Difference between revisions of "Checking for swappers on XenServer"

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(New page: This article will outline the steps I take to check for swappers on my XenServer and XenClassic stepups. ==XenServer== * Log into the huddle the host in question is located in * Log into ...)
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Revision as of 11:04, 22 July 2013

This article will outline the steps I take to check for swappers on my XenServer and XenClassic stepups.

XenServer

  • Log into the huddle the host in question is located in
  • Log into the host the slice/instances is located on
  • Run iostat to check for any swappers on this host:
iostat -xkd 1
  • If swappers are found, cat the device of the slice to get its minor number:
cat /sys/block/tdk/dev  # returns something like: 1234:20
  • Get the UUID for this slice
tap-ctl list | grep minor=20
  • Check if this slice is a "swap" partition (make sure it is _not_ a root partition!):
xe vdi-list uuid=xxxx-xxxx-xxxx-xxxx
  • Check to make sure no other tasks are currently being perform on this host
xe task-list
  • Now force a reboot
xe vm-reboot --force name-label=slice01234
  • Check that the slice has actually rebooted:
xe vm-list name-label=slice01234 params=start-time
  • Verify that the output from the last command is within the current timestamp
date

That's it! You can successfully killed a swapper and brought the slice back up to a normal load.

XenClassic

This is how you do the above on a XenClassic setup.

  • Log into the huddle the host in question is located in
  • Log into the host the slice/instances is located on
  • Run iostat to check for any swappers on this host:
iostat -xkd 1
  • If swappers are found, list the device mapper for this slice:
ls -l /dev/mapper/ | grep ' 20 '
  • Now "destroy" that slice (we are not permanently destroying this device, that's just the terminology):
xm destroy slice01234
  • Finally, re-create this slice (this takes information from a configuration flatfile found under /etc/xen/slice01234):
xm create slice01234

That's it! You can successfully killed a swapper and brought the slice back up to a normal load.