Friday, January 25, 2008

Why does VMware crash during startup from ntfs-3g?

VMware tries to use shared writable mmap for paging files from version 5.0 but it can't detect that it's not yet supported.

Workaround: Set "mainMem.useNamedFile=FALSE" in the .vmx file. It will disable paging files and VMware will work fine, often with much better performance.

Status: This has been worked one in the kernel and FUSE for three years. The solutions is complex and several experimental patches are available. VMware has also fixed their virtual machine recently.

Friday, January 11, 2008

"No space left on device" error from Xen

xenstored database may get corrupted sometimes and upon vm startup it would give a very misleading message like.

# xm create /etc/xen/win2k3
Using config file “/etc/xen/win2k3”.
Error: (28, ‘No space left on device, while writing /local/domain/0/backend/vbd/
18/768/online : 1′)

The workaround is documented here. In short, you have to do the following:
  1. Stop xend "/etc/init.d/xend stop"
  2. Kill xenstored as the above script does not shut it down (I also killed xenconsoled, just in case)
  3. Delete all tdb file from /var/lib/xenstored/tdb*
  4. Start xend
  5. Attempt to start your vm.
  6. If you see the following error just reboot the machine.

    # xm create /etc/xen/win2k3
    Error: Device 0 (vif) could not be connected. Hotplug scripts not working.
  7. After reboot everything should be fine.