Tools for XenServer Troubleshooting: http://blogs.citrix.com/2011/05/06/tools-for-xenserver-troubleshooting/

How to Collect Diagnostic Information for XenServer: http://support.citrix.com/article/CTX125372

Helpful XenServer Commands: http://support.randomsolutions.nl/432213-Helpfull-XenServer-Commands

Try booting with the 'Fallback' kernel and look for clues in the boot messages.

Type fallback or fallback-serial at the boot: prompt.

See also RAID Metadata Removal

If you are installing to disks that previously had been used in RAID configurations, you may get a kernel panic (hang on boot).

You probably won't see the kernel panic (hang on boot) until after installing SP1 (XenServer 6.2).

http://xenserver.org/component/easyblog/entry/xenserver-root-disk-maintenance.html?Itemid=179

Check disk space:

df -h | grep "/$" | head -n 1

Looking for files bigger than a given size (specify path and size):

find / -mount -type f -size +20M -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'

You can pretty much ignore anything in /var/run/sr-mount/ as it's not on the local filesystem.

Take special care when using wildcards with the rm command!

The first step might be to delete all files such as downloaded patches from /root:

ls -al /root
rm -rf /root/*

Delete rotated log files:

find /var/log/ -type f -name *.gz -exec rm -f {} \;

Delete applied patches:

Works pool-wide if run on the pool master server.

for i in `xe patch-list --minimal|tr "," " "`;do xe patch-pool-clean uuid=$i;done

Delete 'orphaned' patches and backup patches:

Do not delete /var/patch/applied or its contents.

rm /var/patch/*-*-*-*-*

For true emergencies or for patch install problems, you can delete patch backups:

rm -rf /opt/xensource/patch-backup/*-*-*-*-*

On the Pool Masters, we mount an NFS backup share on /mnt/backup.

Unmount the backup share and delete any 'hidden' files:

umount /mnt/backup && rm -rf /mnt/backup/*
mount -a

Windows Version: http://support.citrix.com/article/CTX129070

Linux Version: http://support.citrix.com/article/CTX129217

This is a procedure to fix XenTools networking issues:

1. Remove network adapter via XenCenter
2. Uninstall XenTools
3. Remove Citrix from filesystem and registry
   • c:\program files\citrix
   • c:\program files (x86)\citrix
   • HKLM\Software\Citrix
4. Run in an admin command shell
   • Stop the running XenTools services
   • sc delete xenlite
   • winmgmt /resetrepository
5. Reboot
6. Install xentools
7. Reboot
8. Add network adapter