SDX SVM version 11.1-53.11 has an issue with the /var HDD filling up due to increasingly large log files.  
      Note: There is a valid workaround for 11.1-53.11 or permanently fix it by upgrading to refresh build 11.1-53.13

• HDD /var/ full or increasing
• Unable to login to SVM
• SSL Chips/Cores not detected
• Cannot create a new VPX instance
• VPX instances down or halted
• SVM may not detect RAID information
• AFFECTED BUILD: 11.1-53.11
• NOT AFFECTED: 11.1-52.13 or 11.1-53.13 (refresh build)
• Also fixed in 11.1-54.14

1. Apply workaround shown below. The workaround is a very simple one-time job.
2. Go back to older version 11.1-52.13 or upgrade to the refresh build, 11.1-53.13.

Workaround:

Determining if you’re SDX is affected:

1. Login in dom0 (XenServer)
2. Check the file permissions.
3. Check the free disk space available # df.  If disk space is full and there are large log files under /var/log you MAY be facing this issue.

# ls -l /opt/xensource/bin/rotate_logs_by_size

-r–r–r– 1 root root 3794 Mar 27 13:48 /opt/xensource/bin/rotate_logs_by_size

If file permissions are as above “-r–r–r–” without any “x” then that’s the problem.

Fixing the problem:

1. Backup large file/logs and remove them to free up space on disk.
2. # chmod 555 /opt/xensource/bin/rotate_logs_by_size
3. Change file permission by using following commands:

Recheck file permission:

# ls -l /opt/xensource/bin/rotate_logs_by_size

-r-xr-xr-x 1 root root 3794 Mar 27 13:48 /opt/xensource/bin/rotate_logs_by_size

Reboot the system for the changes to take effect immediately or wait a few hours to be effective.

• https://support.citrix.com/article/CTX223787
• https://support.citrix.com/article/CTX224445