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tvmo's avatar
tvmo
Level 3
14 years ago

How many LTO tapes?

How can I calculate how many tapes I need? Does compression cloud the calculation or should I base calc on un compressed?

I'm going to be vaulting so does this make a difference to leaving tapes in the library?

How can I efficiently utilise tapes when vaulting?

Thanks

7.1.x and Earlier
Backup and Recovery
Basics
Best Practice
NetBackup
Tip-How to
  • Andy_Welburn's avatar
    Andy_Welburn
    14 years ago

    the following is from the NetBackup 6.5 Backup Planning and Performance Tuning Guide

    "...

    Calculate how many tapes are needed to store and retrieve your backups.
    The number of tapes depends on the following:
    ■ The amount of data that you back up
    ■ The frequency of your backups
    ■ The planned retention periods
    ■ The capacity of the media that is used to store your backups.

    If you expect your site's workload to increase over time, you can ease the pain of future upgrades by planning for expansion. Design your initial backup architecture so it can evolve to support more clients and servers. Invest in the faster, higher-capacity components that can serve your needs beyond the present.

    A formula for calculating your tape needs is shown here:

    Number of tapes = (Amount of data to back up) / (Tape capacity)

    To calculate how many tapes are needed based on all your requirements, the
    previous formula can be expanded to the following:

    Number of tapes = ((Amount of data to back up) * (Frequency of backups) * (Retention period)) / (Tape capacity)

    ..."

    It demonstrates this further with an example based upon using compressed or uncompressed tape capacity.

    Also, the type of data that is involved may well have a bearing on this depending on its compressibility.

    Can't really comment about Vault as have had no exposure to it.

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  • Andy_Welburn's avatar
    Andy_Welburn
    Level 6
    14 years ago

    the following is from the NetBackup 6.5 Backup Planning and Performance Tuning Guide

    "...

    Calculate how many tapes are needed to store and retrieve your backups.
    The number of tapes depends on the following:
    ■ The amount of data that you back up
    ■ The frequency of your backups
    ■ The planned retention periods
    ■ The capacity of the media that is used to store your backups.

    If you expect your site's workload to increase over time, you can ease the pain of future upgrades by planning for expansion. Design your initial backup architecture so it can evolve to support more clients and servers. Invest in the faster, higher-capacity components that can serve your needs beyond the present.

    A formula for calculating your tape needs is shown here:

    Number of tapes = (Amount of data to back up) / (Tape capacity)

    To calculate how many tapes are needed based on all your requirements, the
    previous formula can be expanded to the following:

    Number of tapes = ((Amount of data to back up) * (Frequency of backups) * (Retention period)) / (Tape capacity)

    ..."

    It demonstrates this further with an example based upon using compressed or uncompressed tape capacity.

    Also, the type of data that is involved may well have a bearing on this depending on its compressibility.

    Can't really comment about Vault as have had no exposure to it.

  • tvmo's avatar
    tvmo
    Level 3
    14 years ago

    I like you Andy, that's a second greta answer you've given to my posts. smiley

  • Deepak_W's avatar
    Deepak_W
    Level 6
    14 years ago

    Thanks andy... This post is really helpful for all the community members,

     

    my vote for you... yes

     

    tvmo - close this thread if query is resolve