How to add additional larger drives to RAID-5 array on PERC 4e/Di which is also System Drive C:?

Hello Steve

The short answer is no, but there is another way.

The basic rule about a virtual disk is that the amount of space used on a drive is equal to the smallest drive in the array, so if you have 3 drives(1TB, 500GB, and 250GB) it will only use 250GB of each of the drives. 

There is a way that you can rewrite the metadata on the drives. There is data written on each drive in the array that has the array configuration. If we delete that data and then repopulate it without deleting the data on the disks then the new space will be available for you to use. This method is called a retag. Basically, you delete the array(meta data) and then recreate the array. When you do this you need to be sure to not initialize the array. This(initialization) is similar to a low level format and will erase the data on the drives.

I highly recommend that you back up any important data before attempting this.

• Swap the 33GB HDD's out one at a time with the 279GB HDDs. Make sure each one completes rebuilding and the array is optimal before swapping out the next one.
• Make sure all hardware is up to date(BIOS, BMC, Controller firmware, etc)
• Make note of the array configuration(RAID level, stripe size, volume name, ETC)
• Delete the array
• Create a new array with the same 3 drives that were in the previous array. Do not attempt to add additional drives to the array during this step.
• Make sure that the specifications of the array are identical to the previous array(RAID level, stripe size, volume name, ETC)
• The array size can be different. I think the volume name can also be different, but don't risk it.
• IMPORTANT - Do NOT initialize the array. You will likely get a popup after creating the array asking if you want to initialize the array. If you do this it will wipe the data off of the drives.

After you complete those steps you can use Disk Managment in 2008 to expand the partition size. For 2003 you will need to use a 3rd party utility to expand the partition.

The suggested method is to backup, recreate the array with the new disks, and then restore from backup. The above method has a lot of possibility for data loss, so use it at your discretion.

Thanks

Let me just underscore the caution Daniel gave you ... a retag was intended to be a recovery method for arrays whose configuration was lost or corrupted.  When used in this scenario, you will see the full amount of the disks in the RAID array after a retag, BUT THIS IS ONLY A SIDE-EFFECT, NOT the intended result.  When done with different size disks, this will screw up the RAID layout on the disks, causing eventual failure of the array.

Without doing a retag, the suggested methods are:

1.  As Daniel said, backup/delete/recreate/restore with your larger disks.

2.  If you replace each disk with larger ones, the only thing you will be able to do with that space is create a second array across the disks.  This will be seen as a new "disk" by Windows, so it will need to be a separate partition/drive, meaning you will not be able to merge this space with that on "disk 0" (like expanding C:\).  So, you could then free up space on C:\ by moving data to the new 560GB D:\ partition.  This method can have more potential issues associated with it than configurations with a single VD across the disks, so it will be very important to make sure that the system firmware, including the RAID and HDD firmware is up to date to avoid them.

Here is the complete scenario of the system so we can all be on the same page.  I obviously need to get this right.

System Specs:  PowerEdge 2800, MS Server 2003, 4GB RAM, Dell Open Manage 6.3.0, PERC 4e/Di

Virtual Disk 0 consists of 33GB in slot 0, 33GB in slot 2, 279GB in slot 9 - RAID 5 (Logical disks C:, E:, both 33GB)

Virtual Disk 1 consists of 279GB in slot 3, 279 in slot 4 - RAID 1 (Logical disks D:, 279GB)

Slots 1, 5 & 8 are empty; I have 2 new 33GB drives and one 279GB drives in a box to be used as needed.

Went to Disk Manager and see that Disk 0 has two partitions on it.  C: and E:, both same size 33GB.  I thought that by using Partition Manager I could resize E: and extend C: into it making it larger.  This failed.  Guessing because of the 279 in slot 9 only being able to use the 33GB partition b/c of belonging to the VD0 RAID-5 array...

