LH3000 U3 - NetRAID-2M - increase RAID5 without adding disks?

[Mark Bulgier]

Hello, not sure if what I want to do it possible. I had 3 x 36 drives in a RAID5, then replaced each drive with a 73 gig drive, one by one letting the array rebuild each time, so now I have an optimal 3 x 73 RAID5. NetRAID assistant still sees the logical drive as 70 GB. How can I use the extra space?

Adding it to the existing logical drive would be my first choice, but I will accept having to make a second LD if necessary. The existing LD contains my operating system.

I did this recently on a newer HP ML370 G4 with 642 RAID controller, it was easy. So I just jumped right in on the old Netserver. Thanks for any advice, or good or bad news - give it to me straight, I can take it!

[Sean T. Craig · Accepted solution]

Hi Mark,

I don't believe you can do this on the NetRAID cards. Check disk management and see if there is unallocated space at the end of the disk in question. If there is space, you can expand an extended partition using diskpart.exe, otherwise, the only way to use all the space is by recreating the array clean on the 3x73GB drives. Here's how I would do it:

1. Record all logical drive parameters (you will need them later)
2. Revert to your original configuration (i.e. replace one drive at a time and let it rebuild back to an optimal state)
3. Put the 3 new 73GB drives in the other 3 slots and create a new RAID-5 array (use the same LD parameters recorded above)
4. Clone everything from DISK0 onto DISK1 (Norton Ghost is my personal favourite)
5. Down the server and use NetRAID Express Tools (M at startup) to clear the config and recreate the second RAID-5 array (as the only array) using the same LD parameters.
*** EXTREMELY IMPORTANT ***
DO NOT INITIALIZE THE LOGICAL DRIVE - IT WILL DESTROY ALL DATA IF YOU DO
6. From this point, you should be able to use diskpart.exe to expand your extended partition. If all you have is a primary partition, you can use the additional space to create a new extended partition.

Hope this helps,

Sean T. Craig Sr. C.E.T., M.C.P.

[Mark Bulgier]

Sean, thank you for replying. I am awarding the points because what you describe sounds like it would work. I'm not going to try it though because it sounds like too much effort, and I don't really need the disk space! (The other 9 slots are occupied by an 8-drive array and a global hotspare). Your solution is very clever though!

[e4services]

Sure, you can extend/expand your exist RAID logical drive through the NetRAID controller. You still will not have the space available to the OS until you partition it

[Mark Bulgier]

e4services, Please explain, what is the command to issue to extend/expand? Would this be done using NetRAID assistant or some other interface? The only option I see in NetRAID Assistant is to add more disks, not extend/expand on the existing disks.

I would be grateful for any specific steps to take.

[Sean T. Craig]

Hi Mark,

I think what e4 is referring to is related to the first paragraph in my first post; check disk management and see if there is any unallocated space. I have seen this recommendation before on the forums but have been unable to verify if this is even possible with the NetRAID Controllers. If you call HP, they will tell you that you cannot; when you replace the smaller drive with the larger drive, it will only use the capacity of the smaller drive and the additional space is not recoverable. I will try it myself, however, as soon as I get some time.

Good Luck,

Sean T. Craig Sr. C.E.T., M.C.P.

[Sean T. Craig]

Hey Mark,

Sorry it took so long but I finally had a chance to try this.

If you replaced the 3x36GB drives one by one, when you go into the NetRAID Express Tools (M) and select Configure-->View/Add/Delete Configuration, it will ask you to accept the new Logical Drive parameters for the leftover space. Granted, this will be a separate logical drive, but you could then partition/format that space from Windows Disk Management.

Unfortunately, the only way to make that space part of your existing LD is to reconfigure, but this isn't a bad alternative.

Let us know how it goes,

Sean T. Craig Sr. C.E.T., M.C.P.

[Mark Bulgier]

Sean, that is very cool of you to do that research for me. Now I have to try it, so your work will not have been in vain! I had started putting the 36 gig drives back in, to utilize those 73s elsewhere, but have only gotten the first 36 of three back in and rebuilt, so it won't be hard for me to backtrack (again!) and try your method.

So the old NetRAID is more advanced than I thought! Wish they'd documented that feature (or maybe they do somewhere and I missed it), but in this case I'll settle for something that just works.

You, and this forum, are a credit to IT.

[Mark Bulgier]

Yep, it worked, case closed. Thanks again.