Can you set a pagefile more than 4GB?

  • Stanley Chan

    Mr or Mrs. 500

    Points: 560

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

  • David Baffaleuf

    SSCrazy

    Points: 2159

    Hi Stanley, thanks to share.

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

    David B.

    David B.

  • ta.bu.shi.da.yu

    Hall of Fame

    Points: 3985

    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.

    Random Technical Stuff[/url]

  • ab.sqlservercentral

    SSC Journeyman

    Points: 89

    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

    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

    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

    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.

    David B.

  • alen teplitsky

    SSC-Dedicated

    Points: 30014

    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

    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

    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

    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

    We have twice as much of Memory allocated as pagefile.

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

  • James Stephens

    SSC-Addicted

    Points: 497

    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

    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

    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.

Viewing 15 posts - 1 through 15 (of 37 total)

You must be logged in to reply to this topic. Login to reply