Amount of RAM doesn't add up

[ValdasAD]

Hello,

I'm evaluating ESXi 4.1 and I'm confused about the amout of RAM available on Resource allocation tab. I get only 2315 MB instead of 4 GB that are physically available on that machine. Please see the screenshots attached. The ESXi itself is using 905MB of RAM without any VMs yet. That's strange..

Could someone shed some light on this?

Thank you,

Valdas

[idle-jam]

the ESXi itself will also need RAM to power the virtualization 😃

[ValdasAD]

OK let me clarify my question.

On the summary page i see 906 MB of used memory. 2315 are available for allocation. So that's 906+2315=3221MB . Where did another 875 MB go?

And another question

On configuration->memory i see that 3721 MB are available for Virtual machines and 374,2 MB are used by the system. Why does it show 374 MB for system and actually uses 906 (as shown in summary page) ?

Thank you,

Valdas

[BRiley1]

Are you using memory reservations on your VM's?  That can cause even more overhead than your typical VM uses.

A good way to go and see exactly what is using your memory is using ESXTOP.

In case you don't know how to do that, just type in ESXTOP from Tech Support mode, or SSH.  Then type the letter "m" to see the memory stats.

There, you'll see everything you need to see about memory.  Hit "f" to add, or remove fields, and if you get lost hit "h" for help.

For more on ESXTOP, hit this page:

http://www.yellow-bricks.com/esxtop/

[ValdasAD]

Thanks for the tip BRiley1, i'll try to play with esxtop and get back with any interesting findings.

Valdas