Date: Sat, 24 Mar 2001 08:51:07 -0700 From: "Justin T. Gibbs" <gibbs@scsiguy.com> To: Jeff Fellin <jkf@research.bell-labs.com> Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: SCSI-3 Message-ID: <200103241551.f2OFp7s26541@aslan.scsiguy.com> In-Reply-To: Your message of "Fri, 23 Mar 2001 17:59:07 EST." <200103232259.RAA03132@aura.research.bell-labs.com>
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>
>Folks,
>I'm trying to understand of the current CAM system supports
>SCSI-3 devices.
CAM talks to lots of SCSI-3 devices.
>I understand a LUN on a SCSI-3 device is 64 bits.
This depends on the topology you are talking about.
SPI - Lun is 6 bits unless you use packetized/infomation unit transfers
which gives you access to the full 64bit lun. There are
currently no devices on the market that support IUT.
FC - FC looks a lot like packetized parallel SCSI. I believe it
supports a 64bit lun.
>However, The type of lun_id_t only supports 32 bits. If
>FreeBSD really accesses SCSI-3 devices where is the conversion of
>32 bit cam_ccb entries to 64 bit LUN values on the SCSI bus occur?
We just don't fill in the top 4 bits on topologies that allow
such large lun identifiers. For SPI, you can't address that
high yet anyway.
>Also, is there any way to send a SCSI command with a 64 bit
>LUN on a SCSI bus
Not yet.
BTW, the work necessary to make the CAM layer fully SAM-2/SPI-4
compiliant is underway. I hope it will be completed for the 5.0
release.
--
Justin
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