Windows iscsi troubles

[jamiejunk]

I have a freenas zvol exported via iscsi to a windows 2008 r2 server.
The windows server is showing 13.9tb in size. 6.04TB used and 7.95 free. So that's fine.

The freenas server is showing:

Code:

[root@freenas] ~# zfs list -t volume
NAME          USED  AVAIL  REFER  MOUNTPOINT
tank1/iscsi2  15.2T  1.89T  15.2T  -

I'm not taking any snapshots:

Code:

[root@freenas] ~# zfs list -t snapshot
no datasets available

So I'm not sure why freenas is thinks a bunch of space is being used up. Anyone have any thoughts?

 

[cyberjock]

When you create a zvol it will use 100% of it's space right off the bat. Then your zvol, which is only a block device, is being handled by your Windows machine.

zfs list is telling you how much pool space you have free while Windows is telling you how much space you have available in your block device. The two are not the same and they shouldn't be the same.

Unless you have a need for a block device you should have stuck with doing CIFS sharing. if CIFS sharing could do what you want, you should have used that so that you actually have total use of your pool. As it stands now, you've got roughly 8TB of disk space allocated to your zvol that isn't storing data. That's what people call "wasted space".

Also, your pool is 87% full, which is not recommended for iscsi devices. The recommendation is 50% full...

 

[jamiejunk]

This is for our surveillance system. The vendor Milestone want's iscsi and not CIFS for archive data.
So the 8TB of "Wasted Space" will be eaten up soon enough with video footage :)

You say my pool is 87% full. But also say when I create a zvol is uses 100% of it's space off the bat.

So if i understand correctly the following is true:
If I want to create a zvol for use with iscsi I should only use 50% of my pool. So in order to have 15T of iscsi storage I should have 30T of disk space available?

 

[jamiejunk]

Also could you point me to the documentation that mentions the 50% limitation for iscsi? Googling has me coming up empty.

 

[cyberjock]

It's not in FreeNAS' manual because its a ZFS thumbrule. It has been mentioned dozens of times in the forum though. ;)

 

[jamiejunk]

If I want to create a zvol for use with iscsi I should only use 50% of my pool. So in order to have 15T of iscsi storage I should have 30T of disk space available?​

 

[cyberjock]

Per the thumbrule, yes.

 

[jamiejunk]

ouch!

Thanks for the responses.

 

[cyberjock]

Choose your protocol choose your fate.. Every protocol has it's pluses and minuses. Sounds like you might not have been fully aware of the advantages and disadvantages of each. ;)