My server is currently running: CentOS 5.2 32bit + Virtualmin Pro. I would like to clean the drives and reinstall CentOS 5.2 with the 64bit version. I wanted to see if anyone has ever done this or can guide me to a post of someone who has. Why switch? I have 12gb of memory on my server - I didn’t know about the mysql 4gb memory limit when installing CentOS 32bit.
One concern I have is doing the upgrade in a timely manner. Is 4 hours reasonable? Curious to know how much downtime to anticipate.
This should be pretty boring (boring is a good thing when you’re talking about backups and restores). But, things can always go wrong.
I would recommend a test run on whatever spare hardware you happen to have (maybe a Xen or qemu or VMWare 64 bit virtual instance on your desktop machine), just to make sure nothing goes horribly wrong and nothing vitally important ends up missing.
We did just learn that stored procedures don’t get backed up in a normal MySQL dump (which is absolutely nuts)…so if you have stored procedures you’ll want to wait until 3.69. Almost nobody uses stored procedures anymore, and it’s taken years for someone to report the problem. But, I thought it worth mentioning, since it certainly shocked us.
I also like to have a full system backup (a tar backup, excluding stuff like /dev, /tmp, and /proc, is most convenient) handy when I do a migration. Knowing that I can untar anything that I forgot about, or whatever, is very relaxing.
So, 4 hours. I dunno. Probably. But, I usually start at about 6PM on a Sunday night, and plan to pull an all-nighter. When it is finished by 9PM, I’m pleased that I get to go home “early”. When something goes wrong, as it occasionally does, I’m not disappointed or unpleasantly surprising. I just have a nice cup of tea and then get back to work. Before founding Virtualmin, I worked as a system administrator for many years. I have a zen-like approach, and never let myself get stressed. Known-good backups make for a happy and stress-free life.
The backups I would be restoring are the virtulamin backups from virtual-server/restore_form.cgi
I would no doubt backup the /home account and mysql databases. Thanks for the info about the "stored procedures"…
Unfortunately where the server sits, they don’t allow me to come in after 5pm. I too would rather come in late knowing I have close to 10 hours to work on it, if needed. But that isn’t the case…
I believe I would need to reformat the drives since a raid array is in place? If so, that alone would take more than a few hours, there are 4 drives + 1 hotswap.
Ok, well I just wanted to make sure there was no Virtualmin 64bit or something. It seems the same install script is being used for both 32 and 64bit installs.
I will update you on my "how long does it take" findings
You don’t necessarily have to reformat. The RAID format and ext3 filesystem format is the same across 32 and 64 bit systems.
You could, theoretically keep /home and backup /var and /etc, and then pull them back in. But, I think you’re probably best off starting from scratch (along with known-good backups of the virtual servers made with Virtualmin and known-good full backups of all filesystems using the Webmin Filesystem Backup module, or some other full-featured backup utility). You won’t have to think as hard about what sticks around and what goes.
And, repartitioning and creating new filesystems is the fastest way to erase everything on the disks to start from zero.
All of our software (except procmail-wrapper) is in Perl (or Java or JavaScript or shell). It is the same on all platforms.
All of the ancillary stuff, however, is very specific. Our Apache build, and anything else in the /centos/5/$arch/ repository is definitely going to need to be the right version for your architecture. There’s a repo for i386 and one for x86_64.
