LT02 tape drive, how often recylce tapes

Basically I have the following schedule

JAN (odd month)
4 daily tapes used mon - thur
weekly tape on fridays
week 4 tape becomes monthly

FEB ( even month)
new set of daily tapes mon - thur
weekly tape on fridays
new week4 tape becomes monthly

MAR (odd month again, daily tapes brought back on site)

So the point is, the daily tapes get a lot of use

I am trying to figure out when its time to retire these tapes and buy new, seeing how 07 is starting...or do i just need to do a full format and be all set?

any ideas?
LVL 5
shankshankAsked:
Who is Participating?
 
dovidmichelCommented:
The typical thing to do is use them for a year and then rotate it out as a monthly and then a yearly tape.

Thing is these tapes are rated for around a million passes. Even if you figure that each time a tape is loaded that is one pass since the header is being read it still puts the theoretical life beyond the normal usage time.
0
 
andyalderCommented:
HP gives us 260 fills of the tape, IBM quote 300 somewhere, NetBackup sets the expiry to 300 full passes for LTOs (and 30 for DAT) but really you have to go by the soft error count on the media. Your backup software probably gives you the properties of the tape where you can see the hours in use and error count, divide the count by the hours to get an idea of the quality of the surface. A format doesn't recondition the surface but it generally resets the stats in the backup software database so you have less information available to you and think the tape is in better quality than it is.

Take this for example, but note it's referring to the ability of the media to retain the data for 30 years when stored properly and the storage temp/humidity requirements are far more tight than specified for use during the backup.

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?locale=en_US&taskId=120&prodSeriesId=34648&prodTypeId=12169&objectID=c00286108 

0
 
dovidmichelCommented:
I read it and am amazed HP would actually make such a statement that it is only good for 260 full backups. So does that mean I can backup to the same tape a million times as long as only 260 are full backups??? Every time a tape is loaded regardless of if the tape is written to or not that is typically about six passes of tape header. It adds up to six because there are several rewind and read commands issued.

Well if they want to say 260 that gives them a large safety zone and will sell more tapes. But then it is not unusual to find a big difference between what the drive and tape manufactures report.
0
 
andyalderCommented:
A million passes *is* about 260 full volume backups dovid, the tape passes the head hundreds of times to fill up the tape since it writes in serpentine pattern, I think they've factored in a bit of shoeshining and allowed for inventories since NBU gives 300, your own figure of a year = 365 isn't far off a million passes.
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.