alexei alexei@cimedia.com writes:
As I contemplate upgrading all my old filers from 4.x to 5.x, I was wondering what the horror stories are out there. Or is this truly a simple upgrade?
It's a simple upgrade, but here's my cautionary advice:
1. Upgrade one non-critical filer for at least a week prior to upgrading the rest (I actually stagger upgrades even more than that). Some problems can take a while to show up (like backup failures).
2. Don't downgrade. 5.x changes the filehandle format and some releases didn't behave correctly when downgrading from 5.x to 4.x. The result was that every client needed to be rebooted due to stale filehandle problems. I'm told this is fixed these days, but I still wouldn't trust it -- downgrading is undertested. (How many downgrades are there relative to the number of upgrades.)
My horror story is having to reboot 200+ Unix clients because we downgraded two filers from 5.x to 4.x. This was, according to someone at NetApp, a minor problem. If you don't mind rebooting your clients, this is a minor problem, but if you have to explain the rebooting to hundreds of engineers, it's something else.
This is another reason to only upgrade one filer at first.
3. Some options are per-volume. (For example, "options nosnapdir off" is now "vol options vol0 nosnapdir off".)
4. And obviously, read the docs, *upgrade the firmware* if necessary, have some emergency floppies on hand, etc.
I should mention that we are running 5.0.1 and 5.0.2 on all of our filers for some time now, and we are contemplating upgrading to 5.1.2. (The problem that caused us to downgrade from 5.x to 4.x has since been fixed in 5.x.)
Dan