[comp.unix.i386] Exabyte 2.2 Gb Streamer for ISC

pda@rsiatl.UUCP (Paul D. Anderson) (07/31/90)

I have been looking into getting an Exabyte 2.2 Gig streamer for
my system and one other.  (Disk drives are getting cheap and
it's getting tough to back them up on 60Mb DC600A cartridges!)

I'm running ISC 2.2 on a 16 bit bus with 20 Mhz/386/8 Mb main
memory.  Disk controller is Adaptec 1542 talking to a Newbury
4380S (300 meg scsi) and a Maxtor 8760S (650 meg scsi).  That's
basic hardware config.

Has anyone been using an Exabyte (or related drive)?  How fast is
it?  Does it require special utilities or will tar or cpio
drive it with No Problem through a specific device (and what device
is that?)  HELP!

Thanks!
-paul

-- 
* Paul Anderson * Crossroads Computing * (404) 565-0761 * emory!rsiatl!pda * 
              "SCCS: The condom of promiscuous programmers"

root@maxed (0000-Admin(0000)) (08/01/90)

In article <3417@rsiatl.UUCP> pda@rsiatl.UUCP (Paul D. Anderson) writes:
>I have been looking into getting an Exabyte 2.2 Gig streamer for
>my system and one other.  (Disk drives are getting cheap and
>it's getting tough to back them up on 60Mb DC600A cartridges!)
>
>I'm running ISC 2.2 on a 16 bit bus with 20 Mhz/386/8 Mb main
>memory.  Disk controller is Adaptec 1542 talking to a Newbury
>4380S (300 meg scsi) and a Maxtor 8760S (650 meg scsi).  That's
>basic hardware config.
>
>Has anyone been using an Exabyte (or related drive)?  How fast is
>it?  Does it require special utilities or will tar or cpio
>drive it with No Problem through a specific device (and what device
>is that?)  HELP!

The Exabyte SCSI tape device does work with ISC 2.2--thru the normal
tape device file: /dev/tape  with a major number of 41, minor 8--
but it's very very picky as to block size.  For writes we
can't get good consistent results using pax or tar or cpio directly,
we have to use find ... -cpio, next best is cpio with a 1k block size,
and for reads nothing works consistently except cpio with a big
buffer, say 256k.  Otherwise we get all kinds of error messages,
including tape not loaded, end tape press any key, error on read...

A better option if u want to spring for the extra $$ is the Chantal
drivers which not only work any which way you want to write to the
Exabyte, but come with nice utilities for displaying addresses
and ROM versions of installed devices as well as retension, rewind,
reset, erase...These drivers work with the fast file system, but
replace the HPDD--they are a little faster, and support worm. opto-
magnetic and other drives.


-- 
 Ed Whittemore 		uunet!maxed!ed    ed@maxed.amg.com
 American Micro Group, Inc. 		201 944 3293

karl@naitc.uucp (Karl Denninger) (08/01/90)

In article <3417@rsiatl.UUCP> pda@rsiatl.UUCP (Paul D. Anderson) writes:
>I have been looking into getting an Exabyte 2.2 Gig streamer for
>my system and one other.  (Disk drives are getting cheap and
>it's getting tough to back them up on 60Mb DC600A cartridges!)
>
>I'm running ISC 2.2 on a 16 bit bus with 20 Mhz/386/8 Mb main
>memory.  Disk controller is Adaptec 1542 talking to a Newbury
>4380S (300 meg scsi) and a Maxtor 8760S (650 meg scsi).  That's
>basic hardware config.
>
>Has anyone been using an Exabyte (or related drive)?  How fast is
>it?  Does it require special utilities or will tar or cpio
>drive it with No Problem through a specific device (and what device
>is that?)  HELP!

Well, if you build for SCSI tape on the 1542, it works great.  I backup
about 6 systems every night to it over Ethernet.  Peak speeds reach
10MB/minute.

--
Karl Denninger	AC Nielsen
kdenning@ksun.naitc.com
(708) 317-3285

guest@sherpa.UUCP (Guest Account) (08/07/90)

In article <1990Aug01.125704.4279@maxed>, root@maxed (0000-Admin(0000)) writes:
>Has anyone been using an Exabyte (or related drive)?  How fast is
>it?  Does it require special utilities or will tar or cpio
>drive it with No Problem through a specific device (and what device
>is that?)  HELP!

I installed a 2.2G tape drive and a 720M hard drive in a system about 6 months
ago.  The hard drive works great!!!  The tape drive STINKS!  Sorry to be so
harsh, but the tape drive needs turned on and off 2 to 4 times per week!  This
makes it very unreliable for unattended backups.  Now, the company that we
purchased the tape drive from is NOT Exabyte, but I will bet money that it is
the same drive.  Features and looks are what I base this on.  The place where
we bought the drive from says that there is a known static problem with the
drive, in other words, it is overly sensitive to static.

The Exabyte drive might be fine, but just ask around about any unusual static
problems with it, just to be sure.  I hate to see people get burned!

Speed wise it seems fine, no real numbers to throw out, but compared to the
60M we have, it is very fast.

Yes, you can use tar and any other Unix commands that access the tape drive.

If anyone wishes to response, please do so to "...!uunet!sherpa!bmhalh!bruce".

