heiser@tdw201.ed.ray.com (03/02/90)
As I understand it, the 8mm helical-scan cartridges are not recommended for multiple-usages. Do any of you in net-land have any experience in this area? Do you re-use your "expired" 8mm backup tapes? If so, have you noticed a problem with high error-rates? How many times do you re-use the cartridges? Thanks in advance for sharing your experiences with these units. Bill Heiser | Work: heiser@tdw201.ed.ray.com | {decuac,necntc,uunet}!rayssd!tdw201!heiser | Home: Bill.Heiser@f240.n322.z1.fidonet.org (Fidonet 1:322/240) | The Think_Tank BBS (508) 655-3848 | Other: 75106.2332@compuserve.com
richard@sunkist.west.sun.com (Richard Seegmiller) (03/06/90)
#As I understand it, the 8mm helical-scan cartridges are not recommended #for multiple-usages. Do any of you in net-land have any experience in #this area? Do you re-use your "expired" 8mm backup tapes? If so, have #you noticed a problem with high error-rates? How many times do you re-use #the cartridges? I am using an Exabyte backup system on our 3/260 running 4.0.3. The drive is installed off a SCSI-3 host adapter. I use Sun's device driver supplied w/ 4.0.3 for the Exabyte. I also use an mdump (multiple dump on one tape) facility supplied through APUNIX. I have been cycling tapes now for the past 1.5 years. This is our backup schedule level 0: every day. keep each day's backup for one week keep each week's backup for 3 months after three months, keep one backup for each month forever Consequently I have MANY tapes that have been used as many a 15-20 times. I have had to do restores from these tapes and have had NO problems at all. On this system I have had two (2) backups fail, and both of them were media failures. The first failure was about 1 month after we started using the Exabyte (it was a new Sony tape), the second failure was about one month ago ( it was a reused Sony tape, used about 10 times). I don't have any statistics on the error rates on the backups on used tapes. Yet my experience has been that we have had no failures recovering data from our backup tapes. My recommendation would be to reuse the tapes. Richard Seegmiller Research & Techonology Development De La Rue Printrak 1250 N. Tustin Ave. Anaheim, CA 92807 Phone: (714)666-2700 Internet: sol!richard@sunkist.West.Sun.COM sol!richard%sunkist.West@Sun.COM (for hosts table hosts) UUCP: ...!sun!sunkist!sol!richard
tonyr@tekig5.pen.tek.com (Tony Rick) (03/07/90)
In article <5506@brazos.Rice.edu> sol!richard@sunkist.west.sun.com (Richard Seegmiller) writes: >X-Sun-Spots-Digest: Volume 9, Issue 71, message 5 > >#As I understand it, the 8mm helical-scan cartridges are not recommended >#for multiple-usages. Do any of you in net-land have any experience in >#this area? Do you re-use your "expired" 8mm backup tapes? If so, have >#you noticed a problem with high error-rates? How many times do you re-use >#the cartridges? > >I am using an Exabyte backup system on our 3/260 running 4.0.3. ... > ... I have been cycling tapes now for the past 1.5 years. ... > > ... Consequently I have MANY tapes that have been used as many a 15-20 times. > ... On this system I have had two (2) backups fail, and both of them >were media failures. ... > > ... Yet my experience has been that we have had no failures recovering >data from our backup tapes. My recommendation would be to reuse the >tapes. I agree with Richard's recommendation. We have a 4/370 with a third party Exabyte on the SCSI bus, using SUN's SCSI driver (st). We have only been doing backups for 6 months, and have re-used some tapes three times. The only failures were with new, unused tapes (two instances out of ~100 tapes). We use Sony P6-120MP tapes. I called Exabyte. The person there told me that the tapes they supply are SONY, are good (guaranteed?) for 10 years, even under re-use. I do not know if the tapes Exabyte supplies are the same ones I get. Does anyone out there know? I have had no restore failures. When I saw the original posting I wrote a small routine that simply reads the whole tape, expecting that media failures would be reported, and chose some multiple use tapes at random to check. There were no failures reported. Re-use 'em, I say. Tony Rick tonyr@tekadg.adg.tek.com Tektronix, Inc. Beaverton, OR.
richard@sunkist.west.sun.com (Richard Seegmiller) (03/08/90)
Tony Rick <tonyr@tekig5.pen.tek.com> asks:
#We use Sony P6-120MP tapes. I called Exabyte. The person there
#told me that the tapes they supply are SONY, are good (guaranteed?) for 10
#years, even under re-use. I do not know if the tapes Exabyte supplies are
#the same ones I get. Does anyone out there know?
I talked to Steve Small at Exabyte about 1 year ago regarding 'certified'
vs 'non-certified' media. His response is as follows:
1. Certified tape means:
- tapes are sampled by Exabyte in a batch random basis
- Tapes guarenteed 100%
(my note: at $25-$30 / tape they can afford to be guarenteed 100%)
2. Available media suppliers are:
- Sony: Exabyte uses Sony. They are the only ones that meet
reliability requirements.
- TDK
- Fuji
- Maxell
Note: If Kodak wants tape & buys from TDK, typically Kodak label
will be higher quality media than TDK label.
I buy Sony 120 minute tapes from any low cost supplier. I figure at $6
/tape we can insure/guarentee the tapes ourselves. If I were ever to have
a media failure on restore, too bad, I lost some data (and a tape). I
can't retrieve the data, and neither can Exabyte, so the most Exabyte can
do for me is to replace the tape. I can do that for $6, ... BIG DEAL!!!
Richard Seegmiller
Research & Techonology Development
De La Rue Printrak
1250 N. Tustin Ave.
Anaheim, CA 92807
Phone: (714)666-2700
Internet: sol!richard@sunkist.West.Sun.COM
sol!richard%sunkist.West@Sun.COM (for hosts table hosts)
UUCP: ...!sun!sunkist!sol!richard