How much data is transfered during backup? RRS feed

  • Question

  • How much data is transfered between the server and client to check what files have been updated?
    I know this is not supported but I have installed Hamachi on the server and clients off site, and everything is working as it should. However, as some locations have 8/1 MBit/s ADSL I do notice problem with the backup times taking many hours even if there's almost no changes made to the client since last backup.

    My guess is that there is a lot of data transfered to compare the files. Is there any way to reduce the amount of data? (I have already excluded download folders etc from backup to reduce the amount of data)

    I do know that this is due to my connections speed. In other words, those of you with greater connection speed should be able to back up remote clients with no problem at all.

    Monday, November 29, 2010 8:01 AM

All replies

  • Remote backups are going to take a long time if they're actually going to be useful at the end of the day. Hours is probably about right (days if it were an initial backup). The only way to reduce this significantly is to back up so little data that you would be unable to use the backup for a bare metal restore.

    And also bear in mind that remote restore is, in general, impossible. You would need a second computer in the remote location that's also connected to your server, and (at least) several days to restore a failed hard drive.

    I'm not on the WHS team, I just post a lot. :)
    Monday, November 29, 2010 11:08 AM
  • Thanks Ken

    I'm aware about the remote restore issues, if that happens I will either bring the server with me or get the client computer back to my place. What I can't understand how so much data has to be transfered to back up only a few files which was changed within the last 12 hours. I ran a manual backup 12 hours before this automatic backup started, and backing up this laptop now is still only at 85 % after running for approx 11 hours, almost maxing the 8 MBps available. Even on 8 MBps, a lot of data can be transfered during 11 hurs.

    I'm not sure exactly how the backup compares the files to check if anything is changed, but I do believe something is wrong if this much is being transfered.

    Monday, November 29, 2010 12:28 PM
  • For sure checksums for clusters in use (to determine if they've changed) etc. Also certainly, the Windows Home Server Drivers For Restore folder gets sent every time. Maybe some NTFS metafiles. It all adds up to a few GB of data. At home, that all transfers back and forth in a few minutes, but from afar it takes hours.

    I'm not on the WHS team, I just post a lot. :)
    Monday, November 29, 2010 2:04 PM