24 Mar
2005
24 Mar
'05
6:20 a.m.
Quick check to see if anyone's ever tried this. (where "tried" =
"written some code to do so")
In theory one could hook up a system running linux/*bsd with a SCSI
controller present acting as a target rather than initiator, and have
the machine pretend to be a tape drive, hard disk etc.
I have no idea if the linux / *bsd kernels (or card drivers) support
running as a target, or if the necessary hooks are present into user-
land (eg. via 'sg') to allow user code to do the emulation, though.
Just thought I'd ask if anyone's attempted to do it before...
(personally I can write sg device code, but I'm by no means a kernel
hacker)
cheers
J.
24 Mar
24 Mar
6:36 a.m.
On Thu, 2005-03-24 14:20:40 +0000, Jules Richardson <julesrichardsonuk at
yahoo.co.uk>
wrote in message <1111674040.2356.34.camel at weka.localdomain>:
I have no idea if the linux / *bsd kernels (or card
drivers) support
running as a target, or if the necessary hooks are present into user-
land (eg. via 'sg') to allow user code to do the emulation, though.
Linux doesn't feature target mode SCSI, but at some time, there were
at least some patches available for at least some controllers. Some
folks tried to do IP-over-SCSI.
I'm not sure, but I seem to recall that at least one of today's BSDs
ships along with target mode. IIRC it's even used in some embedded
storage systems.
MfG, JBG
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6:57 a.m.
>>>> "Jules" == Jules Richardson
<julesrichardsonuk at yahoo.co.uk> writes:
Jules> Quick check to see if anyone's ever tried this. (where "tried"
Jules> = "written some code to do so")
Jules> In theory one could hook up a system running linux/*bsd with a
Jules> SCSI controller present acting as a target rather than
Jules> initiator, and have the machine pretend to be a tape drive,
Jules> hard disk etc.
Jules> I have no idea if the linux / *bsd kernels (or card drivers)
Jules> support running as a target, or if the necessary hooks are
Jules> present into user- land (eg. via 'sg') to allow user code to
Jules> do the emulation, though.
I've heard of targets for iSCSI, which of course is just SCSI over a
different type of cable. Since a lot of OS (including Linux) support
iSCSI initiators, if you need SCSI emulation without weird hardware
hacking, an iSCSI target may be a good way to go.
I don't have pointers to specific examples handy.
paul
9:28 a.m.
Jules Richardson wrote:
In theory one could hook up a system running linux/*bsd with a SCSI
controller present acting as a target rather than initiator, and have
the machine pretend to be a tape drive, hard disk etc.
I have no idea if the linux / *bsd kernels (or card drivers) support
running as a target, or if the necessary hooks are present into user-
land (eg. via 'sg') to allow user code to do the emulation, though.
I have *really* wanted to do this to emulate disks for some odd scsi
machines I have (disk which have nonstandard block sizes - don't ask).
I looked really hard and found some things close, but not quite. No
actual code, however.
There was some talk about doing in the linux world. I have not found
anything working, however. I did find a commercial product but I think
it was tape oriented.
Ideally I'd like a linux kernel module which worked with a common scsi
card. I'd be most happy if the module/driver would allow me to write
the actual target code in userland.
Please let me/us know if you find anything. I know it can be done but
don't have the time to write a driver.
I could swear I did see some hacks to a qlogic card which came close.
-brad
7:10 p.m.
I have *really* wanted to do this to emulate disks for
some odd scsi
machines I have (disk which have nonstandard block sizes - don't ask).
It looks like Fujitsu did some work for Linux a couple of years ago.
Other sources claim Linux lacks the target-mode middle layer.
FreeBSD is supposed to be able to do this, however.
De
7213
days inactive
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4 comments
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participants (5)
-
brad＠heeltoe.com -
drb＠msu.edu -
jbglaw＠lug-owl.de -
julesrichardsonuk＠yahoo.co.uk -
pkoning＠equallogic.com