Starting out in iSCSI - recovery questions / options from target vanishing...

[Karl Pielorz]

--On 18 January 2010 13:13 +0200 Daniel Braniss <danny at cs.huji.ac.il> wrote:

> Hi karl,
> 	what version of iscsi_initiator are you using?
> if it's not 2.2.x then get it from:
> 	ftp://ftp.cs.huji.ac.il/users/danny/freebsd/iscsi-2.2.3.tar.gz

Hi,

Thanks for the reply :)

It's whatever version was in 7.2-STABLE as of around June (looking at that, 
I need to update lol - csup now running).

Having messed around with it for some time now - I've found:

 - Setting it up works, and it actually 'works' so long as everything is 
accessible.

 - If the remote target dies - it does in fact appear to reconnect at what 
seems 30 second intervals (and, given time [sometimes minutes] will 
recover, if the target is available 'as it was' before)

 - If you cannot get the original target back, your pretty much doomed. The 
device on the FreeBSD side (e.g. da0) will hang on any I/O, and it never 
seems to give up.

You can't stop iscontrol, nor kill it - nor can I find any way of telling 
the system to just 'give up' and lose the data. After varying amounts of 
time the system slowly grinds to a halt (probably as other processes get 
stacked up on the vacant da0 device), and you have to reboot the system.

Attempting to kld_unload the iscsi_initiator module leads to a far faster 
reboot (typically a panic).

Would the 2.2.3 files above change any of this? - Is there meant to be a 
'clean break' or something you can do to forcibly detach missing iscsi 
targets from the system (so recover it) - losing any data not written? - 
preferably without rebooting the whole server?

-Karl