Short one today but hopefully useful to those of you running Synology storage devices. An application error drew me to this issue when a storage location disappeared overnight. Checking on the location I noted that it was an iscsi target based on a synology NAS. I had noted recently that an update for DSM was available and was about to install it when I realised it was already installed!!
At 6AM this morning the update had auto-applied !! Thanks Synology !! Version DSM 6.2.3-25426 to be specific had been installed. I rebooted the unit and the vm that had this as a target to see if the issue might just have been a timing issue – as the vm in question had a backup running at around that time.
Unfortunately that didn’t clear the issue and the vm reported “Target Error” when I manually tried to connect from the ISCSI control panel in Windows. On checking the Synology iscsi manager for the first of two targets – I noticed that under service status – another device which shares access to the iscsi targets was listed – but not the one I was having problems with.
On checking the target’s configuration (select Action / Edit from the menu above it) – the option “Allow multiple sessions” was actually unselected – and can only assume that the update was responsible. Enabling this (and understanding why there should be multiple sessions from the two machines in question) allowed the targets to be reconnected. Checking that the correct drive letters were assigned – it was noticed one of the iscsi targets was shown as offline in Disk Management and simply right clicked and brought it back on line.
The release notes for that version are here