OVM Local Disk Tips

OVM Local Disk Tips

You must have at least two physical disks in your OVM server. Two partitons on
one disk will not work. OVM Server will claim the entire first disk for
installation. You can then use the second disk as local storage, if, and only if,
the second disk is completely blank. If there are any partitions of any type on
the second disk, it will not be recognized under OVM as a local disk.

Local disks are not supported by Oracle. Using local disks for anything other
than basic and preliminary learning of how to work with OVM with a limited
hardware inventory such as a couple of laptops or desktops, is a very bad idea.

Verify all partions are removed from 2nd non-OS local disk on OVM Server.
$ fdisk -l

On Ubuntu Linux, use sudo to prefix each command, as in:
$ sudo fdisk -l
(enter root password)

If your first disk is /dev/sda and your second disk is /dev/sdb,
use fdisk to remove all partitions on the second disk, /dev/sdb.
$ fdisk /dev/sdb
p(rint)
d(elete partition) 1, d 2, d 3, etc.
w(rite)
q(uit)

multipathd needs to be running on your OVM Server, even if no
multipath storage exists on the system.
     # chkconfig --list multipathd
     # chkconfig multipathd on
     # chkconfig --list multipathd
     # service multipathd restart

verify multipathd lists the local storage on your OVM Server.
     # multipath -ll
     # multipath -ll -v[1..3] (Verying levels of detail)

verify storage discovery works
     # storage_discover --infoDumpType=disk_XML

I run OVMM (OVM Manager) on a laptop with 4GB of RAM as a VirtualBox VM. Slow
but functional. YMMV.

On the OVMM OS (physical OS or VM), ensure iptables are disabled.
     # chkconfig --list iptables
     # chkconfig iptables off
     # chkconfig --list iptables
# service iptables stop

Rescan the Physical Disks on the OVM Server from OVMM.

Create repository on local disk per Appendix C of OVM Quick Start Guide.
Happy learning.

"Create repository on local disk per Appendix C of OVM Quick Start Guide."

That only used to be true. It got dropped in the 3.0.3 version of the doc. To find Appendix C, you must look in an older version of the guide, ovm3-quick-start-guide-wp-516656.pdf, at: http://www.oracle.com/technetwork/server-storage/vm/ovm3-quick-start-guide-wp-516656.pdf

"Local disks are not supported by Oracle"
Untrue. See above mentioned doc.


I found all that was necessary is to partition your local array in your RAID controller into two or more virtual disks (BEFORE installing the VM Server.). 
Only present one of the virtual disks to the VM Server install. The other(s) will then be available to use as local storage within the VM Manager.
Of course the first time through the server setup I got it wrong... but that's history now...

Hello.. I've tried multiple times too, to get the local disks to be discovered, but having no luck.

Hardware.. IBM x346 server.. 2 x 73gb drives (mirror)... 4 x 146gb drives (raid 5).

Install OVM Server 3.0.3 server and it installs to /dev/sba no problem... It trys to install the / to the /dev/sdb, but I remove it and put it back on /dev/sba, so that nothing but Free Space is showing for /dev/sdb.

After it's all installed/rebooted, etc.. I go to the OVM Mgr (3.0.3 build 240) server and discover the new box.
It sees the oelvmibm02 server. I'm able to add it to the ibm-pool, and when I discover Physical Disks.. nothing shows.

I've ensured that iptables is OFF for the vm mgr server.

I've looked at the multipathd service on VM Svr.. it's running.
However, when I issue the command multipath -ll 
here is what I get:
DM multipath kernel driver not loaded

I've reinstalled OVM Svr 3.0.3 multiple times on this box, with different configuration trying to get it to recognize the 2nd array so I can have a repository, but nothing seems to work.

Any ideas on what to try next? I'm all open for suggestions.

don't know if this affected others on this list but this one caused me to not see local disk

6.4.3. Local SAS Hard Disks Not Supported for Storage
If you use an Oracle VM Server with local SAS hard disks installed, empty disks of this type are not discovered in Oracle VM Manager and therefore cannot be used as local storage. This is caused by the fact that local SAS disks are not associated with a (local) storage array. SAS hard disks can therefore only be used for installing Oracle VM Server on them; they cannot be used for storage repositories, server pool file systems or raw LUNs as virtual machine disks.