[Solved] iSCSI with Synology NAS

[mtthwbrd]

Hi everyone,

So I until a while ago had a nice setup whereby my virtual HDDs were on my Synology NAS, I used the iSCSI target to link the machine to my virtual HDD for a Windows machine and an Ubuntu one. Something has broken and I am just getting the messages saying the virtual HDD is inaccessible, I have checked the Synology end by connecting to the iSCSI targets with another initiator and everything is working fine, however when I try to attach via Virtualbox, no luck..
I think I have covered all of the bases when it comes to the basics, any assistance would be great..

Matt

[michaln]

Something has broken and I am just getting the messages saying the virtual HDD is inaccessible

At this point you know infinitely more about the problem than anyone else.

[mtthwbrd]

Thanks for the help... Found the problem, solution was using the --lun option to point Virtualbox in the correct direction..

Hi Dan,

I struggled with this same problem for most of today. I finally figured it out for myself. Maybe what I did can help you, even though it has been a month since your post.

First, I saw someone post online that you should only attach an iSCSI disk to either a VM's IDE controller or a SCSI controller. They said that a SATA controller always gave them problems. I'm not sure if this is true as I still had the problem after I created a SCSI controller in my VM and attached the disk to it. I can't recall where I saw this posted.

What really seemed to be causing the problem for me was not specifying the "--lun" option on the command line (even though it's listed as optional in the docs), or when I did specify it, I had the wrong value.

You see, I was trying to get my VM to connect to an iSCSI disk on my Thecus N5200PRO home NAS unit, and on the version of the NAS firmware I have you cannot specify the LUN number (nor does it display it). I found online that it does seem to specify the LUN numbers starting at zero and increments by 1 for each iSCSI target you create. So my problem was that I specified either no --lun option (I think that causes VBox to default to 0), or when I did specify it, I used "--lun 0" or "--lun 1". Turns out that since I was trying to connect to the third target displayed in the NAS GUI, I needed to use "--lun 2" (I figured they would all be LUN 0 since they all had unique target names).

BTW, if your targets happen to be on a Thecus NAS too, I found you can directly view the LUN numbers inside the file at /raid0/sys/ietd.conf on the Thecus NAS internal filesystem. This requires that you have installed the SSH module so you can ssh into the NAS. Also the zero in "raid0" might have to be replaced with another number if your NAS unit has multiple RAIDs setup.

So where ever your targets are hosted, you need to discover the LUN number of your target and specify it on the command line using the "--lun" option.

Once I got it working, I just left the disk attached to the SCSI controller, so I'm not sure if the SATA controller would work.

Hope that helps.

-Keith

ModEdit: The answer above is from the thread "iSCSI Problem".

[socratis]

Great, thanks for the feedback. Marking as [Solved].