[Gb-ccb] An external CCB USB connector?

[John Ford]

In reality this is how all network administration is done.  Boot to
single user mode, mount the filesystems read-only, enable the
networking, and dump the filesystem(s).  I suspect Wolfgang could tell
us how he would do this in a few sentences.

What we *really* need to be sure of is that we have a complete backup
of all the files that we modify from original, and not necessarily the
whole operating system.  We will most likely just replace the whole
box (CCB assembly) if a disk dies, and so we just need to be able to
make sure they all have identical software on them.

John

Martin Shepherd writes:
 > 
 > On Mon, 21 Nov 2005, John Ford wrote:
 > > I think the best solution for this is to figure out how to back it up over
 > > the network.  I don't want to modify the hardware, particularly the
 > > packaging, at this point.
 > 
 > Understood.
 > 
 > I'll take another look at network backups.  We could actually do this
 > right now, by simply using the dump command's options for remote
 > backups. However this is potentially risky, since it would involve
 > backing up an active root filesystem that might be written to during
 > the backup. This could lead to backing up partially written files,
 > inconsistencies in the filesystem superblock etc. I don't know how
 > significant this is, in practice, but there's nothing worse than a
 > broken backup, especially if the error is so subtle that it leads to
 > occasional unexplained strange crashes, long after the original
 > filesystem has been overwritten by a subsequent backup derived from
 > the first.
 > 
 > The recommended way to backup the root filesystem of a computer is to
 > boot into single-user mode, run the sync command to force all
 > unwritten data to disk, and then assume that the lack of running
 > networking and other daemons, means that nothing will be written to
 > the root filesystem while the backup is in progress. We, of course,
 > would need networking to be at least partially enabled, in order to
 > perform a network dump. So straight single-user mode wouldn't be
 > sufficient. However I'm guessing that entering single-user mode, from
 > the serial console, and then manually bringing up the network
 > interface, using the "/sbin/ifup eth0" command, without starting any
 > of the networking daemons, would be sufficient. One would need to
 > check whether the dump command, or the ssh command that it uses to
 > send and receive data, might write anything to log files during the
 > backup.
 > 
 > Martin
 > _______________________________________________
 > gb-ccb mailing list
 > gb-ccb at listmgr.cv.nrao.edu
 > http://listmgr.cv.nrao.edu/mailman/listinfo/gb-ccb