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Limit disk buffer usage in SLES 11SP2 to allow more efficient memory overcommit on esxi host

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http://unix.stackexchange.com – When running VMs on an ESXi host, you can overcommit the memory. Example: host == 20GB physical RAM The amount of RAM allocated to each VM is VM1 == 10gb VM2 == 10gb VM3 == 10gb VM4 == 10gb The result is even though there is only 20GB of ram available, We have actually allocated 40GB of it. There is no problem with this if each machine uses and average of 5GB of "active" memory (inactive memory is swapped out in a few different manners). The issue is, VM1 does a big file operation, the kernel writes an additional 5GB to it's RAM. As this is just written, the esx host considers it as ac (HowTos)

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Submitted by missing on 01/18/2013

Stories similar to Limit disk buffer usage in SLES 11SP2 to allow more efficient memory overcommit on esxi host

How much can I overhead the physical memory of my host assigning memory to my guest machine?

Example:

Host physical memory:10 GB

Is it acceptable for example assigning 2GB of virtual memory to 7 machines for a total of 14GB ? How much can I overcommit the memory ensuring balooning and other host memory freeing technique works fine?

We are server with 48 GB RAM.( We have installed ESXi 4.1 )

For each VM we are allocating 4GB of memory. Since the server is having 13 VM, My manager thinks that i am doing wrong thing.

I am going to explain them that it will actually manage by itself.

Internal Storage 9 weeks 1 day ago

I have a Sony Xperia TL with an Internal Memory of 10GB. Recently it's been telling me to transfer date to an SD Card which I don't have on my phone because I feel 10GB is sufficient for me at the moment. This morning it told me my Internal Memory is 75% full. But when I checked the settings on my phone is said I still had 9GB of the 10GB free. Could someone help with this? Thanks!

I am thinking about using duplicity over rsync for doing backups (to a remote host) of various things but I have heard that duplicity requires a good deal of temp space.

Does anyone know how much temp space you need compared to how much data you are backing up to a remote host?

For instance if I am backing up 10GB, do I need 10GB of available temp space? 20GB? 50GB?

Thanks,

Casey

I have the following questions regarding Linux memory:

I know that the active memory is the portion of memory which is most frequently accessed. But can someone explain me how linux considers a memory location to be utilised for active memory or inactive memory. What all components does active memory comprises of ?

I have a VMware ESXi 3.5 hypervisor host with a bunch of guest VMs on it.

Yesterday, I had a ESXi server working. Total memory required by the deployed virtual machines is higher than the physical RAM. The disk also has a few Gigabytes of free capacity.

Today my server stopped normal operation!

I have an application that reserves a contiguous memory block using VirtualAllocEx on Windows with the MEM_RESERVE flag. This reserves a virtual memory block, but does not back it with a physical page or page file chunk.

Say I have an ESXi (5.0) host that runs a Linux distribution which hosts iSCSI targets, which contain the images for other VMs which the host will run. When it's used, I'll start the host first, then the iSCSI server, and then refresh all storage targets/HBAs in order to see the provided shares as online. I know it's a strange puzzle-box solution, but I was told to implement it.