Bruce

jcm@pegasus.ATT.COM (John Mcmillan) (08/08/90)

In article <303@sherpa.UUCP> guest@sherpa.UUCP (Guest Account) writes:
>In article <1990Aug01.125704.4279@maxed>, root@maxed (0000-Admin(0000)) writes:
>>Has anyone been using an Exabyte (or related drive)?  How fast is
>>it?  Does it require special utilities or will tar or cpio
>>drive it with No Problem through a specific device (and what device
>>is that?)  HELP!
>
>I installed a 2.2G tape drive and a 720M hard drive in a system about 6 months
>ago.  The hard drive works great!!!  The tape drive STINKS!  Sorry to be so
>harsh, but the tape drive needs turned on and off 2 to 4 times per week!  This
>makes it very unreliable for unattended backups.  Now, the company that we
>purchased the tape drive from is NOT Exabyte, but I will bet money that it is
>the same drive.  Features and looks are what I base this on.  The place where
>we bought the drive from says that there is a known static problem with the
>drive, in other words, it is overly sensitive to static.
>
>The Exabyte drive might be fine, but just ask around about any unusual static
>problems with it, just to be sure.  I hate to see people get burned!
:

For 7 months I've been working with 3 3B2's SHARING 2 Differential SCSI busses,
and having an additional Single-Ended SCSI bus per machine.  This included two
Exabyte [Feith Systems packaged] tapes, an [almost unused]AT&T 9-track, and
7 disk controllers on the Diff' bus.  (Additionally, there was one Disk
controller and one Cartridge-tape contrller on each internal S-E SCSI.)

These tapes ran about 15 hours/day, but saw only about two tapes per day.
Typical throughput:
	find ... -print | cpio -oacC 32768 > ...    yielded about 300 MB/hr.
Much of our time was spent on remote, RFS'd File-systems at only about
120 MB/hr... not the tape's fault.  (Even the 300 MB/hr is presumably
below the tape's capabilities.)

Initially, Exabytes were on the Diff' SCSI and we had aggravatingly
frequent problems.  Turning the Exabyte drives off and on was a frequent
requirement -- once to a dozen times a week.  Service calls on them was
frequent -- about every month there was a call on one or the other
drive.  We've shipped drives for remote-service with cassettes
still in them because NOTHING would release the tapes!

Concerned about problems during booting and problems in which the
SCSI busses seemed to hang because of tape problems, we converted the
tapes to S-E SCSI and hung them off the internal busses.  Since then,
we've had fewer service calls and only replaced one.  Our inexplicable,
hair pulling reboot problems have about disappeared -- but... we've
made other improvements too, including isolating the almost unused 9-track.
But most significantly, we've stopped locking up the shared Diff' busses.

Exabyte's have been an unpleasant experience... but we've ordered another one
because where else can you get the volume of backup?  [Yeah... we thought
a lot about a stack of DAT's.  Have DAT's developed any track record yet?]


john mcmillan -- jcm@pegasus.att.com -- muttering for SELF ONLY, not AT&T

richard@pegasus.com (Richard Foulk) (08/11/90)

>I installed a 2.2G tape drive and a 720M hard drive in a system about 6 months
>ago.  The hard drive works great!!!  The tape drive STINKS!  Sorry to be so
>harsh, but the tape drive needs turned on and off 2 to 4 times per week!  This

Exabyte's has a reputation for being fairly reliable.  I suspect you got
a bad one, or more likely a bad vendor/driver.

If I could afford an Exabyte I'd own one myself.  I've seen a lot of
feedback about Exabytes on the net, (mostly in comp.sys.sun) and the
majority of it has been favorable.


-- 
Richard Foulk		richard@pegasus.com

pim@cti-software.nl (Pim Zandbergen) (08/24/90)

karl@naitc.uucp (Karl Denninger) writes:

>In article <3417@rsiatl.UUCP> pda@rsiatl.UUCP (Paul D. Anderson) writes:

>>Has anyone been using an Exabyte (or related drive)?  How fast is
>>it?  Does it require special utilities or will tar or cpio
>>drive it with No Problem through a specific device (and what device
>>is that?)  HELP!

>Well, if you build for SCSI tape on the 1542, it works great.  I backup
>about 6 systems every night to it over Ethernet.  Peak speeds reach
>10MB/minute.

I've got two related questions:

1) How do 8mm video tape streamers compare to DAT streamers
   (like Wangtek's) in regard of their price, reliability,
   and tape price. Which system will become "standard" ?

2) We will still need to use our Archive VIPER SCSI tape unit.
   This will mean having two tape units on the 1542.
   tape(7) says:
	 Bits 4-7 (the high order nibble of the minor number)
	 indicate the drive number.
   This means it should be possible to mknod say /dev/tape2,
   but I will be very interested to hear if anyone actually
   tried this.

Thanks in advance.

PS. The original article(s) were posted with 'Distribution: na'
    so don't try to find them if you don't live in North America.
-- 
Pim Zandbergen                            domain : pim@cti-software.nl
CTI Software BV                           uucp   : uunet!mcsun!hp4nl!ctisbv!pim
Laan Copes van Cattenburch 70             phone  : +31 70 3542302
2585 GD The Hague, The Netherlands        fax    : +31 70 3512837