What is the recommended "maximum mounts"

[aftertheflesh]

Hi,

Does anyone know what Symantec or Quantum or Sony recommends for the "maximum mounts" setting in the media properties? We are running out of tapes quickly as many are hitting the current 500 max mounts as setup by a previous admin. We are not sure this is correct and are wondering if we are retiring tapes too earfly that could be used again after rewturning from 1 month offsite storage. Hardware info mis below.

NBU version 6.5.4  <----Ya, I know it's EOL

ADIC scalar i6000 w/ 12 Quantum LTO5 drives.

Tapes= Sony LTO5 LTX1500G  3TB (compressed) capacity

[revarooo]

Personally I would goto the vendor of the drives to find out what they recommend as the failure of the tapes would be hardware specific. They have 20,000 listed here for load/unload (so 1 operation would be 2 movements load then unload).

From Sony: http://www.tapeandmedia.com/sony_lto_5_tape_ultrium_5_tapes.asp

Sony LTO 5 Tapes (LTX1500G) LTO Ultrium 5 Tape Data Cartridge

With a compressed storage capacity of 3.0 TB, this new LTO Ultrium 5 cartridge delivers new functionality to support the ever-increasing requirements of today's data-rich storage environments. Users can now create two partitions within the cartridge, addressing both file control and space management. This feature can help to increase access speed, which is important for storing rich media files. The LTO-5 cartridge adds this feature while still retaining the hardware-based encryption introduced with LTO-4 technology, which helps to protect the storage and transport of sensitive information.

The new LT0-5 cartridge continues Sony's goal to develop environmentally responsible manufacturing processes. Sony's LTO cartridge shells are manufactured with recycled resin made from regenerated polycarbonate materials disposed by and collected from Sony group companies. This helps Sony reduce virgin resin usage by 95 tons per year.

• Up to 3.0TB Compressed Storage Capacity (2:1 compression)
• 280MB/Second Data Transfer Rate (compressed)
• 30 Years Estimated Archival Life
• 20,000 Load/Unload Cycle
• Limited Lifetime Warranty by Sony

from Quantum on LTO5 tapes.

http://www.quantum.com/serviceandsupport/softwareanddocumentationdownloads/lto-5/index.aspx

[mph999]

I will dig out another post I made on this. I summary, I did a lot of work on this question with in depth assistance from some of the real tape experts at Imation. By experts, I mean people who really really know about tapes and worked in the Imation lab in Germany doing things such as looking at tapes under microscopes to see why there was a failure. The summary we came to, was that the amount of mounts is effectivly meaningless as it is how the tape is treated during its life that is the over-riding factor. If you treated a tape 100% correctly, the number of mounts would be more relevant, however tapes are very rarely treated perfectly, so the other factors over-ride this. Martin

[mph999]

Here is the post: https://www-secure.symantec.com/connect/forums/media-information-1

[Nicolai]

You rock Martin.

I support Martin statement about the number of mount.

My progress to the subject is a little different.

According to the link below media reliability is 1 million passes. A LTO drive has 1280 track and warp the tape 20 times during full write so the tape is passed 1280/20 = 64 times for each full write.

We then divided 1 million / 64 = 15625 full writes before the 1 million passes is reached.

However the world is never perfect. I then turn the the match around. My minimum retention time i 1 month so in 4 years the tape will be passed 48 times * 64 = 3072 times. I then  assumes we "shoe-shine" and multiply this value 4 and we get 12280 passes in 4 years. Still loooong way from 1 million. However as Martin pointed out - the environmental conditions has a great impact. And does the drive nothing else than "shoe-shine" you will get bad tapes and drives.

http://www.tapeandmedia.com/hp_lto_5_tape_ultrium_5_tapes.asp

[mph999]

Thanks Nicolai, that is another excellent way to look at it ....