|
Jason,
The CmdSN window allows the target to control the resources
consumed
by commands. I don't understand the need to save "all PDU
header
comes from the Initiator until corresponding statSN is
explicitly
ACKed". What purpose is that accomplishing (e.g., why save
all
the iSCSI Data-Out PDU headers for a SCSI
WRITE)?
In any case, the original PDU header is required for a Reject in
order
for the initiator to figure out what was rejected. If
the initiator
cannot figure that out, it is going to have a very difficult
time
recovering from the Reject.
Thanks,
--David
----------------------------------------------------
David
L. Black, Distinguished Engineer
EMC Corporation, 176 South St., Hopkinton,
MA 01748
+1 (508)
293-7953
FAX: +1 (508)
293-7786
black_david@xxxxxxx
Mobile: +1 (978)
394-7754
----------------------------------------------------
Hi David,
Thank you for the suggestion. A little more
to consider is that it seems that whatever mechanisms we use, as a target, we
must reserve all PDU header comes from Initiator until the coressponding
statSN is explicitly acked. For a resource-limted iscsi target engine(all
SCSI data is on host, so it is not in this question), It can be considered as
a big memory consumer and becomes a bottlenack.
Best
Regards,
Jason
From: Black_David@xxxxxxx
Subject: RE: Send Reject PDU when orignal
to-be-rejected PDU is notavailable
Date: Tue, 15 Apr 2008 23:04:15
-0400
To: hzj_wuying@xxxxxxxxxxx; ips@xxxxxxxx
The original PDU header has to be sent back so
that the initiator
knows what was rejected. iSCSI has a number
of mechanisms that
can be used by the target to control resource
consumption and
those should be used
to ensure that adequate resources are
available to deal with the
PDU that is to be rejected.
Thanks,
--David
----------------------------------------------------
David L.
Black, Distinguished Engineer
EMC Corporation, 176 South St., Hopkinton,
MA 01748
+1 (508)
293-7953
FAX: +1 (508)
293-7786
black_david@xxxxxxx
Mobile: +1 (978)
394-7754
----------------------------------------------------
Dears,
I am curently implement
iscsi target on a resource-limted device. In my implementation, orignal
to-be-rejected PDU is not available when it realised that a Reject
should be sent to initiator.
But as RFC3720 said, Target
must send back the orignal PDU as the Reject's payload.
So my question is: Why we need to send back the
orignal PDU ? Can we simply eliminate
it?
Thanks!
Best Regards,
Jason
“七件武器，七种完美” 立刻体验！
Windows Live Writer，支持离线撰写博客内容，随时随地想写就写。 立即使用！
|
