Jeffrey L. Taylor writes: > > Will dd build a bootable disk? > > Yes, dd can build a bootable disk. It is just a bit for bit copy of the disk > partition, including the Master Boot Record (MBR). That is the point of using > complete copies of partitions, to do a bare metal restore. Restoring a > working, bootable system onto an empty hard drive.
Yes, if you dd the entire disk (i.e., from /dev/hda to /dev/hdb without specifying the partition(s)), it will copy everything including the boot block and all partitions within, unused space and all. > > Can that (dd'ed) clone be updated by rsync to make it current? Yes, if the filesystem is consistent. See below. > I find that dd for bare metal backups is dependable. Rsnapshot is fast > and convenient for incremental backups and restores. There are other > solutions that work. The downside of dd is that you must unmount all filesystems on the disk to be backed up before doing the copy. Since the dd session will take time to complete, if the filesystem is mounted and active, the time between the start and the end of the dd run, changes would have occurred and you'd end up with an inconsistent filesystem. This is because the superblock and inode table, etc., would become out of date and no longer fully reflect the state of the data blocks that gets eventually backed up. Depending on the amount of activity on the filesystem, the backup may become corrupt enough to be unusable. Also, on mission-critical systems, unmounting live filesystems for backup purposes may not be a feasible option. -Ti -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
