Here's a tip for all readers which is based out of personal experience. We use a lot of virtualization, and we often notice that servers start responding unusually slow to our queries. Once when that happened, we looked at the PLE values, and they had fallen sharply. Later we came to know that our IT started off a whole bunch of guest systems on the same host at the same time causing unexpected memory pressure. Ever since then, whenever our VMs are slow, we look at the PLEs and upon investigating find that some or the other memory-intensive operation is ongoing on the physical host.
Moral of the story - this counter is very, very important in virtualized environments.
Thanks & Regards,
Be Courteous. Drive responsibly.
commented on Jun 21 2011 11:40AM