I've been given a server running Ubuntu 12.04 LTS and I would like to bring it up to at least the next version 14.04 LTS, or preferably the current version 18.04 LTS. The server has ~ 32 TB of data spread out over several Linux volume groups mounted to the filesystem, with /var taking up nearly 10 TB and backups from other servers being kept on /mnt and consuming 22 TB. It's a bare metal server, not a virtual machine, and it's also in production so the upgrade process needs to go smoothly so that our code repository and also our ticketing system remain available with minimal downtime. Removing the backups mounted to the filesystem would trim the overall filesystem down to ~ 10 TB. Most of our applications and the usual system stuff are resident in /var however so I cannot simply unmount it in order to shrink the filesystem any further. The LVGs are carved out of a single RAID 5 array. (I'm aware that RAID 6 or RAID 10 would be preferable but I was recently handed the machine and did not design or build it.)

Ideally, when doing an upgrade to a server, I like to duplicate the environment as closely as possible and test the process in order to make sure that there's no issue with either upgrading the kernel or especially the applications. In this particular case, I don't have TBs of space anywhere to either clone the machine for a VM or have the resources to create a duplicate bare metal server. As 12.04 has now reached EOL, and the server has not had security updates in a long time, it is imperative to upgrade the server as soon as possible to at least 14.04 LTS. I've done *nix upgrades before in my career, but I'm not a Linux specialist, and I don't have any experience with a server this large.

I've googled for the best practices for testing and dist-upgrading a large production server but I'm not getting anything particularly useful. Does anyone have any resources that they could point me to or have any advice for the best way to tackle this beast? Thank you in advance for your assistance.

Hi & Welcome to LQ-

Congrads on getting a server.

I can't walk you through the upgrade but I did find some good links for you to start reading at the very least.

-:::-Best to wait for members here with Ubuntu server experience.-:::-

To cleanly upgrade from 12.04 to 16.04, you must first upgrade the system to 14.04, then to 16.04:
http://robots.mobilerobots.com/wiki/..._16.04_(xenial)

https://www.digitalocean.com/communi...untu-14-04-lts

Ubuntu Server Guide

https://help.ubuntu.com/lts/serverguide/

Good Luck:-

In future it would be better to not respond like this as it stops the thread from being reposted automatically as a zero-reply.

@IT Bard, this sounds like there is no backups of this system - RAID is not a substitute for backups. You may not have designed it, but if it's now your neck on the chopping block, you need to make your line manager(s) aware of the risks.

Is the system itself on a lv ?. Boot doesn't really matter if it's not, so long as the rest is. If so snapshot is a good option, although the roll-back if needed could cause a bit of an outage. For a system update (or worse two) you'll need a bit of space, but nothing like 10T. And it can be easily reclaimed later.

Hi Chaps,

I would strongly recommend you speak to the managers and advise to migrate to a new hardware!
That way you can maybe go for a VMware Suite Solution and gives you more times to install and configure the new environment and migrate the data over slowly.
If you go with VMware Suite you will be able to create snapshots which will allow you to revert back and try again.

Best to leave the current environment in place. The engineer before your time should of done his job by updating the server.

Good luck and let us know how you get on.