Concurent iscsi access

[jim71]

Hello,

I was wondering if it is possible to have 2 clients accessing the same iscsi disk concurently ?
I mean one in RW mode and the other in R only mode, using 2 different chap user auth group.

This is currently node possible in the gui as you cannot define 2 extend with the same path or
2 targets using the same extend. But I am rather new to iscsi and do not know if it is
a gui limitation or by design for iscsi ?

What is possible is to define 2 users in the same auth group, but then you end up with your
2 clients having both RW access. This works well as long as you do not try to write on the disk
with the second client, if you do you get NTFS error on the disk, so this is too dangerous.

I am using N4F 9.2 with zfs volume for my iscsi disk, and have my home PC iscsi connected to these disks.
Then the idea is to have my backup serveur with a read only access on the disks for backup purpose.

[marvias]

Hi it is possible but you have to have cluster-aware filesystem on that volume. For example this perfectly works with ESXi vmfs datastores. But NTFS or ZFS are not cluster-aware, as they load filesystem metadata in ram and dont expect anyone else to modify them (they dont load them again until next mount). In linux, e.g. GFS2 must be used.