The C: drive obviously houses Windows Server 2003 on it along with a ton of other big apps, including Exchange 2003.  I can't muff this up!  If this was just a data array I wouldn't worry.  If something goes wrong with the array that the system is on, I'd have to reinstall the server, all the apps, including the Symantec Backup software, then hope to God that the data comes back.  Basically look for another job.  Sweating already thinking about this.

So, I understand that I need to find out the BIOS, PERC controller firmware version (which by the way Open Manage says is out of date but I can't find a newer version).  Green checks on all other components of the Storage section.

To point 2. above, what happens when I remove one of the 33GB and insert a 279GB?  Do I see a message that the drive is larger and what do I want to do with the balance of the space avail?  Is that where I assign a new drive to the "unused" part of it?  Then use a utility like Partition Manager to merge this new space?  What happens to the E: partition that already exists?  It has no data on it.  Does E: get deleted first, then proceed with the drive swapping?

Thanks for the fast tips thus far...

I've never used Partition Manager, so I can't say what issues there might be, but it is unlikely to be because of the "actual" size of the 300GB drive.  It is more likely that there was unsufficient free disk space on Disk 0 for PM to rearrange the data.  Is Disk 0 Basic or Dynamic?  Dynamic disks are generally bad, in part for reasons such as this.

What version does OMSA say is installed on your PERC driver/firmware?

"To point 2. above, what happens when I remove one of the 33GB and insert a 279GB?  Do I see a message that the drive is larger and what do I want to do with the balance of the space avail?"

No.  The RAID controller will happily take the 300GB drive and rebuild it in the place of the 36GB drive.  As long as it is at least as large, it will just assume that you put in the size you wanted.  It will not ask you what you want to do with the new/available space ... ever ... it will only do with it what you explicitly tell it to (Reconfigure in OMSA).

So ... you say the E: is empty ... what is E: for?  Do you need to keep it?  If you have 36GB drives, why is a 300GB drive in the RAID 5 (did you start rebuilding each drive with a larger one? :))?  On a hardware RAID controller, whatever you do to VD0 will not affect other VD's.

Another way to increase your storage would be to add drives to your RAID 5.  For example, you said you have two empty/unused 36GB drives.  You could Reconfigure your 3-disk RAID 5 to a 5-disk RAID 5, and expand your RAID 5 to 146GB (132GB); you could then extend your C: or D: drives to use this space, as it would be making Disk 0 larger.

"I've never used Partition Manager, so I can't say what issues there might be, but it is unlikely to be because of the "actual" size of the 300GB drive.  It is more likely that there was unsufficient free disk space on Disk 0 for PM to rearrange the data.  Is Disk 0 Basic or Dynamic?  Dynamic disks are generally bad, in part for reasons such as this.

How do I find out if the Disk 0 is Basic or Dynamic?

What version does OMSA say is installed on your PERC driver/firmware?"

PERC 4e/Di:

Firmware Version 5B2D
Driver Version 6.46.2.32
Storport Driver Version 5.2.3790.4021
Minimum Required Storport Driver Version 5.2.3790.4173

"So ... you say the E: is empty ... what is E: for?  Do you need to keep it?  If you have 36GB drives, why is a 300GB drive in the RAID 5 (did you start rebuilding each drive with a larger one? :))?  On a hardware RAID controller, whatever you do to VD0 will not affect other VD's."

I did not setup this server so I have no idea why the 3rd disk in the array was 279 with only 33 used.  Maybe he didn't have another 33GB?  I assumed it is the reason I have an E: logical available on Disk 0?  I can use it, but would rather have it's space for the C: drive.

"Another way to increase your storage would be to add drives to your RAID 5.  For example, you said you have two empty/unused 36GB drives.  You could Reconfigure your 3-disk RAID 5 to a 5-disk RAID 5, and expand your RAID 5 to 146GB (132GB); you could then extend your C: or D: drives to use this space, as it would be making Disk 0 larger."

