Provisioning iSCSI LUN confusion ?

[ITEngineer]

Hi All,

I'm using QTS 4.3 and I'm confused of which selection shall I select to create new 2 TB iSCSI LUN for my Windows Server 2012 R2 ?

If I select the first choice I can see 34 TB is free.



But ifI select the second choice, there is no free disk space ?



How can I proceed with the 2 TB iSCSI LUN that I can resize later on in the future without losing any data in it ?

Thanks in advance.

[storageman]

What size and type of volume is already in the pool?
Sounds to me like you created a thick volume so have used up all the pool space.
In other words you can only create a LUN inside a volume then (e.g. DataVol1)

I've seen your posts before, you seem to be struggling understanding the differences between thick and thin volumes and block and file LUNs.

File LUNs sit inside volumes and can be thin provisioned or instant allocation.
Block LUNs take up pool space separately to volumes and can be thin provisioned or instant allocation.

[ITEngineer]

Hi StorageMan,

Thanks for sharing, so is there any diagram which shows the various type of LUN, Pool or mode that QNAP supports ?

[ITEngineer]

So in the screenshot above, it shows that I can create image based LUN for iSCSI, what's the caveats or pitfalls when presenting this LUN through Windows based guest OS (VM).

[storageman]

Hi StorageMan,

Thanks for sharing, so is there any diagram which shows the various type of LUN, Pool or mode that QNAP supports ?

Can you see the difference here?

And remember if your volume is thin, it is does not reduce free space from the pool until data is written to the volume.
Therefore in your question in might have been possible to create a block LUN separate to the volume because the pool space isn't used up yet.

http://docs.qnap.com/nas/4.3/cat2/en/in ... anager.htm

basicstoragemanagementarchitecture.png

[storageman]

So in the screenshot above, it shows that I can create image based LUN for iSCSI, what's the caveats or pitfalls when presenting this LUN through Windows based guest OS (VM).

Usually performance

[ITEngineer]

So in the screenshot above, it shows that I can create image based LUN for iSCSI, what's the caveats or pitfalls when presenting this LUN through Windows based guest OS (VM).

Usually performance

So is it faster by iSCSI or NFS share given the same one Gigabit link ?

[storageman]

No idea, test it.
Different environments different results.