SOLVED VM's...

[Altec]

Ok, foremost thank you in advance for any help with this issue. I've watched so many you tube vids and google and I became good friends...well sorta.

I am setting a new VM to host my Unifi Camera software. I have created a new zvol with 1TB of space. I was able to create the VM, install the software and all was good...or so I though. With in 10 minutes of the software running I kept getting disk space errors (full disk). There is no way I could have filled up 1TB of space in 10 minutes.

So looking at my drive pool I noticed something odd, It states I have used 1007.82 GB of space. So I started over thinking I messed up something. I created a new zvol and right off the bat before I even created the VM again, it states I used 1007.82 GB of space. Welp here I am asking the pros where I went wrong...I've attached a screen shot of my system and the pool. Hopefully someone can help me out.

Matt

 

[Heracles]

HI Altec,

For ZFS, space that is reserved is actually marked as used. So here, the entire space for your zvol is reserved, so it is marked as used in the WebUI.

A ZVol is a space that is presented as a raw block device. So now, you need to connect that zvol to another system and that system will have all of that space for it to use as needed. You can then format it and use it.

So Yes, the 1TB of your zvol is used space in the pool, but the entire space inside that zvol is free to use by any system you will connect to it.

Hope this explains what you see

 

[Altec]

Yes, I understand it gets marked as used in the pool because it gets allocated.

I created the VM, using that 1tb volume and installed Ubuntu 18 with the iso, just like any other VM. Once the VM was up and running I started getting a drive full error. I was nowhere near 1TB of space usage. I could no longer write to the disk.

 

[Heracles]

What was giving you that error ? What was the exact error message ? What is the space used INSIDE the zvol ?

We need more info to help you on that one...

 

[Altec]

So I tried something different...

During the install process of Ubuntu, Instead of picking Using the entire disk and setup LVM, I just picked use entire disk. (screen attached).

I have always used the one with LVM (I'll be honest I have no idea what LVM is). It seemed to have worked. I am no longer getting space errors and df doesn't show a full disk...

Can anyone explain what LVM is?

 

[Heracles]

Hi,

LVM is for Logical Volume Manager. It allows you to re-size partitions instead of having the hard and fixed partitions typical of old DOS formatting (the 4 primary partitions or 3 primary and 1 extended that could be sub-divised but not booted up).

Glad you are now up and running,