VMware Cloud Community
metebalci
Contributor
Contributor

ESXi 4 hypervisor memory footprint/usage

I have seen some posts related to memory footprint issues about ESXi 4 but it is still not clear to me. I have installed ESXi 4 on a PC with 4GB of memory. On vSphere Client, I see only 2.3GB of memory is available for use by guests. Does hypervisor alone consume 1.7GB of memory ? Isn't it a little bit too much ? I guess at least one point of using a baremetal hypervisor is making maximum memory available to guests if not all, if hypervisor alone consumes 1.7GB of memory, why should I use a baremetal hypervisor ?

Thanks.

Mete

Reply
0 Kudos
5 Replies
AntonVZhbankov
Immortal
Immortal

ESXi works perfectly with memory volume up to 1TB, and 1.7GB is a reasonable price even for 16GB RAM due to memory saving technologies called Transparent Page Sharing and Memory overcommitment. ESXi will save you much more memory than 1.7GB.

For example, I have now ESXi with 18GB RAM. Memory usage is about 17GB, Memory Granted is 28GB (sum of all running VMs memory) and TSP saved me 13.8-0.4GB = 13.4GB of RAM. VMs are running just fine, no issues.

If you have a little amount of memory like 4GB total, I agree, 1.7GB just for hypervisor is a little expensive, but you can install ESXi 3.5, it has smaller memory footprint and has almost identical functionality as ESXi 4.


---

VMware vExpert '2009

http://blog.vadmin.ru

EMCCAe, HPE ASE, MCITP: SA+VA, VCP 3/4/5, VMware vExpert XO (14 stars)
VMUG Russia Leader
http://t.me/beerpanda
metebalci
Contributor
Contributor

Thank you for clear answer.

According to what you said about that technologies, for example, on a 4GB machine, where available is 2.3GB as I said, can I have 4 guests each having lets say 1GB of memory ? It seemed to me that I cannot even start a guest if the memory requirement cannot be fulfilled.

Mete

Reply
0 Kudos
J1mbo
Virtuoso
Virtuoso

Might be worth using v3.5, the footprint is very much smaller.

metebalci
Contributor
Contributor

OK, I am returning back to 3.5 if I dont have much memory like 4GB.

Mete

Reply
0 Kudos
AntonVZhbankov
Immortal
Immortal

Yes, you can start 4 guests with 1GB memory each. But you should be absolutely sure that total memory usage in these VMs will be less than 4GB. Otherwise intensive swapping will start and affect performance.

This enables you to run VMs with big memory demands if memory usage is not on the same level during working day.

For example, you can run OLAP & OLTP servers on the same host. OLTP will use memory intensively during working hours, and OLAP will use memory to generate reports on the night.


---

VMware vExpert '2009

http://blog.vadmin.ru

EMCCAe, HPE ASE, MCITP: SA+VA, VCP 3/4/5, VMware vExpert XO (14 stars)
VMUG Russia Leader
http://t.me/beerpanda
Reply
0 Kudos