Can you set a pagefile more than 4GB?

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Can you set a pagefile more than 4GB?

Stanley Chan

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August 17, 2010 at 9:56 pm

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Comments posted to this topic are about the item Can you set a pagefile more than 4GB?

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David Baffaleuf SSCrazy Points: 2159 More actions · Answer 1

Hi Stanley, thanks to share.

Can you tell us whether your server is 32 or 64 bits ?

David B.

ta.bu.shi.da.yu Hall of Fame Points: 3985 More actions · Answer 2

David BAFFALEUF (8/18/2010)
Hi Stanley, thanks to share.
Can you tell us whether your server is 32 or 64 bits ?
David B.

I know where this is going. If it's a 32-bit machine, it can't address more than 4GB of memory.

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ab.sqlservercentral SSC Journeyman Points: 89 More actions · Answer 3

Hi,

Nice article, but it's worth to mention that it won't work with different paging files spread around different partitions. Unless you have enough free space on c:\ the dumps will be corrupt. We had it a lot of times and did multiple investigations - dumps will be actually cached on first paging file (on drive c: usually) before they will get copied to the other paging files.

So either you make your first paging file large enough, or you won't get a dump that can be fully analyzed.

In case you don't have enough space left, you should rather go for a "kernel memory dump" which fits the needs for analysis in about 98% of all cases. (Actually a bluescreen can happens in the priviledged kernel mode, this the inital stacktrace/trigger will always be visible in the kernel dump, the further analysis however can get stuck at a certain point as user memory is missing)

regards

Andreas

Stanley Chan Mr or Mrs. 500 Points: 560 More actions · Answer 4

David BAFFALEUF (8/18/2010)
Hi Stanley, thanks to share.
Can you tell us whether your server is 32 or 64 bits ?
David B.

They are 32 bits.

Stanley Chan Mr or Mrs. 500 Points: 560 More actions · Answer 5

ta.bu.shi.da.yu (8/18/2010)
David BAFFALEUF (8/18/2010)
Hi Stanley, thanks to share.
Can you tell us whether your server is 32 or 64 bits ?
David B.
I know where this is going. If it's a 32-bit machine, it can't address more than 4GB of memory.

Hi David,

With Windows Server 2003 Enterpise Edition, and PAE switch in boot.ini, it can address more than 4GB memory.

David Baffaleuf SSCrazy Points: 2159 More actions · Answer 6

Hi,

Thanks for your answers. I know PAE allows windows to go beyond the 4Gb boundary. I was rather interested because in the referenced KB article, it is said :

"The Complete memory dump option is not available on computers that are running a 32-bit operating system and that have 2 gigabytes (GB) or more of RAM. (...) "

David B.

alen teplitsky SSC-Dedicated Points: 30014 More actions · Answer 7

Stanley Chan (8/18/2010)
ta.bu.shi.da.yu (8/18/2010)
David BAFFALEUF (8/18/2010)
Hi Stanley, thanks to share.
Can you tell us whether your server is 32 or 64 bits ?
David B.
I know where this is going. If it's a 32-bit machine, it can't address more than 4GB of memory.
Hi David,
With Windows Server 2003 Enterpise Edition, and PAE switch in boot.ini, it can address more than 4GB memory.

there are a lot of limitations in how it addresses the RAM above 4GB. this is why we are replacing all 32bit servers with x64 ones

SanjayAttray SSChampion Points: 13157 More actions · Answer 8

I had to change it to 6 GB from default size of 2 GB on a production server few days back. Also, by default pagefile.sys is located in C:\ drive and now changed to D:\ as C:\ generally had a low on space than compared to other drives.

another bad while changing the size or path to this file is that you have to reboot server to take it effected and would recommend all to do in a maintenance window period.

I have to change the size and path on a clustered environment and had to figure it how ? As this file should be on local drives only. Had any body had made changes on Clustered A\P environment ? Kindly post how.

Thanks.

SQL DBA.

Stanley Chan Mr or Mrs. 500 Points: 560 More actions · Answer 9

ab.sqlservercentral (8/18/2010)
Hi,
Nice article, but it's worth to mention that it won't work with different paging files spread around different partitions. Unless you have enough free space on c:\ the dumps will be corrupt. We had it a lot of times and did multiple investigations - dumps will be actually cached on first paging file (on drive c: usually) before they will get copied to the other paging files.
So either you make your first paging file large enough, or you won't get a dump that can be fully analyzed.
In case you don't have enough space left, you should rather go for a "kernel memory dump" which fits the needs for analysis in about 98% of all cases. (Actually a bluescreen can happens in the priviledged kernel mode, this the inital stacktrace/trigger will always be visible in the kernel dump, the further analysis however can get stuck at a certain point as user memory is missing)
regards
Andreas

Andreas,

Thanks for your comments. Yes, it requires a single page file in C: which is big enough. For those servers with more than 64GB memory, it is not common to have a large enough C:.

Stanley Chan Mr or Mrs. 500 Points: 560 More actions · Answer 10

SanjayAttray (8/18/2010)
I had to change it to 6 GB from default size of 2 GB on a production server few days back. Also, by default pagefile.sys is located in C:\ drive and now changed to D:\ as C:\ generally had a low on space than compared to other drives.
another bad while changing the size or path to this file is that you have to reboot server to take it effected and would recommend all to do in a maintenance window period.
I have to change the size and path on a clustered environment and had to figure it how ? As this file should be on local drives only. Had any body had made changes on Clustered A\P environment ? Kindly post how.
Thanks.

Sanjay,

It doesn't matter how the pagefile defined in Clustered environment.

e.g. Node A has a 2GB pagefile in C: only, node B has a 4GB pagefile in D: only.

If the cluster group hosts on node A, the cluster has 2GB pagefile in C: (that's what Node A configured). If the cluster group failover to node B, the cluster has 4GB pagefile in D: only (that's what Node B configured).

Nitya Say Hey Kid Points: 699 More actions · Answer 11

We have twice as much of Memory allocated as pagefile.

Is there a threshold or related impact on having such a setup?

James Stephens Mr or Mrs. 500 Points: 517 More actions · Answer 12

This is good information to know. I hate to get negative on MS but I have to:

Why should a professional server administrator need to resort to "tricks" and "hacks" to do something--not only normal--but *required* if one wants to actually support a mission-critical machine? Why couldn't one just set the pagefile size--or--better yet--have it default to the minimum required?

My questions are rhetoric, this is just a head-shaker.

---Jim

YeshuaAgapao Hall of Fame Points: 3495 More actions · Answer 13

I use the /PAE boot.ini switch on a 32-bit windows XP workstation with 4GB of RAM. It not only lets me use 3.25GB of that RAM, it lets me set the paging file to whatever size I want (I set to 8GB initial 16GB max)

SanjayAttray SSChampion Points: 13157 More actions · Answer 14

Stanley Chan
Sanjay,
It doesn't matter how the pagefile defined in Clustered environment.
e.g. Node A has a 2GB pagefile in C: only, node B has a 4GB pagefile in D: only.
If the cluster group hosts on node A, the cluster has 2GB pagefile in C: (that's what Node A configured). If the cluster group failover to node B, the cluster has 4GB pagefile in D: only (that's what Node B configured).

Thanks for explanation, Stanley .

SQL DBA.