Bus and tag! I thought that you had progressed beyond the 1980's. Actually, we jut got rid of our last B/T devices a couple of months ago. However, we referred to them as bug and tag - they, not the cables or interface to the computer, were problem devices. Their replacements are about the only ESCON devices we have left. Maybe the vendor will upgrade to Ficon in about 20 years.
Regards, Richard Schuh > -----Original Message----- > From: The IBM z/VM Operating System > [mailto:ib...@listserv.uark.edu] On Behalf Of Tom Duerbusch > Sent: Monday, June 01, 2009 1:09 PM > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: Z/VM and 3590 tape speed > > Actually, it's the opposite. > > FICON is the only way to drive an IBM 3590 drive. > ESCON is way, way too slow. > > I have ESCON attached B11 (9 MB/s transfer rate). I get > about 4 MB/s when controller hardware compression is used. I > get about 6 MB/s when compression is turned off. > > They are about twice as fast as my bus and tag 3480 drives. > > Tom Duerbusch > THD Consulting > > >>> "Hughes, Jim" <jim.hug...@doit.nh.gov> 6/1/2009 1:55 PM >>> > I am looking at table 3 on page 10 of the 3590 Introduction > and Planning Guide. > > It mentions two things of interest: > Device Data Rate(native) and Data Transfer Rate(maximum > instantaneous). > > Device Data Rate for the E11 is 14 MB/Sec. > Data Transfer Rate depends on the channel. > > I guess what I am reading says the tape will move around at > 14 meg/sec no matter how fast I get the data to the device. > FICON for tapes is a waste of time. > > When would FICON for tapes be a good idea? > > > ____________________ > Jim Hughes > 603-271-5586 > "It is fun to do the impossible." > > ==>-----Original Message----- > ==>From: The IBM z/VM Operating System > [mailto:ib...@listserv.uark.edu] On ==>Behalf Of Tom Duerbusch > ==>Sent: Monday, June 01, 2009 2:46 PM > ==>To: IBMVM@LISTSERV.UARK.EDU > ==>Subject: Re: Z/VM and 3590 tape speed ==> ==>You're > getting confused between tape drive speed and channel speed. > ==> > ==>The IBM 3590 E and H drives will read/write to the tape at > a rate of > 14 > ==>MBs. Multiple that rate by your compression rate, if you > have ==>compression turned on. > ==> > ==>The FICON channel, can operate at 200 MB or 270 MBs (on a z/890). > ==> > ==>So if you had 2:1 compression, you would see a transfer of 28 MBs. > ==>Uncompressed it will be 14 MBs at best. > ==> > ==>And that is what you are seeing. > ==> > ==>These are data streaming drives. You have to feed the > beast. If your ==>source (disk) can't keep up with the tape > drive and it's compression, you ==>will see much, much lower > transfer numbers. > ==> > ==>Tom Duerbusch > ==>THD Consulting > ==> > ==>>>> "Hughes, Jim" <jim.hug...@doit.nh.gov> 6/1/2009 1:08 > PM >>> ==>We have Z/VM 5.4, with 4 3590's attached to the > z890 using FICON Express ==>with the 2-Gbps feature. The tape > controller is the A60. > ==> > ==> > ==> > ==>I am doing some tape speed tests and my results are not > very good. I ==>have a pipeline(look below) that writes > 65,500 byte blocks to the 3590. > ==>I used the cms command TAPE MODESET ( NOCOMP/COMP to turn > compression ==>off/on. > ==> > ==> > ==> > ==>I see around 14 MB/sec with compression off and 28 MB/sec > with ==>compression on. > ==> > ==> > ==> > ==>The 3590 Planning manual says the 3590's should operate at > 200MB/sec ==>when using FICON with the 2-Gbps feature. > ==> > ==> > ==> > ==>There maybe a problem with my pipeline or my expectations. > ==> > ==> > ==> > ==>Here is the pipeline. Any insight or suggestions are welcome. > ==> > ==> > ==> > ==>/* */ > ==> > ==>arg blkcnt . > ==> > ==>if blkcnt = "" then exit 99 > ==> > ==> > ==> > ==>numeric digits 12 > ==> > ==> > ==> > ==>"TAPE REW" > ==> > ==>"TAPE FSF" > ==> > ==>say time() > ==> > ==>x = time("E") > ==> > ==> > ==> > ==>"PIPE literal <------------> | >> tapetest 3590 a" > ==> > ==> > ==> > ==>"PIPE (endchar ?) ", > ==> > ==> "? xrange 00-ff |", /* 256 characters*/ > ==> > ==> " dup 256 |", > ==> > ==> " specs todclock 1 1-* n |", > ==> > ==> " join 256 |", /* 64k */ > ==> > ==> " dup * |", > ==> > ==> " specs todclock 1 1-* n |", > ==> > ==> " fblock 65500 00 |", > ==> > ==> " take " blkcnt " |", > ==> > ==> " cnt: count lines |", > ==> > ==> " tape 181 |", > ==> > ==> " specs 1-1 1 |", > ==> > ==> " join 4999 |", > ==> > ==> " specs todclock 1 |", > ==> > ==> " dateconv 1.8 todabs ISODATE timeout |", > ==> > ==> " specs recno 1 ", > ==> > ==> " substring fs . f 1 of word 2 nw ", > ==> > ==> " /5,000 Blocks Interval Check/ nw |", > ==> > ==> " console |", > ==> > ==> " >> tapetest 3590 a ", > ==> > ==> "? cnt: | var xblkcnt | specs / Blocks written =/ 1 w 1 > nw |", ==> ==> " console" > ==> > ==> > ==> > ==>____________________ > ==> > ==>Jim Hughes > ==> > ==>603-271-5586 > ==> > ==>"It is fun to do the impossible." > ==> > ==> >
