Snapshots

Citrix XenServer 5.5 - First impressions

I had decided to try out Citrix Xen Server at home since i work a lot with vmware during my working week and felt like a change. It all seemed well… That is until i had to deal with snapshots. I suppose i have taken for granted almost all other virtual host software that provides a simple “revert to snapshot” option. From what i can tell this is totally absent from Citrix XenServer 5.5.

Troubleshooting - Time Slider (zfs snapshots)

1. snapshot complains about no access to cron

This problem i came across was after i was playing with crontab. It looks like the zfs snapshot service uses an account called “zfssnap” and if it doesnt have access to cron then it will have issues creating / checking snapshots. Check the file /etc/cron.d/cron.allow and ensure that “zfssnap” is in there. The issues i had looked like this in the log…   (check the logs via the log file viewer)

ZFS - Creating snapshots

There is some funky ways of modifying the default “time slider” services to do the work for you, but i like a bit more hands on. Generally so i know what is happening in the background, but the time slider can be sometimes overkill creating snapshots every 15 mins if not configured properly.

On a side note i’ve yet to get my head around the SMF stuff properly… Anyhow onto creating snapshots.