tag:blogger.com,1999:blog-1883838730047505834.post8616302574424711005..comments2023-05-12T03:53:54.058-04:00Comments on Cranium Tales: VMware Memory ExplainedHanshttp://www.blogger.com/profile/16671649809989349947noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-1883838730047505834.post-23055436215590244652013-03-31T15:13:43.498-04:002013-03-31T15:13:43.498-04:00The explaination is incorrect. You should read the...The explaination is incorrect. You should read the whitepaper provided by VMware to understand Shared memory. It is the memory shared with 2 or more VMs instead of 'memory not in use and can be shared'Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1883838730047505834.post-983949343975472472010-09-09T07:20:31.404-04:002010-09-09T07:20:31.404-04:00Thanks ....Thanks ....Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1883838730047505834.post-27178899638185625552010-07-21T06:27:03.603-04:002010-07-21T06:27:03.603-04:00Great post! It's most useful. Thank you very m...Great post! It's most useful. Thank you very muchRelicaryhttps://www.blogger.com/profile/18066084626805735374noreply@blogger.comtag:blogger.com,1999:blog-1883838730047505834.post-35851265419151387982009-08-11T17:37:44.223-04:002009-08-11T17:37:44.223-04:00Hi Hans,
I understood that memory shared is block...Hi Hans,<br /><br />I understood that memory shared is blocks of memory which are identical between guest VMs on a host, and are 'de-duplicated'.<br /><br />For example, if you have multiple Server 2003 VMs running on a host, chances are a small portion of their memory will be identical as they are running the same OS. The ESX host thus stores only one instance of the memory block rather than multiple copies of the same memory block, and the guest VMs have pointers to the 'shared' memory. This saves physical memory on the host as it 'de-duplicates' memory.<br /><br />The Available Physical Memory you see on the task manager view is just memory which is not being actively used by the guest and is not related to Memory shared.<br /><br />This paper explains it well: http://communities.vmware.com/servlet/JiveServlet/download/2380-17273/VI+3.5+Memory+Statistic+Definitions.pdf<br /><br />MattMatt Rayhttp://matt.ray.co.uknoreply@blogger.comtag:blogger.com,1999:blog-1883838730047505834.post-20171648454030557052009-06-29T20:48:02.549-04:002009-06-29T20:48:02.549-04:00Juan,
Each environment and VM is different, so so...Juan,<br /><br />Each environment and VM is different, so something that works for me may not necessarily work or be best for your environment. I monitor the memory resource usage while my VM's are under a typical load and keep the utilization under 80%. This allows me to over subscribe memory on the resource but allows for spikes in memory usage when needed. If the utilization gets too close for my comfort, all I need to do is VMotion hosts to other resources.Hanshttps://www.blogger.com/profile/16671649809989349947noreply@blogger.comtag:blogger.com,1999:blog-1883838730047505834.post-31119498083371789322009-06-29T13:30:35.499-04:002009-06-29T13:30:35.499-04:00Great tip. Thanks for finally rounding up all this...Great tip. Thanks for finally rounding up all this info. Did you stumble on any good docs that provide good general practices for allocating physical memory on your server to all the virtual machines? Something formulaic?Juanhttps://www.blogger.com/profile/03360661167520606683noreply@blogger.com