This approach sounds tempting.  I have 1x 279GB, 2x 33GB and three open slots in the chassis.  How do you come up with the 132GB numbers?  If I add two 33GB drives to two open slots and add them to the VD 0 RAID-5 array, seems like all I'm doing is adding more redundancy for C:?  Trying to wrap my this.  I'd like to be able to use the extra disks if possible.

Steve

How do I find out if the Disk 0 is Basic or Dynamic?

In Disk Management (right-click [My] Computer, Manage), it will say Basic/Dynamic right below Disk 0, Disk 1, etc.

I assumed it is the reason I have an E: logical available on Disk 0?

No, the larger drive would have no effect on the partition sizes.  Whoever set it up simply created two partitions on the 66GB "disk", which is the RAID 5 VD0, each of 33GB.

I can use it, but would rather have it's space for the C: drive.

That larger drive will never be able to add space to your C: drive as is.

"Another way to increase your storage would be to add drives to your RAID 5.  For example, you said you have two empty/unused 36GB drives.  You could Reconfigure your 3-disk RAID 5 to a 5-disk RAID 5, and expand your RAID 5 to 146GB (132GB); you could then extend your C: or D: drives to use this space, as it would be making Disk 0 larger." This approach sounds tempting.  I have 1x 279GB, 2x 33GB and three open slots in the chassis.  How do you come up with the 132GB numbers?  If I add two 33GB drives to two open slots and add them to the VD 0 RAID-5 array, seems like all I'm doing is adding more redundancy for C:?  Trying to wrap my this.  I'd like to be able to use the extra disks if possible.

A 36GB disk actually has a little over 33GB of usable space.  Your 3x36GB RAID 5 is currently around 66GB of usable space on Disk 0, right?  RAID 5 uses one disk's worth of space across the array for parity data, meaning that 2/3 disks' worth of space can be used; likewise, 4/5 disks' worth of space can be used in a 5x36GB RAID 5 ... 4 x 33GB = 132GB.  By reconfiguring from a 3-disk RAID 5 to a 5-disk RAID 5, you are not adding more redundancy (you still have only a 1-disk redundancy), but you increase your storage capacity from 66GB to 132GB.

This would allow you to use your 33GB disks to make C: bigger, then use the entire capacity of your larger disks for some other purpose.

Sorry ... with the graphic, I forgot that you have two partitions on that disk.  For the purposes of the reconfigure, it changes nothing - hopefully you get the idea.  

The only thing that changes about this whole scenario having two partitions on Disk 0, is that you cannot extend C: directly into the Unpartitioned Space, as you can only extend into ADJACENT Unpartitioned Space, but many partitioning utilities (maybe Partition Manager) can rearrange data to make this work how you like.  Otherwise, you would have to first delete E: then extend C:.

To answer the Basic or Dynamic question, all the drives are Basic.

The E: partition was used for the page file and other utilities that previous admin had collected but didn't want to put on the D: drive.  I moved the page-file to D:, and now the E: drive is now avail for deletion.  A reboot will take care of the page-file move.

Now for the meat and potatoes if you will.

• Does it matter which slots I put the 2x 36GB drives in?  I've got them currently in slot 0:1 and 0:5
• If above placement is OK, then which options do I choose from below menus and in what order?

OK man.  I'm going to reboot server tonight to make the page-file move permanent.  I'll delete the E: drive start the Reconfigure tomorrow that and will plan on the partitioning next week when I have an open window again.

Will let you know how it goes!

Is there a reboot needed after the Reconfigure?

There is a chance.  Typically no, but several things can cause a reboot to be necessary.

Cool ... glad to hear it :)

Success!  I went ahead and did everything last night.

Reconfigure took about 3.25 hours.  Repartition was easy with Partition Manager.  Now have a ton of space and room for expansion if needed.

Thank you for all your help guys, especially theflash1932.

Warm Regards,

Steve

Let me know if I should start a new post for this but, I have Dell Poweredge 2850 and added 2 136G drives to my current 3 disk RAID 5 array using OMSA.  All disks say online now. However, the additional space is not showing up in windows disk management.  Did I do something wrong?