Upgrade 1500 servers in 6 months
By John Clingan on Jan 11, 2005
I just read Chris Gerhard's blog entry on installing Solaris on a Toshiba Tecra M2. Many at Sun have this laptop as it was one of the standard laptop upgrade options the last go-around, myself included.
Chris gives an excellent tip that many Sun employees use when installing Solaris these days, and that is to leverage Live Upgrade when installing Solaris 10 (or 9, or 8). Disk drives are so large today that saving some extra space for a copy of a partition (or two, or three) isn't all that big a deal. Chris's point of upgrading your OS while you are doing productive work is a top-notch point. You are only down for the length of a reboot. Have a problem with your upgrade? Boot the unmodified image you upgraded from.
What most folks do is reserve enough space for two images, but you can have more. Another good tip for this is development, and this came up yesterday at a customer. You can keep the old environment around and boot to it for regression testing.
There is a lot of information at Sun.com on Live upgrade, including using it for rapid upgrades and patch management. Check out the big admin articles and search in page for "live upgrade". The Sun Blue Prints also have a lot of good info on Live Upgrade. Search in page for "Live Upgrade" there as well.
To prove the usefulness of Live Upgrade, it was integral to our upgrade of our 1500 servers in just 6 months. No were not talking 1500 servers in a web farm that look exactly alike. Check out the white paper that explains how we did it. IMHO, this is required reading for any admin that will upgrade Solaris (yeah, that means every sysadmin).
Update: Forgot to mention that I used Live Upgrade to remotely upgrade my personal server from Solaris 8 to Solaris 9 a couple of years back. Only issue I had was two ssh daemons fighting for the same port (Solaris 9 includes ssh, which confliced with my manually-installed Solaris 8 ssh daemon). Hey, I'll take that level of debugging any day for a remote server upgrade with downtime of 3 minutes.