Thursday, 8 January 2015

XenServer 6.2 update woes

Recently I was required to update a number of XenServers that I've taken over. They were running 6.2SP1 but were about 6 updates behind. No problem, I'll just queue the updates up and shoot them over. Had 2 Windows VM's (2008R2 and 2012 server) and 5 Ubuntu 12.04LTS Linux Servers. The updates were fairly straight forward - I followed my own guide :-)

After the final update was completed I booted up the VMs only to find the two Windows Servers came up no problems, and none of the Linux servers booted. None of them. They started up, black screen and white cursor in the top left hand corner and that was it. No boot no errors, just gone.

I ran through some basic repair work and had no joy. I changed the GrubConf.py from if arg.strip() == "${saved_entry}": to if arg.strip() == "${saved_entry}" or arg.strip() == "${next_entry}":. Still no luck. I re-installed Grub - no joy. I booted from the Ubuntu server CD and tried to run rescue the broken install. On several of the VM's I couldn't even get the system to run a shell in the / file system (/dev/xvda1 typically on these setups). It was incredibly frustrating and after three weeks of banging my head against this, I've still not managed to get this all going.

Luckily I had backups of most of the servers and so I haven't lost everything but I have lost some critical data. The message here, dear friends, is multiple:

  • test the updates one at a time to make sure everything starts up. Yes it will take longer and it's a bit more frustrating, but believe me, you want to know if things are going to shit themselves.
  • backups backups backups - are not important. RESTORES! are the important part. Believe me, I cried into my beer when I couldn't get one of these machines back up and going - it just wasn't going to happen. I lost a wiki with data that wasn't anywhere else and that's caused me no end of grief. The extra work it's caused is phenomenal and I feel very bad about it indeed.
I've reached out to the collective wisdom of SAGE-AU (www.sage-au.org.au) but sadly no luck yet. I'm open to suggestions!

elementary OS Review

I came across elementary OS on LifeHacker I think and thought it looked pretty interesting. I've been looking for a lightweight operating system that's reliable and fairly full featured (I accept it won't be totally featured - that's the cost of lightweight) for use on various older laptops and the like.

elementary OS is a free download with donations as optional. I downloaded it and burned it to a CD. Alas my favourite test laptop has gone the way of the dodo and is never to return (much like the dodo). I found a HP Pavilion D6 floating around, replaced the hard disk (it was toast) and the RAM (also toast) with 6GB. It's an i3 which doesn't really qualify as a lower end machine, but what the hey.

elementary is based on Ubuntu linux and is quite heavily customised running a lightweight desktop called Pantheon. The current version of elementary is called Luna and it's nice to see they are in development of new versions and it seems like an active development environment. Midori is available for Internet access - I installed Chromium as that's my preferred web browser. There is a calendar app, Geary Mail (which I haven't used), Shotwell for photo organisation and Empathy to tie in with Jabber, Facebook etc.

The interface is slick and looks good and the laptop boots a rocket. All the apps are fast and updates etc are easy as pie. There is an application for updates which is simple and straightforward and the whole thing is well organised and designed. It's quite a joy to use actually. The application install package - Software Center - looks good and is straightforward to use, offering a large range of packages. All the stuff I like to use I was able to install and get on with the job. I have a pretty small requirement list though, in the interests of full disclosure. Chromium has to work, I have to be able to burn CDs and DVD's and I need terminal to be fully functional. Pretty, fast and stable are the other three musts for any OS and I find elementary to check all those boxed.

I now run Mint and elementary side by side on laptops and desktops - the speed difference is quite noticeably between the two, and with their ultra stable Ubuntu (Debian) ancestry it's lovely to use. I've enjoyed using elementary OS Luna and I'll be keeping it on my Pavilion for the future - well as long as the Pavilion holds together!