Random system freeze, Ubuntu LTS on VMWare Server 2.02
I have a very simple LAMP Ubuntu LTS webserver, running "CMS Made Simple" on VMWare Server 2.02 (free edition) for the past four years or so.
It's been stable for years and years, but occasionally crashed due to running out of disk space due to logs overflowing and backups accumulating.
Lately however the system has become increasingly unstable and will occasionally randomly completely lock up and the GUI goes unresponsive.
For a while the Update Manager has been saying an upgrade to a new LTS release is available, so I copied the virtual machine drive to retain the old system, then did the upgrade. All through the process it would say, "changed config file found, keep old config?" and every time I'd say no, since the differences were not made by me.
So it appears the system is fully up to date, with all the global config files of the new LTS version, plus my CMSMS and it works properly .,.... but still freezes solid occasionally.
This last week it has frozen up literally every other day. Not good when there are staff that depend on it being available.
It seemed like this could be a GUI graphics driver problem, so I set up alternative access. It did not help. I haven't ever seen a need for SSH, but installed it last week and left the system logged on through PuTTY to the shell prompt. When the system froze, both the GUI and the SSH prompt were unresponsive.
I hate hard-resetting a system running a MySQL database since it risks database corruption, but I have no other choice apparently.
I am contemplating building a brand new "clean install" Ubuntu LTS virtual machine and reinstalling CMSMS and the MySQL database on it, though before I do that, I should ask if there are any known problems with LTS and VMWare Server 2.02.
Re: Random system freeze, Ubuntu LTS on VMWare Server 2.02
I'm not an expert on anything Linux or VMware Server, but I have been running Ubuntu Server 10.04 LTS and 12.04 LTS as well as performing in-place upgrades and out-right re-building a new 12.04 server in order to migrate data/services from a 10.04 server. All of this experience has been while using it inside a VM running VMware's ESXi server 4.1.
I have not found any stability issues with the server except when I was initially trying it out inside Oracle's VirtualBox. I'm not sure if it was Virtualbox or Ubuntu or a combination of both but it was utterly miserable trying to setup a 10.04 server to run Zimbra last year...that is until I installed Ubuntu on ESXi and at that point, the stability problems went away completely. No more utterly random and insanity-induced glitches.
I have dedicated servers running Nagios, MySQL, Apache/MediaWiki, Apache/phpBB, Zimbra, MineCraft/CraftBukkit, Zentyal CUPS printer and all of them running Samba for file-sharing across different platforms.
So, with that all said, my 1st recommendation would be to copy your VM to a different PC and see if it will run in a stable manner on a different box to rule out hardware issues such as bad ram/hd/psu/etc.
Once the problem is isolated to just inside the VM, the next thing I would do would be to re-build a new VM and see if you can make a similar stable platform using the exact same versions of software you are running in your original VM. If it remains stable, try migrating your data to the new VM and see if it continues to be stable. If so, simply start using the new VM as your primary service.
Once stable on the current system, you can then start looking at creating a new VM with updated software if you want to go that route (or simply duplicate the system and see if an in-place upgrade will actually work).
I prefer making new VMs from scratch when a new release comes out and migrate data rather than trying to migrate in-place. Too many variables can be introduced during an upgrade (as you have seen) and the more complex your system, the more complex the upgrade can be. A migration of my MySQL database could not have been more simple going from a 10.04 server to 12.04...check my sig for the thread and look at the migration steps I did to transfer the database and make it live. EASY!
When troubleshooting, always try to isolate potential problems to rule them out or prove the case.
Last edited by LHammonds; May 23rd, 2012 at 04:01 AM.
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