Volume Size

[oz07]

Hi,

I'm testing FreeNas 9.1 on a VM. I have created a ZFS volume RAIDZ with 5 disks of 4GB.
I should have a volume of ~16GB but Freenas show me a volume of 7,8GB.

What's wrong ?

 

[cyberjock]

2GB per disk is assigned to swap space.

 

[oz07]

Thanks for your reply
Is it a FreeNas specifications ? I have tested Nexenta in same conditions and I have a "normal" volume size

 

[cyberjock]

It's the default setting in the GUI. See the FreeNAS manual to change it. In short, this issue rears its head when you do small disks like you did, but when you have 2TB drives you won't notice 2GB missing.

 

[oz07]

Good to know. I agree with you.
Thanks.

 

[viniciusferrao]

Just a question: this swap space is ever used?

 

[cyberjock]

Normally it shouldn't be used. But you should still keep it around. You won't miss the 2GB on a 2TB+ disk.

 

[survive]

Hi viniciusferrao,

Like cyberjock said, in normal use your system shouldn't touch the swap file. The benefit of these 2GB swap partitions comes in when you have a situation where it would need to swap it has somewhere to swap to. The swap partitions also act as a hedge of sorts when you replace a failed drive.....if the new drive is just a touch to small you wouldn't be able to use it, but FreeNAS can use some of that swap space that would usually be assigned to the swap partition to give the data partition enough room to be added to the pool.

-Will