Planning Drive Usage

[uturn]

Hello, our Sun x4100 2cpu 8GB Ram is targeted to have ESX 2.x installed. The machine has two 73 GB hard drives (configured as mirrored drives). If we are only looking for a single guest VM (win 2k3 server) at this point, how much drive space can we expect in this guest, once all of the partitions have been created to support the ESX host?

From the manuals, it looks like we should expect about:

14GB ESX OS

8 GB RAM overrun

~200 MB misc

Overall, can we count on approx 23GB taken up w ESX related infrastructure - leaving about 73GB - 23GB = 50 GB for the guest machine? Assuming I want to get as much possible drive space on this single host, but want to have some in reserve in case we add another VM (which won't happen for six months or so) are there any recommendations out there?

Thanks for any suggestions

[surferdave]

I really depends on what you will be running on your Windows guest. I have several "low end" Windows VMs running that use only 4GB per VM, but they are not using much hard drive resources. What tasks will the Windows guest be performing? If you allocate the minimum required hard drive space, you can always add either an additional virtual hard drive or add an extent to the existing hard drive.

[uturn]

thanks for the follow up Dave (surfing in Texas?)

you answered part of my question (i.e., how much space could I reserve at a minimum for an additional VM).

The other part of my question can probably be best boiled down to this:

After I install VM esx 2.x on our machine (see machine specs above, since physical RAM makes a difference in swap reserve) - how much space should i have left over (i.e., for my guest VMs)?

Thanks again!

[Texiwill]

Hello,

This is really an ESX 2.x question and there is a separate forum just for that. However, to answer your question, how much vSwap depends solely on if you are going to overcommit memory or not. By default when you add vSwap it will default to 8GBs. Look at your memory as follows:

1GB for SC and VMKernel

Leaving 7GBs for VMs.

You could allocate 1 3.6GB, 2 3.5 GB VMs, 3 2GB VMs, 7 1GB VMs, 14 512KB VMs (and many other combinations) before you overcommit memory. Once you overcommit memory you have to increase vSwap.

Now, if you are only running 1 VM but want to create many more to run you still need vSwap even to create the VMs. In essence as much memory as you assign to all VMs (running or not) must exist either in physical memory or vSwap.

Best regards,

Edward

[uturn]

thanks for the reply texiwill... actually, i should have been more specific.

The other part of my question can probably be best boiled down to this:

After I install VM esx 2.x on our machine (see machine specs above, since physical RAM makes a difference in swap reserve allocated on hard drive - so assume i am just using 8 GB for now) - how much [b]HARD DRIVE SPACE[/b][/i] should i have left over (i.e., for my guest VMs)?

Thanks for the help.

[kix1979]

Based on how your setup is with your partitioning for 50G VMFS you could fit 5 VMs on there realistically.

40G = 8G per VM * 5 VMs

2.5G = 5 VMs * 512M swap

7.5G = Leftover for Snapshots, logs, etc...

50G Total

Obviously you could give them more memory and have them swap, and that would eat into space as well thus decreasing the overall space leftover. However, if you run 6VMs that would only leave 2G of space for swap, logs, snapshots, etc... and that is not enough. A good rule is always leave 5 - 10% free for snapshots/logs/who knows what may need it...

[uturn]

Thanks kix,

So just to clarify (based on your response and my requirements) ...

Machine Specs: 2 cpu, 8Gb ram, 73 GB HD (mirrored raid)

Objective: run 1 VM on there for now, eventually may want a second VM.

73GB total drive space

less 8G swap

less 7.5G snapshots, logs, etc.

= ~49G for VM

This should leave ~49GB for my VMs? So I should theoretically have enough room to run my main VM w 40GB hard drive space and reserve 9GB drive space for a future VM?

Or am I missing something?

Mainly, I would like to know how much drive space I would have left to allocate for my VMs (i will only run 1 for now), given 73GB hard drive available and using 8G for swap (i.e., how much space is required/recommended for ESX OS, logs, snapshots, etc.).

Thanks

[Texiwill · Accepted solution]

Hello,

73GB - 8GB (installation space required, but this is still low) = 65GB

100KB for vmcore

and 64.9GB left as a VMFS-2 partition.

Out of the 64.9 GBs, 8GBs will be used for vSwap, leaving 56.9GBs for VMs, REDO logs, and sundry other files. If you are never going to overcommit memory then the 8GBs for vSwap can be ignored as well.

Remember you are discussing ESX version 2, not 3. So there are no snapshots, no logs stored on a VMFS. Logs are in the Host /home directory and snapshots do not exist. Of the 8GBs of the default ESX install 2GBs should be assigned to /home to alleviate stress there and 2GBs assigned to /var to alleviate overflowing logfiles.

However, if you are discussing VI3, that is another story completely.

What it boils down to is that you will either have roughly 64GBs or 56GBs for VMs if you use 8GBs for the base install, more if you use less.

Best regards,

Edward