Tuesday, March 27, 2012

Do I still need pagefile?

Hi,
If I have 16GB RAM on my 4 CPU box for my SQL Server, do I still need
pagefile?
Thanks!
JohnAbsolutely, you must have a page file...
Wayne Snyder, MCDBA, SQL Server MVP
Mariner, Charlotte, NC
www.mariner-usa.com
(Please respond only to the newsgroups.)
I support the Professional Association of SQL Server (PASS) and it's
community of SQL Server professionals.
www.sqlpass.org
"John Lee" <johnl@.newsgroup.nospam> wrote in message
news:OOfwjpOZFHA.580@.TK2MSFTNGP15.phx.gbl...
> Hi,
> If I have 16GB RAM on my 4 CPU box for my SQL Server, do I still need
> pagefile?
> Thanks!
> John
>|||Yes. Wayne is correct a page file is required. However, (assuming a 32 bit
version) you will be using PAE and AWE. With AWE the memory SQL Server will
all of the memory you defined to it apon startup and will not exceed that
amount. The only use of the page file should be any other applications
running on the server. You also need to have a page file big enough for
whatever kind of memory dump you need in case of a blue screen.
Danny
"John Lee" <johnl@.newsgroup.nospam> wrote in message
news:OOfwjpOZFHA.580@.TK2MSFTNGP15.phx.gbl...
> Hi,
> If I have 16GB RAM on my 4 CPU box for my SQL Server, do I still need
> pagefile?
> Thanks!
> John
>|||Wrong answer. Again, assuming this is a 32-bit platform, you can only store
data pages in the AWE mapped memory space, and, perhaps a few other trivial
items. Data pages, however, will be the bulk of that usage. That means all
of the other 4 memory managers, the active data pages, and the MEM TO LEAVE
area will all reside in the lower 2 GB of physical ram.
2 GB? Yes, if you have 16 GB or more, you MUST NOT USE the /3GB switch and
if you are on Win2K3, then you also want to use the /USERVA to scale the 3
GB back incrementaly from 3 GB to 2 GB starting around the 12 GB mark.
Now, what happens when you have cached procedures and new compile requests
come in? Most likely, you will flush old execution plans. Correct. Now,
what if the bulk of them are currently active? That's right, the free list
drops and eventually even SQL Server will start paging to the swap file;
that is, if it exists...right?
If you are needing the 16 GB of ram, seriously consider migrating to the
64-bit platform, the IA64 of course, where all the memory managers have use
of the entire memory segment.
Sincerely,
Anthony Thomas
"Danny" <someone@.nowhere.com> wrote in message
news:CcFme.6751$m%3.4525@.trnddc02...
Yes. Wayne is correct a page file is required. However, (assuming a 32 bit
version) you will be using PAE and AWE. With AWE the memory SQL Server will
all of the memory you defined to it apon startup and will not exceed that
amount. The only use of the page file should be any other applications
running on the server. You also need to have a page file big enough for
whatever kind of memory dump you need in case of a blue screen.
Danny
"John Lee" <johnl@.newsgroup.nospam> wrote in message
news:OOfwjpOZFHA.580@.TK2MSFTNGP15.phx.gbl...
> Hi,
> If I have 16GB RAM on my 4 CPU box for my SQL Server, do I still need
> pagefile?
> Thanks!
> John
>

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