Esxi 4.1 on HP DL360 G7 - strange problem with disk space

[xcieja]

Hello All,

i am running ESXi 4.1 on HP DL360 G7 with two disks working as RAID1- disk size 274 GB.

I am installing VMs with Windows XP.

Initially after creation all VMs i had 4GB free disk space. Yesterday i could launch all of them.

Today morning i wanted to finish installation of last two (from 10) VMs and i got following info:

"Insufficient disk space" - i checked disk space via df -h and vmfs3 took 100%

In my case it seems as vmfs3 requires more and more space.

Now i have recreated last two VM and i have around 16 GB free.

How much disk space should be free in order to avoid such problems ???

[idle-jam]

try to drill down where did the space gone to, did you have snapshots turn on which it will grow from time to time when there are changes on the virtual machines..

[xcieja]

Hello,

Honestly i don`t know what i can do ...It looks as follows (after re-creation of two VMs):

~ # df -h
Filesystem                Size      Used Available Use% Mounted on
visorfs                   1.4G    327.5M      1.1G  23% /
vmfs3                   274.3G    256.6G     17.7G  94% /vmfs/volumes/4d421cec-0               0dc1fe4-5193-78e3b5188a46
vfat                      4.0G      2.8M      4.0G   0% /vmfs/volumes/4d421cd6-5               74cf2b4-bb9f-78e3b5188a46
vfat                    285.9M    140.7M    145.2M  49% /vmfs/volumes/2da668ef-4               0e5d96b-90bf-855ddb9c5547
vfat                    249.7M      4.0k    249.7M   0% /vmfs/volumes/ffaa8873-f               bb7c87d-af1d-d6ffde720d39
vfat                    249.7M    107.4M    142.4M  43% /vmfs/volumes/00042272-a               42667ab-6b88-8b0c2f23ec87

I am new to ESXi administration in case of snaphots and so..

Ok -i have checked how snaphots work:) But i don`t see if it is turned on or off...

I have checked also this post: http://communities.vmware.com/message/1825170?tstart=0 (i think similiar problem)

But still don`t know how to manage with snaphots.

I a,m using Esxi 4.1 free.

[idle-jam]

try see this: http://searchvmware.techtarget.com/tip/Troubleshooting-VMware-snapshots

[xcieja]

Ok thank you -i will go throgh and in case of questions i will post them here.

Is thare any simple way to check if snapshots are turned on or off ??

Under every VM i have only that:

[idle-jam]

this shows that the VM has no snapshot, btw when you powered up a VM it will create a swap file that is a large as the assigned virtual memory. other than that the vmfs would not have any space required.

[xcieja]

Do you mean that every thime VM is powered up it needs the same amount of virtual memory to run as it has assigned ???

Let`s take an example:

i have 10 VMs -each has disk size of around 20 GB

So each time one of these machines is powering up it needs 40 GB (20GB +20GB) ???

So in my case if i have total disk size 274 GB to run all VMs i would need 400 GB disk size ??

Is that correect ??

[idle-jam]

it's the virtual memory so if it's assigned 2GB RAM, then it's 10GB VMDK + 2 vSWAP so total is 12. can you look at the virtual machine folder and see where other files are using up the space ..

[xcieja]

Hello,

yes every machine is assigned with 2GB memory.

But how did you compute that ??What is correlation of 10GB VMDK and 2GB of memory ??

How can i calculate it ?? Also vSWAP...

Is there any equanation or described somewhere ???

i prefer to understand it rather than only keep in mind that value...;)

Also it seems to be strange to me since yesterday i had only 4GB disk pace free  and i checked i was able to run all of the machines...

[V12NPro]

SWAP file is always the amount of memory configured. So, if you configure memory for VM to be 4GB, the swap is also going to be same size.

You can find this information in the vsphere 4 maximums and best practices guidlines docs:

http://www.vmware.com/pdf/vsphere4/r40/vsp_40_config_max.pdf

[xcieja]

Hello,

ok, but i still don`t see why yesterday i could launch virtual machine with only 4GB free space left and 2GB virtual memory and 20 GB disk,

but today i was not able...

I can not see how it is linked with that what was said by idle-jam.

The most important question:

i have 10 VMs -ech 2GB memory and 22 GB disk size.

How many disk space should i have left in order to avoid that problem ???

Regards

[V12NPro]

10 VM at 22GB each? Whats the size of each VM?

[xcieja]

Ok, let`s do it other way...

I am going to install 10 VMs -each of them 22 GB disk size and 2GB of memory.

How big disk should i have to avoid problem mentioned in earlier posts ???

Correct me if i am wrong: 10x 24GB (22GB disk + 2GB vSWAP) = 240 GB

Is that correct ???

[V12NPro]

That sounds about right but if any VM configured memory changes, the numbers will change.

[xcieja]

Is that process somewhere described ???

And the second -those requirements are only relevant to process of powering up the VMs, right ??

[SuryaVMware]

You will need little more than that.

I am assuming you are talking about 240GB of disk/datastore just to host the VM, and you have a different disk you have installed the ESX/i server on it.

In any case you need a disk bigget than 240GB to host 10 VMs (with 22GB HDD + 2 GB MEM), that is because when you format a disk as VMFS volume you will loose about 600-800 MB of space for VMFS metadata. In addition to that you need little space for your configuration files and log files of the VMs.

I would say have atleast 10GB of free space on top of what you need for VM's disk + Swap file. (i.e considering you are never going to use snapshots)

Alternatively, you can consider using Thin disk, while creating the VM, Thin disks may be little slower compared to thick disk.

Hope this helps,

Regards,

Surya