dc1743
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Best option to expand capacity on PERC H700 Raid5 array in R710?

I have a R710 with 6 300GB LFF SAS hard disks occupying all the drive slots.   These drives are connected to a PERC H700 which has them configured as a Raid 5 array with one virtual disk using all the capacity (~1394GB).  The virtual disk is partitioned into two, 40GB for Server 2008 and the rest for data.

I need to expand the capacity of the virtual disk without flattening the box and rebuilding and am looking for options.  I confess I have limited server experience Dell or otherwise.  

Could I for example, replace one drive with a 600GB LFF SAS disk, allow the rebuild to take place, and then repeat for all the other drives one by one.   Would I then be able to expand the virtual disk into the free space?  I have seen some reference to the Replace Member Disk option but am not sure if it is applicable to my situation.

Or is there a quicker offline way to replace the 300GB disks with 600GB disks but still retain the virtual disk?

Please can anyone advise if there are any better or alternative options?

Thanks for reading.

Richard

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theflash1932
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Re: Best option to expand capacity on PERC H700 Raid5 array in R710?

Your only two options are:

Slower:

Replace each drive individually, allowing each to completely rebuild before replacing the next one.  Once you are done, you will have around 2.8TB of available RAID space, BUT there is no way to integrate this new 1.4TB of space into the existing 1.4TB of RAID space.  The only thing you will be able to do with it is create a new RAID 5 VD across the disks.  This will give you a new 1.4TB "disk" to use in Windows.  As it will be seen as a separate disk by Windows, you will not be able to merge it with existing partitions.

Faster:

Backup, replace drives, create RAID 5, restore.

One thing to keep in mind:  Windows can only see a >2TB disk IF it is formatted as a GPT disk (as opposed to MBR), however, Windows cannot boot to a GPT disk unless the OS is 64-bit AND installed in UEFI mode.  So, depending on your backup/restore method, and your original installation choices (MBR/GPT, 32-bit/64-bit), this method may or may not do what you are hoping to accomplish.  It may require a reinstall of the OS, then a file-level restore.

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dc1743
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Re: Best option to expand capacity on PERC H700 Raid5 array in R710?

Faster:

Backup, replace drives, create RAID 5, restore.

One thing to keep in mind:  Windows can only see a >2TB disk IF it is formatted as a GPT disk (as opposed to MBR), however, Windows cannot boot to a GPT disk unless the OS is 64-bit AND installed in UEFI mode.  So, depending on your backup/restore method, and your original installation choices (MBR/GPT, 32-bit/64-bit), this method may or may not do what you are hoping to accomplish.  It may require a reinstall of the OS, then a file-level restore.

Thanks for the advice provided so far.
What would you advise is the best way to back up the virtual disk so that it can be restored to a new larger raid 5 array? (e.g. is there a way I can dd the virtual disk assuming there is a linux disc with the appropriate drivers)
Can the new array be created within the raid controller bios?
What tool do I use to restore the backup without an OS existing on the new raid.
Thanks again.
Richard
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theflash1932
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Re: Best option to expand capacity on PERC H700 Raid5 array in R710?

Are you using 2008 32-bit or 64-bit?  Did you install in UEFI or BIOS mode?

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dc1743
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Re: Best option to expand capacity on PERC H700 Raid5 array in R710?

The OS is 64 bit but was pre installed prior to us obtaining the server.  I can see from disk management that the partitioning scheme is MBR and there is no Microsoft Reserved Partition so I presume it was installed in BIOS mode.

Taking your previous comments on board I would look to expand the existing VD to 2TB and create a new VD for the remaining space.

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theflash1932
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Re: Best option to expand capacity on PERC H700 Raid5 array in R710?

I'm pretty sure (although not positive) that restoring an OS installed in BIOS mode, will not boot in UEFI mode - there may be some method or hack around it, but ... just not sure.

Now, there is no way to "expand" the existing VD to 2TB ... if you create a second VD, it will be the same size as your original.  You will end up with two 1394GB "disks" in Windows, but at this point, that is probably your easiest option.

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