[ipxe-devel] SAN error

Robin Smidsrød robin at smidsrod.no
Thu Nov 22 12:16:19 UTC 2012

On 16.11.2012 13:44, Mircea Iordan wrote:
> I have a QNAP storage and I try  3  weeks to boot fom iscsi without
> success. It say “Could not open SAN device: Input/output error
> (http://ipxe.org/1d0d6139)”

This is basically an error message that the iSCSI target is unavailable,
as pointed at by the source code at

> I read on your page that is some file to change in sources (iscsi.c) to
> work with QNAP discussed in http://forum.qnap.com/viewtopic.php?p=100984.

Can you post this patch by TangoMan mentioned in
http://forum.qnap.com/viewtopic.php?p=100984#p101750 to this mailinglist
so we can see what it does?

> I used lastest ipxe.iso iPXE 1.0.0+ (d6b0).
> Is anyone willing to build ipxe.iso for me with necessary changes to be
> compatible with QNAP? (I'm not a linux handy)

You can download a default build of ipxe.iso from this url:


It includes the required features to boot iSCSI volumes.

If you're still having problems you've should verify that you have
configured your iSCSI target (server) properly. I'd suggest you look
carefully into access control settings. Those are the most commonly wrong.

CC Michael: This is the response from a QNAP developer (David Tsao)
about the problem: "From the logs that customer sent to us last time, we
could observe that initiator didn't response target proposed
keys "MaxConnection" and "ImmediateData" and make the connection attempt
failure. These two keys are declared as negotiation keys and should be
responded by the negotiation party.

We also found some non RFC compliant initiators (such as globalSAN) will
not response keys, such as "MaxBurstLength",
"FirstBurstLength", "DefaultTime2Wait", and "DefaultTime2Retain". And to
make our targets more "friendly", we have forced the target to use the
default key value when these initiator didn't response those to us.
To solve the gPXE issue, either our target change the negotiation
behavior for these two mentioned keys or change the initiator."

-- Robin

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