Archive for the ‘vSphere’ Category

“Cannot change the host configuration” when adding an existing VMFS

01/07/2010 Leave a comment

Today i have experienced a weird problem with vCenter. I was adding an existing VMFS lun to our vSphere cluster. Adding the VMFS to the first node worked flawlessly but all other nodes fails with the error “Cannot change the host configuration”

After some googling i found out that i was not the only one with this problem. It seems to be a bug in vCenter. You can work around this problem by connecting to the ESX server directly with the viclient. Adding the VMFS works perfect this way.

also see:

Categories: VMWare, vSphere

Changing the block size of the local VMFS during install..

12/11/2009 Leave a comment

Finally someone (PatrickD) found out a way to change the block size of the local VMFS during install. I remembered i had tried to increase before. Nowadays i create a dedicated VMFS for the service console.


There isn’t an easy way of doing that right now. Given that a number of people have asked for it we’re looking at adding it in future versions.
If you want to do this now, the only way to do it is by mucking around with the installer internals (and knowing how to use vi). It’s not that difficult if you’re familiar with using a command line. Try these steps for changing it with a graphical installation:

  1. boot the ESX installation DVD
  2. switch to the shell (Ctrl-Alt-F2)
  3. ps | grep Xorg
  4. kill the PID which comes up with something like “Xorg -br -logfile …”. On my system this comes up as PID 590, so “kill 590”
  5. cd /usr/lib/vmware/weasel
  6. vi
  7. scroll down to the part which says “class vmfs3FileSystem(FileSystemType):”
  8. edit the “blockSizeMB” parameter to the block size that you want. it will currently be set to ‘1’. the only values that will probably work are 1, 2, 4, and 8.
  9. save and exit the file
  10. cd /
  11. /bin/weasel

After that, run through the installer as you normally would. To check that it worked, after the installer has completed you can go back to a different terminal (try Ctl-Alt-F3 since weasel is now running on tty2) and look through /var/log/weasel.log for the vmfstools creation command.

Hope that helps.

Categories: VMWare, vSphere Tags: ,