[UPDATE] This also applies to 3.2. I’m finding that I have to deactivate more and more plugins as time goes on. I believe it is the UNZIP operation that is eating up so much memory. But something awesome should occur after you get 3.2 installed…future upgrades are only going to update the changed files. This means that the zip file should be a lot smaller. In fact, I was able to update to 3.2.1 without deactivating plugins (NOT RECOMMENDED…but I do it anyway).
I tried upgrading my WordPress sites to WP 3.1.1 tonight, but got the following message on each one: Fatal error: Allowed memory size of 31###### bytes exhausted (tried to allocate 29##### bytes) in /home/???/????/wp-includes/class-http.php on line 1426
The quick and simple fix
A quick thing to try is to deactivate a couple of big plugins.
On one site, I deactivated PhotoSmash and it installed fine. Fearing that PhotoSmash was causing the problem, I tried deactivating NextGEN Gallery on my development site, and left PhotoSmash running, and it installed ok then too. Whew! It’s not PhotoSmash!
In case you’re wondering, I develop PhotoSmash, but also run NextGEN on my development site so I can stay compatible with the big kahuna ;-).
Memory Allocation on my Shared Host
The weird thing is that my shared host (1and1) allocates 250MB of memory — see screenshot to the right –, so theoretically (I think), the upgrade shouldn’t have pooped out until it hit that limit. UPDATE: I learned that even though the server settings at the right shows I have a 256MB memory limit, that this is not true. WordPress itself tries to set a higher memory limit, hence the indicator of 256M. In reality, I’m limited to the 32MB allocated by my Web Host. I keep encountering the error at around 31MB.