vSphere Service Console and Disk Partitioning

Everyone at this point should be aware that the Service Console is now located in a vmdk on a VMFS partition.  The Service Console vmdk must be stored on a vmfs datastore and the datastore must either be local stoage or SAN storage that is only presented to the one host.  So I guess no shared vmfs datastores to house all the Service Consoles…….  The next question I had about the new service console was the /boot partition.  Where is it and how is the server bootstrapping?  Well I can’t say I have totally gotten to the bottom of this yet but I have discovered a few things.  When digging into scripting installations of vSphere I first looked at the disk partitioning which sheds a little light on the boot process.  Here is what the disk partitioning portion of the script looks like:

part /boot –fstype=ext3 –size= –onfirstdisk
part storage1 –fstype=vmfs3 –size=30000 –grow –onfirstdisk
part None –fstype=vmkcore –size=100 –onfirstdisk
# Create the vmdk on the cos vmfs partition.
virtualdisk cos –size=8000 –onvmfs=storage1
# Partition the virtual disk.
part / –fstype=ext3 –size=0 –grow –onvirtualdisk=cos
part swap –fstype=swap –size=1600 –onvirtualdisk=cos

Notice the “onfirstdisk” switch at the end of the first three partitions.  The /boot, a vmfs partition, and a vmkcore partition are all on the physical disk.  Notice the swap for the service console is located inside the vmdk.  Notice the creation of the service console vmdk disk.  “virtualdisk cos –size=5000 –onvmfs=storage1”.  To account for this change VMware has added some new configuration option for scripting the installation of the COS.  Next you’ll notice the  the creation of the / and swap partitions fort the COS utilizing the “onvirtualdisk=cos” switch.

I’m still working on and discovering some of the new ways to do scripted installation with vSphere 4.0.  I though this little tid bit would be helpful to those of you wondering how the COS ties in to the whole mix.  A few interesting things about this new method.

No need to specify the actual device, however I would be very cautious about the –onfirstdisk switch if SAN LUNs are present on the server.  I would take extra precautions to ensure that no SAN LUNs are connected.  There really are not any best practices around this configuration yet so there are a few things that I think need to be determined.  If you were planning on running VM’s from the local VMFS should you create multiple VMFS partitions and have one solely for the COS.  I almost think it would be beneficial just for the logical separation.  Well I will be digging a bit deeper into this but would love to hear others views on the COS and how they plan to deploy and why.  So please comment and let me know what you think.

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