However, ESXi 5 moved the goalposts, with USB or SD storage no longer suitable for persistent storage: hosts without local storage now mount a 32Mb Ram Disk to mount the scratch partition to.After upgrading to ESXi 5 we saw several instances of host instability as the Ramdisk ram out of space, symptoms including :- The VMs themselves continued to run on the host, just not able to manage the host properly.To check the amount of memory available, type the command MEM at the DOS prompt.
As a short term fix to bring the server under control again – providing the Shell is enabled – we logged onto the shell, navigated to the /var/log folder and deleted any archived log files (ending .gz) and created a new, empty wtmp file (the file recording shell access).
That recovered enough Ramdisk space for the server to become manageable again.
The easiest place to find this number is on the Keystroke logo screen.
IMPORTANT: If you are experiencing random errors with your system, please review the section on Power Conditioning at the beginning of the Custom Modules and Advanced Features User Guide Appendix.
We deployed a single 50Gb LUN called “Logs” just for the purpose of storing log data for our 5 hosts, then changed the Advanced Settings parameter Scratch Config.