Hello all.
My company is installing an SAP ERP financials. The consultants are asking me to allocate 30Gbytes of swap. This is on a dedicated Linux box running Redhat 5 64Bit OS. It has 16GB of RAM.I have asked for an explanation but all I'm getting is that this is what SAP recommends. It seems really strange. Redhat recommends 1/3 times RAM for swap on RHEL5. I am seeing virtually no swapping going on. It seems to me if they need this much swap I should be adding RAM. My experience from way back it that too much swap on a linux box can cause problems. This was back in 2002 or so but I'm sure we were seeing really bad performance with too much swap that went away once we reduced it to 2GB of swap only.
My question is simple. Anyone out there running SAP with less swap than RAM? If so, are you experiencing and real problems?
Thanks.
I never heard of SAP or ERP. In general, with 16 GB of RAM, I would go with 8GB of swap. 30 GB of swap seems very excessive; however, it should only waste disk space that might be better used elsewhere. I have never seen a performance hit from "too much" swap. That sounds like a bug.
jhtrice,
Your consultant is following the SWAP = (Physical Memory * 2) type of implementation. You can set 8 GB of swap and add another swap if your system really needs it.