state of iscsi_initiator?

Danny Braniss danny at cs.huji.ac.il
Wed Oct 1 05:35:55 UTC 2008


> 
> I'm just playing with iSCSI now, on a fresh 7.1-STABLE machine connected 
> to another FreeBSD box running ports/net/iscsi-target.
> 
> I am using the latest version 2.1 Initiator from:
> ftp://ftp.cs.huji.ac.il/users/danny/freebsd/
> 
> It seems alot better now than when I last tried it.  The speed is 
> constant at around 50MB/s for a single sequential read or write.  It 
> also reconnected very quickly when I restarted the target.  I was even 
> able to reboot the target box and I/O resumed perfectly once it finished 
> booting!
> 
> The speed increased to 80mb/s when I ran two threads, which is close to 
> the max performance for the network cards in this machine.
> 
> 
> A couple of minor issues:
> 
>     1. Trouble shutting down iscontrol - after I kill -9 it stays around 
> for a minute or more until it finally goes away.
> 

you should kill -1, this does an orderly shutdown of the connection.
I guess an update to the manual is needed.

>     2. Under very heavy multi-threaded load, the client machine gets 
> sluggish to respond, even to keystrokes on the console.  And if I 
> shutdown the target, even local disk accesses on the client computer 
> stop working after a while.
> 
>     (I don't think this is a problem with iSCSI initiator.  I suspect 
> there's something in FreeBSD which pauses all disk I/O if the length of 
> outstanding requests is too high, can anyone shed some light on this?)
> 
I've noticed slugishness when a heavy fsck is running in the background - not
iscsi related, so it seems that heavy disk IO is using up resources, but
then again, the CPU is working :-)

> 
> Overall, a pleasant experience and shows how much good work has been 
> done on iSCSI.  Congratulations Danny :-)
> 
thanks,
	danny




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