All Wordpress on our VPS is currently experiencing this problem:
Fatal error: Out of memory (allocated 18874368) (tried to allocate 122880 bytes)
I don't know how to fix it. HELP!
Sorry for answering with another question, could you please elaborate on your current configuration?:
+ Kind of VPS (OpenVZ/Virtuozzo, Xen, Linux VServers, KVM, VMWare, VirtualBox....).
+ Size of VPS (RAM, specially RAM), but depending on the VPS kind (previous item), there could be other parameters to look after, this is specially true for OpenVZ.
+ Your current flavor/config of web server.
When you have the info, just post it, please, remember to remove any info you don't want public, maybe: domain name, email addresses, IP addresses, .....
Yes, almost everyone know that's a php message, but if you want to prevent further problems, you need to tune the parameters according to the server you have, for example, you could add:
memory_limit = 256M (for example)
and have apache with mpm prefork, and have a max of 150 childrens, then you could en up requiring up to: yay, 37.5GB! RAM (physical + swap), off course, this is hypothetical, because this is the worst of the cases where the app can actually eat 256M for each request, which is not always true.
Also, you have to fine-tune the DB, so it doesn't eat lots of memory, but all of this parameters will depend on:
+ Size of VPS,
+ Kind of VPS: whether the VPS have or have not swap, depending on the kind of VPS, there can be other parameters to take into account.