives and mirror the original 0 config onto this new config to create a 0+1 array?

Can this be done without losing the data on the original 2 drives in the 0 array?

Essentially I want to set this system up, but don't have the cash for 4 drives right now. So, I want to buy 2 and start with the 0 array, which is not quite so safe. But, when more money becomes available, I would like to buy the other 2 drives and create another 0 array. Then mirror the original array to the new array and create a safe mirrored setup.

Help!

[Terri Harris]

With the HP NetRAID controllers there is not an option to mirror a RAID 0. If you have enough free disk space (at least 9 GB) I would recommend converting the RAID 0 to a RAID 1. Then you can swap out the problem drive.
The other option is to add a 3rd drive and convert the RAID 0 to a RAID 5.