Tag: Linux Administration

Short post: Most important command I always forget

December 30th, 2009 · The Fraser · Linux Administration, Systems Administration No comments - Tags: ,

Often times in the heat of a critical server restart the system decides to FSCK a very large filesystem. If I let it take its natural course it could be a day before its back (for 12TB file systems using ext3). So to stop it from fscking follow this procedure.

1) Restart system
2) When it begins FSCKing, it will start running a percentage counter. Crtl-C from this. It will dump you to Repair Filesystem mode
4) Once in repair after entering the root password you will need to edit fstab to comment out the partition. This fails as it is unable to edit the file as its Read-Only.
3) Run the command “mount -o remount /” or to be absolutely sure “mount -n -o remount,rw /”
4) Comment out the partition in /etc/fstab and restart the box.
5) Once the box has recovered uncomment the partition and mount it.
6) Schedule downtime for the box for fscking.

This doesn’t take into consideration the negative affects of running an ext3 filesystem without fsck for that long a period and cheating to get around it. But there are times when things just have to be fixed ASAP, this comes in handy.

ESXi password changing Part #2

December 15th, 2008 · The Fraser · Vmware Administration No comments - Tags: , , ,

After finding all the recommendations online to not work. I was forced to completely rebuild the system. This means since its a Dell PowerEdge 2950 with PERC6/i, I had to delete all RAID Virtual Disks. The reason for this was a glitch I had found when first installing the box some 5 months ago. If you configure a ESXi server on a PERC Controller that has more than 1 Virtual Disk, it will not boot. You have to complete installation using one VDisk then successfully reboot it. Once its up, you have to reboot once more create any other onboard VDisks you need then boot completely. It will automatically detect the new drive and format it with VMFS for you.

All this to say I spent most of my day rebuilding an ESXi Host to recover from a lost password. Since this machine will be folded into our VirtualCenter in the near future, it might behoove me to just reinstall using ESX proper like the other servers. I will do some through testing of the host before had to see if there is anything to gain from using the lighter hypervisor over its far more robust RedHat bound ESX brother.