daKrisht
Contributor
Contributor

VMFS and ZFS discussion

Merry Christmas everyone!

I bring this up because of something odd that I noticed in a version of OpenSolaris on ESXi.

I created a new VM and gave it 40GB of a 250GB datastore (known as datastore1 in ESXi). (The total available space on datastore1 is around 140GB (other VMs take up the rest)). I installed OpenSolaris and noticed that I have a few partitions of 22GB each. (combined, they all total about 140GB which is the remaining space of my datastore1)

I guess as someone new to ESXi my questions are:

1) If the disks are formatted under VMFS, wouldn't a file-system like Solaris' or OpenSolaris' ZFS be obsolete?

2) If you wanted to create a pool of disks in ZFS, would that be possible considering you're using physical volumes formatted under VMFS? (i.e. create a 1TB ZFS partition using 4 physical volumes)

3) I'm assuming that even though I created a VM under ESXi for OpenSolaris to use only 40GB it is actually reading the physical volume and using 140GB - am I correct or am I wrong?

Thanks everyone and Merry Christmas!

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2 Replies
weinstein5
Immortal
Immortal

When creating a virtual disk for your Vm you will carve a virtual disk file (VMDK) that will be equal to the size of the disk you create - so creating a virtual disk of 40GB will create a VMDK file that is 40 GB in size -

1) If the disks are formatted under VMFS, wouldn't a file-system like Solaris' or OpenSolaris' ZFS be obsolete?

No they are still required - because that is the format of the files system stored inside the VMDK file

2) If you wanted to create a pool of disks in ZFS, would that be possible considering you're using physical volumes formatted under VMFS? (i.e. create a 1TB ZFS partition using 4 physical volumes)

depending on how you want to create the virtual disks -

3) I'm assuming that even though I created a VM under ESXi for OpenSolaris to use only 40GB it is actually reading the physical volume and using 140GB - am I correct or am I wrong?

No - the virtual disk that you created will only be 40 GB in size and that means you will only have 40 GB to use

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wings7351
Contributor
Contributor

Hi, I am running into a situation (not that I prefer this) where I will probably need to create ZFS pool on top of VMFS. Becuase ESXi does not support physical disks that are directly attached to local computer, I would have to create datastore with the whole disk, then create virtual disk on top of that, then present it to Nexenta and create ZFS pool accross three virtual disks from three datastores.

Is this the only way to acheive the ZFS pool with direct attached disks? (other than creating ZFS pool and attach to ESXi via iSCSI)

Thanks.

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