1 2 3 Previous Next 31 Replies Latest reply on Aug 13, 2006 7:34 PM by mstahl75

    How big to make the SWAP Partition

    dwchan Expert

      With ESX 3.0, does it following the same rule and guideline when it come to SWAP partition size?  If I have a 16G ESX host, do i setup a 16G SWAP Partition during the setup?

       

      dwc

        • 1. Re: How big to make the SWAP Partition
          mstahl75 Master

          The recommended SWAP is 544 MB which is 2x the COS memory.

          • 2. Re: How big to make the SWAP Partition
            dwchan Expert

            Even if I physically have 16G or more of memory?    What is I have like 12 VM guest?  Is this the same SWAP file for the VM that you use to configure within the web interface?

            • 3. Re: How big to make the SWAP Partition
              Michelle Laverick Virtuoso

              COS swap has nothing to do with virtual machine the memory they use (16BG - the COS allocation)

               

              The max amount memory for the COS is 800 - and can be adjusted. Some community member create a full-allocated swap partition of double this value which is 1.6GB...

               

              Each virtual machine now gets own "personal" swap file based on the max amount of memory you assign to it... it has vswp extension and will be in the dir where your VMX file is... VMware no longer use a per HOST vmkernel swap file but a per VM swap file... this is for such features as memory over-commitment...

               

              Regards

              Mike

              • 4. Re: How big to make the SWAP Partition
                mstahl75 Master

                In ESX 3.0 the amounts of memory for the COS is set to 272 MB. From some postings here it has been stated that there is no need to increase that amount. Alot of the things that were handled by the COS before are now handled by the kernel itself which will use as much memory as it needs to provide those services. I'll look for a link for the post that discussed this and try to give one.

                 

                The installation documentation give 544 MB for the swap space for the COS and doesn't suggest that it needs any more than that.

                • 5. Re: How big to make the SWAP Partition
                  mstahl75 Master

                  url=http://www.vmware.com/community/thread.jspa?threadID=48409&start=20&tstart=0This topic[/url], in particular the second post on the third page (linked to that page), discusses the issue more. Also, the one after I asked about increasing goes into it some more.

                  • 6. Re: How big to make the SWAP Partition
                    Michelle Laverick Virtuoso

                    So, the only reason you'd need to increase the amount of Service ?

                    Console memory is if you're running some memory-hogging app in it

                    such as a hardware monitoring tool or such).

                     

                    interesting reading - i see the vmware hedged his bets a little - by saying try it and see...

                     

                    I wonder if the allocation is merely "fit for purpose" - in the past we have recommending increasing RAM to COS for things like hardware agents and backup agents.

                     

                    It might be the 276 allocation is enough to cover that...

                     

                    Regards

                    Mike

                    • 7. Re: How big to make the SWAP Partition
                      mstahl75 Master

                      Well, it is easy enough to change from the VIC. Though it takes a reboot.

                      • 8. Re: How big to make the SWAP Partition
                        dwchan Expert

                        So basically, in a nut shell, the SWAP partition that one setup during installation (alone with your /, /boot, /var/log) has no direct correlated with the total phsyical memory of the system (because it is use by the COS, not VM guest).  In addition, from all the comment I read so far, the recommended size is 544, I may just jack it up to 800, should cover 99% of any situation, even if i have like 12 or more so VM that the COS need to manage

                         

                        dwc

                        • 9. Re: How big to make the SWAP Partition
                          MR-T Champion

                          With ESX 2.5 I always allocated 800MB.

                           

                          1) Because I had plenty of physical RAM in the server so didn't miss 800MB.

                           

                          2) Because I loaded the HP insight agents inside the COS which would grab loads of this.

                           

                          As with all these things, it's not an exact science so you have to suck it and see.

                          • 10. Re: How big to make the SWAP Partition
                            dwchan Expert

                            Mr-T bought up a good point.  For server like HP DL585, which use HP Management Agent, wouldn't this effect the amount of COS memory usage on ESX v3.0?  If so, how many more memory or SWAP should one increase?

                             

                            dwc

                            • 11. Re: How big to make the SWAP Partition
                              Michelle Laverick Virtuoso

                              So basically, in a nut shell, the SWAP partition that

                              one setup during installation (alone with your /,

                              /boot, /var/log) has no direct correlated with the

                              total phsyical memory of the system (because it is

                              use by the COS, not VM guest).  In addition, from all

                              the comment I read so far, the recommended size is

                              544,

                               

                              Yes...

                               

                              I may just jack it up to 800, should cover 99%

                              of any situation, even if i have like 12 or more so

                              VM that the COS need to manage

                               

                              I think this is the big bone of contention... A lot of us are coming from an ESX 2.x background - where this important - perhaps there's a danger of applying ESX 2.x practises to ESX 3.x - then again its hard to buck experience.... such as Mr T and the HP Insight Management Agents

                               

                              Regards

                              mike

                              • 12. Re: How big to make the SWAP Partition
                                dwchan Expert

                                when there is a 3rd party/vendor management agent install.  Would you recommend increase the standard SWAP partition eyond the degault 544?

                                 

                                dwc

                                • 13. Re: How big to make the SWAP Partition
                                  Michelle Laverick Virtuoso

                                  Actually, before we loose sight of the bigger picture - memory is king, in fact what we want to aviod is swapping in the first place because we all know it could dire consequences...

                                   

                                  I would take MrT's recommendation of increasing memory for agents... The way I look at it is like this....

                                   

                                  If you 2GB like I do - increasing COS ram has some very painful consequences. If you have 16GB the consequences deminish - because you have more RAM left over after the allocation...

                                   

                                  Perhaps this is a VMware "it depends" answer - the size of your COS allocation depends on what agents you run and how much physical RAM you have... Based on this personally I would follow the 2xCOS rule - which may not be current anymore - but given the defaults is 276MB RAM and 500MB of swap - VMware are still doing it their defaults. I think there's a tacit hint there - don't you?

                                   

                                  Regards

                                  Mike

                                  • 14. Re: How big to make the SWAP Partition
                                    Michelle Laverick Virtuoso

                                    There is another thread that is very tangentally related to this question...

                                     

                                    Here's what one poster has experienced with HA:

                                     

                                    "VMware-Support found out the following:

                                    a) the HA(Legato)-Agent is eating up all the memory and swap of the SC. When it´s all gone, the SC PSOD´s

                                    b) It seems that the VC(or the HA?) can´t handle FQDNs longer than 29 characters."

                                     

                                    http://www.vmware.com/community/thread.jspa?threadID=48234

                                     

                                    Regards

                                    Mike

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