I have a lot of virtual servers that are configured with 16gb ram.
By default windows will create a 16gb pagefile (auto manage page file size)
What would you guys say is a good pagefile size for win 2008 r2 servers running on ESX 5 ? (My servers consume around 70% of dedicated ram)
Is it bad to "lock" the pagefile to 2gb?
I'd say there is not much special concerning size of pagefile for Win2008 running on ESXi, or running Win2008 on "plain" hardware. The same rules as for standard Win2k8 installation applies here. The "good" size is the one you need...
I'm running a few windows servers with no pagefile at all. Some say it is a bad idea, but it works for me, because I try to have so much ram (which is quite cheap these days) that my servers never touch swap/pagefile. There was (and maybe still is?) some app-software which refuses to start if there is no pagefile at all, but I do not have it. Moreover, I do not see a reason why some application should "talk" to memory management, it is a task for OS: if app needs "X" GB, it put request on it, and it is up to OS to deal with it (either as full ram commitment, or partially in pagefile)...
One more reason I do not use pagefile (in addition to "I do not need it") is that "I'm affraid of security implications". If pagefile is not cleaned/removed at shutdown (which takes some time), or encrypted (which takes cpu-cycles), there might be sensitive data saved there (i.e. passwords, pins, etc), sometimes even as plaintext, which are not difficult to recover...
You would do exactly what you would do if the server were physical. Meaning, the answer is "it depends"
Thanks for your answers.
I don't agree with : "You would do exactly what you would do if the server were physical. "
Because with hyper-visors u often have shared storage and you can save alot of diskspace. (Today i have over 100 web servers that each have a 16gb pagefile)
On a physical server you usually dont bother about the diskspace....because the storage is less expensive and you have plenty.
Gonna do some testing like JarryG says, i dont see why my native win 2008 r2 server with IIS would need a pagefile.
This is where the depends come in - if you have sufficient memory in your ESXi host so that the pagefile is not overly taxed when there is contention for memory
I guess I should say "ideally" you would do what you would do if the server were physical. Ideally, you're going to have shared storage with thin provisioning and/or dedupe enabled, and/or thin provisioned VMDKs. Applications like SQL Server are going to claim space in the page file, but Windows isn't typically going to write the full 16GB to the page file unless it actually needs to be paging out for some reason. It would be ideal for to allow Windows to manage its own internal paging, but was we said, "it depends".
I can't think of a great reason to disable the page file, and if you do it, balooning is not going to work the way you would expect.
ok, thanks for your replies.
But if you have win 2008 r2 web servers with 16gb ram like me.
How would you then config the pagefile? Size the the file to 4gb? (Servers will never be out of RAM)
Here's a nice article from Mark Russinovich (the guy behind Sysinternals) Pushing the Limits of Windows: Virtual Memory - Mark&#39;s Blog - Site Home - TechNet Blogs
He gives some information as well as how to determine how big it should be. Also he wrote why it's not so bad to have it (dumps). Seems old but he covers 2008 as well as 64 bit so I would say it's still valid and gives some nice infos.
My conclusion: You can use the defaults or you have to do some work and really have to measure how big/small the paging file has to be. If you have a lot of 2008 R2 webservers it might be a good idea to measure how much is used because of shared storage prices.
You might create a second vmdk for your VM(s), make it thin, reconfigure the pagefile inside Windows to that new disk/partition. If you have 16 GB of vRAM on the VM then 4 GB should be fine.
You might (is possible) locate all VMs pagefile disks on another datastore, which could be a thin provisioned LUN from the SAN side and/or backed up by less expensive disks. If you are quite sure the internal Windows pagefile will be used very little then some slower disk could be very acceptable.