pagefile necessary?

Hi

I wasn't sure where to post this question, so decided to post it in this
section.

I am running W2k8 x64 on a server with 16GB RAM and virtual memory is
initially set as 'System managed', which causes a pagefile of 16.3GB to be
created.

As the server is short on disk space and could use this 16.3GB very nicely,
my question is:
Assuming server load never exceeds the amount of RAM available, is the
pagefile necessary?

Would it be better to disable the pagefile completely, or to use a custom
size like 800MB(Min) to 2048MB (Max) ?

I have scoured the Internet for information, but so far am still undecided.

Any advice would be greatly appreciated. Thanks in advance.

> Assuming server load never exceeds the amount of RAM available, is the
> pagefile necessary?

under this assumption it is not necessary.

But using a swap file gives the system the chance to swap out unneeded pages
(sleeping processes and stuff). When another application suddenly needs the
memory it will have the chance to get it. Without swap it would be out of
luck.

How much swap depends on your usecase. For me on a desktop system where most
applications are in use by me, 2 GB is more then enough. I won't have the
patience to wait for applications to swap in for 2048 MB / 80MB/sec disk
speed = half a minute. But maybe on a server where many hundred processes
idle most of the time and are not that big to swap in, it might be ok to
have a huge swap.

Andreas

In article <BBB6713E-506A-4F9B-93C0->,
=?Utf-8?B?YmluZ3llbw==?= <> wrote:
>Hi
>
>I wasn't sure where to post this question, so decided to post it in this
>section.
>
>I am running W2k8 x64 on a server with 16GB RAM and virtual memory is
>initially set as 'System managed', which causes a pagefile of 16.3GB to be
>created.
>
>As the server is short on disk space and could use this 16.3GB very nicely,
>my question is:
>Assuming server load never exceeds the amount of RAM available, is the
>pagefile necessary?
>
>Would it be better to disable the pagefile completely, or to use a custom
>size like 800MB(Min) to 2048MB (Max) ?

Only you, your system and your workload can answer your
question. Perfmon is the tool that tells you what your system is doing.

Low disk free space can cause performance problems that might result
in more paging. Shrinking the pagefile is a small and temporary fix
for your real problem.

If it was mine and I could, I'd add a small disk to the machine and
move pagefile to it. That frees all the 16GB and is a performance plus
in general.

On a different tack, I've used NTFS file system compression many
times, even on production servers to make better use of disk space AND
improve server application performance. If you have lots of
non-database data files, I'd try compression on a copy of your data to
see what it buys you.

I've seen compression of 90% on multi-GB folders of numeric data.

When C drives were smaller and our development software was large in
comparison, I used to compress the entire C drive file system on new
atarwma right from the start.

I never tried to compress an Oracle database but I bet it would work
but performance might suck.

--
Al Dykes
News is something someone wants to suppress, everything else is advertising.
- Lord Northcliffe, publisher of the Daily Mail

bingyeo <> wrote:

> I am running W2k8 x64 on a server with 16GB RAM and virtual memory
> is initially set as 'System managed', which causes a pagefile of
> 16.3GB to be created.
>
> As the server is short on disk space and could use this 16.3GB
> very nicely, my question is:
> Assuming server load never exceeds the amount of RAM available, is
> the pagefile necessary?
>
> Would it be better to disable the pagefile completely, or to use a
> custom size like 800MB(Min) to 2048MB (Max) ?

I'd consider using a pagefile of 1/2 ram or 8GB in your case. This is
a rough guess for systems with more than 4G of RAM, see if it works.

NOTE: Set minimum and maximum size to be equal, does several good
things, others may offer a detailed explanation, I'm going back to bed!

--
XS11E, Killing all posts from Google Groups
The Usenet Improvement Project:
http://twovoyagers.com/improve-usenet.org/

"bingyeo" <> wrote in message
news:BBB6713E-506A-4F9B-93C0-...
> Hi
>
> I wasn't sure where to post this question, so decided to post it in this
> section.
>
> I am running W2k8 x64 on a server with 16GB RAM and virtual memory is
> initially set as 'System managed', which causes a pagefile of 16.3GB to be
> created.
>
> As the server is short on disk space and could use this 16.3GB very
> nicely,
> my question is:
> Assuming server load never exceeds the amount of RAM available, is the
> pagefile necessary?
>
> Would it be better to disable the pagefile completely, or to use a custom
> size like 800MB(Min) to 2048MB (Max) ?
>
> I have scoured the Internet for information, but so far am still
> undecided.
>
> Any advice would be greatly appreciated. Thanks in advance.
>

I would add another hard disk just for the swap file. Most of us have an
old small disk lying around and putting the swap file on a separate physical
disk should improve performance as well.

Hi All

thanks for all the replies!

Firstly, unfortunately the said server is a blade server with only 2 disk
slots and it is running RAID 1, so adding of additional disks is out of
question.

So my only options are to either disable pagefile, or configure a custom
sized page file.
Judging from the replies so far, I think I will go with a smaller page file.

My questions on custom page file are:

1. How is using a fixed size pagefile (min size = max size) better than
starting low, and letting it grow as needed?

2. I have logical drives C: and D: on the same physical disk; is there any
difference in putting the page file on C: or D: when configuring the custom
page file?

Cheers

On 07/09/2010 in message
<3BA24B34-0032-4D40-B2D8-> bingyeo wrote:

>My questions on custom page file are:
>
>1. How is using a fixed size pagefile (min size = max size) better than
>starting low, and letting it grow as needed?

A fixed size avoids fragmentation.

--
Jeff Gaines Dorset UK
Tell me what you need, and I'll tell you how to get along without it.

In article <>,
Jeff Gaines <> wrote:
>On 07/09/2010 in message
><3BA24B34-0032-4D40-B2D8-> bingyeo wrote:
>
>>My questions on custom page file are:
>>
>>1. How is using a fixed size pagefile (min size = max size) better than
>>starting low, and letting it grow as needed?
>
>A fixed size avoids fragmentation.
>

Correct but once you've set the settings, you need a stand-alone
defrag tool:

http://technet.microsoft.com/en-us/s.../bb897426.aspx

The link is XP vintage. Has Sysinternals defrag been updated?
--
Al Dykes
News is something someone wants to suppress, everything else is advertising.
- Lord Northcliffe, publisher of the Daily Mail

Hi Jeff

thanks for clarifying.
How about my other question regarding the location of the page file?

Cheers

On 08/09/2010 in message
<E0C9A5A0-E053-466C-99FE-> bingyeo wrote:

>Hi Jeff
>
>thanks for clarifying.
>How about my other question regarding the location of the page file?
>
>Cheers

That's a bit more complex and you have limited options.
I have a separate partition at the front of my least used drive - Backup2
- which is only used when running overnight backups, or in the event of a
terrible disaster!
Since your C and D drives are on the same partition I'm not sure it will
make much difference. If you have a second physical less used drive that
may be better.

--
Jeff Gaines Dorset UK
This is as bad as it can get, but don't bet on it