Adding HDDs to Servers

[jandkdavidson]

We have two HP ProLiant DL380 G6 servers, each in a RAID 5 configuration with ESX 4.  We are using vSphere on these two servers, and the vSphere controller is at 4.1.

This is a testing environment, so it's not necessary to have the fastest or most reliable setup.  More space is for the most part the determining factor.

We would like to add more HDDs:

1.  Can you just plug the HDDs into the existing bays and let the RAID controller take over (restriping, etc.)?

2.  If not, is our only option (if we want to keep the current VM's) to backup the existing vSphere setup, add the HDDs and rebuild the RAID array, and then recover the data from the backup?

3.  If the backup is the way to go, what recommendations do you have for backing up vSphere?  Cheapest would be the way to go here (what software and external drive?).

4.  Can you create one RAID5 array across both servers instead of two separate RAID5 arrays? (I don't like this option since it will only give us 300GB more space with less reliability, but it's been requested)

I've searched quite a bit on this site and didn't see much on this particular confuguration, so any help would be much appreciated.

Thank you!

[DSTAVERT]

You can add disks but you must use the Smartstart CD to change the array. It can add the new drives without loosing the contents however you would be very unwise if you didn't completely clone your existing VMs to another location just in case.

Just a suggestion but you could consider shared storage. A spare or older server could be used for datastore storage for both servers. Put all your drives into the spare server. You can use a standard LINUX install and set up an NFS server or use FreeNAS or Openfiler Software to create an NFS or iSCSI storage server.

[a_p_ · Accepted solution]

1. You can add additional disks to a RAID set, you can even change the RAID level (if needed) using the Array Configuration Utility (on the SmartStart CD) However these functions are usually only available with BBWC (battery buffered cache) on the RAID controller.

2. You should always have a backup!

3. You may take a look at ghettoVCB

4. No, you cannot span the RAID across two physical servers.

André

[a_p_]

... and remember, the maximum disk/LUN size for ESX(i) is 2 TB minus 512 Bytes. Depending on the number and size of the disks, you may better split the RAID into several smaller logical volumes!

André

[jandkdavidson]

We'll have just around 2TB of storage per server, so I'll double check that.

Thank you for the info!