iscsi sector sizes - physical vs logical presentation

[kktwenty]

I am using a qnap 1273U-RP with 10x 4TB ironwolf drives. 4TB ironwolf drives should be 512e logical/4096 physical drives. I have created a pool with 10x drives and a block level LUN and an ISCSI target. The target is being picked up by an MS server 2016. However, the LUN is being presented to the server as having 512 logical and 512 physical sectors. This is a problem for me. The QNAP is being used as a target for replication, replication requires identical sector sizes or it wont replicate. Since the source is being presented by a dell MD3200 with 4TB drives (512e and 4096), the MD3200 is correctly presenting its LUN as 512 logical and 4096 physical.

How can I get the qnap to present the drives correctly? Why is qnap presenting 4096 physical drives as 512? I assume this is due to some kind of emulation. Is there a CLI to change this?

[Trexx]

I don't believe under QTS you are going to be able to change it. Since most drives use 512e logical due for OS compatibility, QNAP likely chose that due to the varying kernel level of some of their HW.

I don't know if QTS 4.x beta (which updates the kernel) changes that or not (I haven't played with ISCSI under it yet).

Qnap's ZFS based Enterprise line DOES support definable block size for iSCSI and might be a better fit for your use case.
https://www.qnap.com/en/how-to/faq/arti ... iscsi-lun/

[Trexx]

I just checked and QTS 4.4.x does have an option under advanced settings to choose 4k block size when creating a thick iSCSI LUN from my storage pool.

[kktwenty]

I tried the 4k block size but this changes both logical and physical to 4k, this presents the same problem. 512e is absolutely fine, it is the misreporting of the physical that trips up the replication. Im not sure why the block LUN changes the physical.

I have a feeling this is not possible under qnap so this poor array will be relegated to backups I think.

[Trexx]

It may be possible under Enterprise Qnap’s (which are ZFS based), but evidently not the Consumer/SMB Qnap that you purchased.


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[storageman]

What model drives are they?

BTW what replication tool worries about block size. Not seen this.

https://support.microsoft.com/en-gb/hel ... in-windows

What does the "fsinfo" say?