gimili wrote: > On 7/12/11 2:31 AM, Andrew Ford wrote: >> My setup is somewhat simpler. My BackupPC datastore is stored on a >> 700GB LVM logical volume on a 1TB disk, and I have 3 external 1TB eSATA >> disks. Each week I make a snapshot of the BackupPC logical volume and >> "dd" the snapshot volume to one of the external disks (takes about 2 >> hours) and then "cmp" the snapshot volume and the raw partition on the >> external disk. The newest backup disk lives at home, I take the next >> oldest in to work and keep it in my desk, and bring the oldest disk >> home. >> >> Andrew >> > > Simple is good. I also use 3 external eSATA drives. I haven't tried > this yet but I was considering using a cron job to run the command > line command that generates a large tar file of the backup. I had a > complete hard disk failure 7 months ago and this was how I moved the > data from the backuppc machine to the new replacement drive on my > server. The only thing I would have to do is remember to cycle the > disks. > > Any comments on pros/cons to this method? > > Thank you, > Generating a tar file of the backup directory is going to walk the directory tree and read each of the files separately. Doing a "dd" of the snapshot volume is reading the disk sequentially (although there may be a certain amount of out-of-order data if there has been any activity on the underlying volume). Originally I was doing a recursive copy of the filesystem of the snapshot volume to the external disk, but that took much much longer than the block copy (I think it took something like 30 hours compared to 2). I suspect that making a tar file is going to take something in between the two extremes.
Andrew -- Andrew Ford South Wing Compton House Compton Green, Redmarley Gloucester, GL19 3JB, UK Telephone: +44 1531 829900 Mobile: +44 7785 258278 ------------------------------------------------------------------------------ Storage Efficiency Calculator This modeling tool is based on patent-pending intellectual property that has been used successfully in hundreds of IBM storage optimization engage- ments, worldwide. Store less, Store more with what you own, Move data to the right place. Try It Now! http://www.accelacomm.com/jaw/sfnl/114/51427378/ _______________________________________________ BackupPC-users mailing list [email protected] List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
