Forum Discussion

AB_Panthro's avatar
AB_Panthro
Level 4
12 years ago

Is verify required these days?

I'm backing up several VM's to a dedupe store on a Qnap NAS box and am getting around 2GB/min throughput.  The backup jobs themselves are pretty quick, but the verify takes just as long again.

Do we really need verify any more now most companies are using things like HDD's and dedupe?

2012
Backing Up
Backup and Recovery
Backup Exec
  • VJware's avatar
    VJware
    12 years ago

    Verbatim ~ explanation of verify operation -

    During a verify job operation, Backup Exec reads the data stream and  re-calculates the check sums and compares it with what is written in the media.
     
    Backup Exec does not compare the files on the tape or backup to disk folder with the files on the hard disk. Instead, it performs a Cyclic Redundancy Check (CRC) verification of the data on the backup media. A CRC performs a mathematical calculation on a stream of data and returns a number that represents the content and organization of that data and uniquely identifies this data stream. This CRC verification ensures the data was stored correctly and can be re-read.
    This applies ir-respective of backing up to tape or disk.

5 Replies

Sort By
  • pkh's avatar
    pkh
    Moderator
    12 years ago

    It is always recommended that you do a verify to ensure your backup is a good one.  Otherwise, you might only discover that it is bad when it is time for a crucial restore.

  • AB_Panthro's avatar
    AB_Panthro
    Level 4
    12 years ago

    Well, that's what the PC Support handbook says...

    I've been involved in DR for probably 15yrs now and verifying on tape jobs on particular was essential as it was such a sensitive technology.  Later tape technology like LTO carried out their own verification of the data as it wrote, so even then verify on the backup job was becoming superfluous.

    I'd like to know if there's anything inherent in how BE2012 does backups to HDD and Dedupe that might make turning verify off less of a risk.  For example the dedupe process is pretty complex and I suspect there will be data verification during that.

  • VJware's avatar
    VJware
    Level 6
    12 years ago

    Verbatim ~ explanation of verify operation -

    During a verify job operation, Backup Exec reads the data stream and  re-calculates the check sums and compares it with what is written in the media.
     
    Backup Exec does not compare the files on the tape or backup to disk folder with the files on the hard disk. Instead, it performs a Cyclic Redundancy Check (CRC) verification of the data on the backup media. A CRC performs a mathematical calculation on a stream of data and returns a number that represents the content and organization of that data and uniquely identifies this data stream. This CRC verification ensures the data was stored correctly and can be re-read.
    This applies ir-respective of backing up to tape or disk.
  • pkh's avatar
    pkh
    Moderator
    12 years ago

    I doubt you are going to get an answer to your question.  It is up to you to judge the risk vs. the cost of doing verifies.

  • AB_Panthro's avatar
    AB_Panthro
    Level 4
    12 years ago

    So it looks like the verify and BE's own CRC are still very separate processes.  What I may do is disable verify and introduce a weekly backup readability test.

    Thanks for the input!