We are currently using DLT IV tapes, SDLT tapes, and LTO3 tapes for our backups. Since the DLT and SDLT tapes are getting pretty old, I was wondering when these tapes should be retired and replaced with new tapes? Some of ours are over two years old. We rotate them every two weeks and reuse them every 7th week. I'm not sure of how many times they have been written to, but wanted to know if anyone knows as a rule of thumb how long these tapes should be "kept around"? Thanks in advance for your help!
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When to retire backup tape media?
- Thread starter cthrash
- Start date
Very good question, one I have been researching for a long time.
You could go on age, though the life of a LTO tape (for eg) is years, depending on how it is used. If you straem to an LTO (so writing >25ish MB/s) it will last years probably, providig it's not dropped, mis-handeled etc ...
If you don't get the data out quick enough, the drives will stop/start - known as shoeshining, this could wreak a tape in as little as 5 mounts, or it might not - it's unknown.
Some drives, such as storagetek, are designed to stop/start so this is not an issue.
YOu could count the no. mounts as a rough guide to tape useage (as the header is read so at least part of the tape has passed the heads on the dive, if you check the tape manufactures page, they will give figures such as max no mounts, no of full tape passes etc ..., so wrost case is each mount = 1 full tape pass, hence if no mounts=max no of tape passes then retire.
Not that simple though, re. section above on stop/start.
Generally, if tapes are rotated, age is not really an issue, as the shelf life is many years, depending on how they are stored (temp/humidity etc ...).
So, you could go on actually backup failures and errors (bit late by then I know), biut these can be difficult to work out as it could be the media or the drive.
So in answer to your question, there is no scientific way to work out your answer (sorry), without some specialist software.
(before anyone asks, I don't work for them) ...
Hi_stor make a product called storsentry (marketed through Imation). This software monitors tapes and drives at a low level (bit level) and using a combination of errors off the drive, clever functions and stats) predicts tape and drive failure, before you get errors.
Does it work - yep, I'm trialing it for my company and have visited a reference site to really see it in action, and it is the Daddy, so to speak.
Also, don't waste time researching other software, it is unique, no other company has yet come up with anything close.
Martin
You could go on age, though the life of a LTO tape (for eg) is years, depending on how it is used. If you straem to an LTO (so writing >25ish MB/s) it will last years probably, providig it's not dropped, mis-handeled etc ...
If you don't get the data out quick enough, the drives will stop/start - known as shoeshining, this could wreak a tape in as little as 5 mounts, or it might not - it's unknown.
Some drives, such as storagetek, are designed to stop/start so this is not an issue.
YOu could count the no. mounts as a rough guide to tape useage (as the header is read so at least part of the tape has passed the heads on the dive, if you check the tape manufactures page, they will give figures such as max no mounts, no of full tape passes etc ..., so wrost case is each mount = 1 full tape pass, hence if no mounts=max no of tape passes then retire.
Not that simple though, re. section above on stop/start.
Generally, if tapes are rotated, age is not really an issue, as the shelf life is many years, depending on how they are stored (temp/humidity etc ...).
So, you could go on actually backup failures and errors (bit late by then I know), biut these can be difficult to work out as it could be the media or the drive.
So in answer to your question, there is no scientific way to work out your answer (sorry), without some specialist software.
(before anyone asks, I don't work for them) ...
Hi_stor make a product called storsentry (marketed through Imation). This software monitors tapes and drives at a low level (bit level) and using a combination of errors off the drive, clever functions and stats) predicts tape and drive failure, before you get errors.
Does it work - yep, I'm trialing it for my company and have visited a reference site to really see it in action, and it is the Daddy, so to speak.
Also, don't waste time researching other software, it is unique, no other company has yet come up with anything close.
Martin
Networker volume manager maintains some usefull counters which can help you:
mminfo -q pool=MYPOOL -r volume,mounts,recycled,olabel
This command will give you the number of times the read-label function was performed, the number of times the volume was relabeled and the first time the volume was labeled (=the age of the media if the volume was not used before).
If a volume is "too old" (more than 5 years?) AND "many times" (more 50 times?) relabeled, then replace it. (You have to adjust criteria to fit to your configuration).
mminfo -q pool=MYPOOL -r volume,mounts,recycled,olabel
This command will give you the number of times the read-label function was performed, the number of times the volume was relabeled and the first time the volume was labeled (=the age of the media if the volume was not used before).
If a volume is "too old" (more than 5 years?) AND "many times" (more 50 times?) relabeled, then replace it. (You have to adjust criteria to fit to your configuration).
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