Yellow Bricks

by Duncan Epping

Standalone vSphere hosts and the local VMFS

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On twitter @lamw just asked a question which triggered me to blog it cause I expect this is something more people will run into sooner or later.

Anyone know if you can change the default VMFS block size in ESX4 during interactive installation?

This is something that I also ran into personally a couple of weeks ago. If you install ESX 4.0 with the defaults a large VMFS volume is created that fills up the disk. This VMFS volume has a default block size of 1MB which means a file size limit of 256GB.

In the setup there’s currently no way of changing the block size. (If I’m wrong please leave a comment.) The only way to avoid this is to create two VMFS volumes. The first one will need to be created during the installation and will be the volume on which the Service Console VMDK resides. The second VMFS volume should be created after the installation and will be hosting the VMs. Although it does sound like an unnecessary step I personally think it is a good approach. This way the chance of filling up(snapshots) your VMFS partition which hosts you Service Console is very slim.

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Comments

  3. Arun Raju says

    Duncan,

    Is there an option to specify the Block Size using Scripted Installation method ?

    Some of the users raised this query in
    Experts-Exchange Forum too.

  8. goingvirtual says

    Hi Duncan. Good article,

    Ive started creating 2 VMFS partitions, one for the console and one for virtual machines as you noted.

    After the install I always delete the second and add it back in using vCenter so the partition is aligned. Looking back on VI3, VMFS partitions created during the install by default are not aligned. I know most people dont bother about this with local VMFS partitions but I like to do what I can to get the best performance.

  13. deobfuscate says

    To my knowledge there is no way to change the default block size during the installation. I had this problem when I was trying to setup a client’s ESXi environment and wanted a bigger block size.

    Furthermore I had problems deleting the VMFS volume after installation and recreating the volume with a larger block size.

  14. Willem says

    A reply to an old post.. but after fighting with this a bit on vSphere (running the GUI and Textmode install) I’m wondering what the correct procedure would be to setup two vmfs volumes while installing?

    quoting Cody: ‘So while one may not be able to do it directly from the installer, what is to stop you from popping out to a different terminal and running the fdisk command and setting this up by hand?’

    In what order do you have to do this and is it also necessary to create a vmfs file system?

    Thanks for any extra info, with VI3 this was quite easy, but vSphere does present a (little) new challenge here. 😛