I just lost a 2 TB iSCSI target which had around 1 TB of data inside. I have now recovered it and wanted to share my experience so you won’t waste your time if this ever happens to you.
So my iSCSI target’s alias was “recovery” and its iSCSI Qualified Name (IQN) was “iqn.2013-03.com.wdc:wdmycloudex2100:recovery”. It had no security (choosed “None” instead of “CHAP” on the “Security” page at creation) and was sized at 2 TB.
I don’t know how the EX2100 lost it nor when, I just suddenly found out that it was not listed under “iSCSI Target List” (Dashboard > Storage > iSCSI). Upon checking from Windows, it was not listed under “Disk Management” as well, so something was wrong…
I created another iSCSI target named “test” with no security and with a size of 1 GB, then clicked on “Details” to find more about its image file; which was showing exactly as “Volume_1/.systemfile/iscsi_images/test.img”.
I connected to the EX2100 through SSH to see if there was also an image file for my previously created (and now lost) iSCSI target which had the alias “recovery”. I used the command below to search for it. You can also see that it was found in “/mnt/HD/HD_a2/.systemfile/iscsi_images/”;
root@WDMyCloudEX2100 root # find / -name ‘recovery.img’
root@WDMyCloudEX2100 root #
I used the command below to see its size;
root@WDMyCloudEX2100 root # ls -l /mnt/HD/HD_a2/.systemfile/iscsi_images/
-rw-rw-rw- 1 root root 2000000000000 Oct 21 04:29 recovery.img
-rw-rw-rw- 1 root root 999998440 Oct 26 02:00 test.img
root@WDMyCloudEX2100 root #
You can see that the size (2000000000000) was matching for my 2 TB iSCSI target, which looked hopeful at this point.
So what I did at this point was to create a new iSCSI target with the same alias (“recovery”) and hope that it would somehow register it with the already existing iSCSI target without over-writing it… Since I was using RAID 1 with 2 x 4 TB hard drives, I wouldn’t be able to set the new one’s size at 2 TB as well (received an error saying that the target size was too large as I didn’t have that much space left), so I just set it to lowest possible, 1 GB instead, and clicked on “Apply”!
Voila! Guess what? My iSCSI target re-appeared back on the “iSCSI Target List” with a size of 2 TB! Next step was to try and connect to it through Windows to see if data was intact, which indeed was!
So in summary, if you lost an iSCSI target, you might be able to recover it by creating another one with the same alias - and seems like size doesn’t matter at all. However, I would always suggest you to contact WD’s technical support before trying this on your own, if your data is important. This action plan I shared resolved my problem but it might not on your case; you might even corrupt your critical data if you’re unlucky!
Finally, I don’t know what caused this issue to begin with, but it made me a little bit nervous and now I’ll have to think twice before using an iSCSI target to store important data. Who knows if I’ll be this lucky the next time!?