jt34@prism.gatech.EDU (THOMPSON,JOHN C) (06/14/91)
Do the Adaptec controllers and drivers for Unix support scsi 2 command queing
and tagged commands? If one connects a scsi 2 device to one of these will it
be automatically recognized and run in the scsi 2 mode or does one have to
do something special? How about scsi 2 fast mode 10MB/sec - is this supported?
Finally does Adaptec have a 32 bit EISA or MCA controller yet? Thanks.
--
THOMPSON,JOHN C
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!jt34
Internet: jt34@prism.gatech.eduneese@adaptx1.UUCP (06/16/91)
>/* ---------- "Adaptec SCSI 2 Support" ---------- */ >Do the Adaptec controllers and drivers for Unix support scsi 2 command queing >and tagged commands? If one connects a scsi 2 device to one of these will it >be automatically recognized and run in the scsi 2 mode or does one have to >do something special? How about scsi 2 fast mode 10MB/sec - is this supported? >Finally does Adaptec have a 32 bit EISA or MCA controller yet? Thanks. The AHA-1740 EISA adapter, when in enhanced mode, has support for tag queuing. The recently released ASW-1450 SCO UNIX driver supports tag queuing as well, as long as the SCSI device supports tag queuing. The 1740, in enhanced mode, will also run 10MB/sec, if the device will support it. The 1542B/1640 (MCA) adapters do not support tag queuing, or 10MB/sec sync transfers. All of the adapters, regardless of mode, support on board command queuing. There is no electrical difference between SCSI-1 and SCSI-2. There are only added features/enhancements to SCSI-2. Only when running faster than 5MB/sec sync are there any timing differences, but that has to be negotiated for by both target and initiator. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese
jt34@prism.gatech.EDU (THOMPSON,JOHN C) (06/19/91)
In your message you state that the 1740 HBA supports tagged commands in enhanced
mode. Do the 1740 UNIX drivers support this enhanced mode currently? Is this
the 1540 ASW software you mention? Specifically what version of the drivers
offer this support ver ###? Under UNIX is their a programmers interface to send
scsi commands directly to a device - is this the software you wrote which is
often mentioned on the net? How does one obtain these programs - does it come
with the HBA?
We are in the process of developing a scsi based disk array. The actual drives
need only be scsi 1 but the array controller which sits between the drives
and the HBA is scsi 2. This array controller supports both fast mode (10MB/sec)
and tagged commands. The tagged command support is especially important since
in a multiuser environment you would like to have as many of the individual
drives working simultaneously on seperate requests so as to maximize overall
system throughput. As you can tell from my questions a big stumbling block
has been finding the HBA/device driver combinations to support this effort.
My experience thus far has shown that most manufacturers are just beginning
to address scsi 2 issues (and rightfully so). Even the disk array
manufacturers in existence today are only just beginning to understand the
implications of scsi 2 tagged commands and how it affects array performance.
Do SUN, DEC, HP, etc. support tagged commands yet on their workstations?
If anyone has experience with disk arrays either user or developers I would
welcome any input you might have. Please post or email me direct. Thanks.
--
THOMPSON,JOHN C
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!jt34
Internet: jt34@prism.gatech.eduneese@adaptx1.UUCP (06/20/91)
>/* ---------- "Re: Adaptec SCSI 2 Support" ---------- */ >In your message you state that the 1740 HBA supports tagged commands in enhanced >mode. Do the 1740 UNIX drivers support this enhanced mode currently? Is this >the 1540 ASW software you mention? Specifically what version of the drivers >offer this support ver ###? Under UNIX is their a programmers interface to send >scsi commands directly to a device - is this the software you wrote which is >often mentioned on the net? How does one obtain these programs - does it come >with the HBA? >STUFF DELETED< All 1740 enhanced mode drivers we are involved with contain support for tag queuing. The problem you will have is finding a drive that properly supports tag queuing. I believe HP has 1 and Imprimis/Seagate has one. These are the only tag queuing drives I have seen and know to work. The 1540 does not support tag queuing. As far as an interface in any UNIX driver to allow a utility to pass commands to the hardware. This is best addressed to the UNIX folks (SCO, ISC,..). If they have such a beast, it would be implemented differently between them. The software I have written is simple utilities for doing things with SCSI devices most folks can't get at. All of my stuff is available from many places, but from me, either by Email or anon uucp. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese
feustel@netcom.COM (David Feustel) (06/23/91)
Is your stuff available via anonymous FTP as well? FTP is a lot easier for me. Thanks. -- David Feustel, 1930 Curdes Ave, Fort Wayne, IN 46805, (219) 482-9631 EMAIL: feustel@netcom.com or feustel@cvax.ipfw.indiana.edu I voted for Bush once. As it's turning out, once was once too often.