Re: need sd card backup on r-pi-3b
On Saturday 23 September 2017 10:58:47 Gene Heskett wrote:
> On Saturday 23 September 2017 07:43:14 Jonathan Wilson wrote:
> > On Fri, 2017-09-22 at 22:07 -0400, Gene Heskett wrote:
> > > Greetings;
> > >
> > > Trying to dd a copy of the micro-sd card the pi-3b is booting
> > > from, to another micro-sd card in a usb reader/writer, and winding
> > > up with nothing but an empty lost+found directory on it.
> > >
> > > Obviously some sort of a syntax error, but it still takes the pi
> > > several hours to do it, with the traffic led on the reader/writer
> > > showing continuous activity.
> > >
> > > Is there another way/util that actually works for making verbatim
> > > backups of these limited lifetime sd cards?
> > >
> > > Thanks.
> > >
> > > Cheers, Gene Heskett
> >
> > I used to use dd quite a lot, usually to a file (from a disk) as I
> > was playling with virtual boxes quite a bit. It "may" be that the dd
> > is not from the disk, but is from a partition... or some other
> > variation on the theme (1). Also, its worth typing sync after the dd
> > to make sure that all disk access (write) is coalesced. If I recall
> > correctly, once the sync returns to the command line then there are
> > no more pending writes so even pulling the SD (not correctly
> > un-mounting/ejecting it) shouldn't corrupt it.
>
> All followed and understood.
>
> > (1) When dd'ing between physical drives I always made sure they were
> > matched size wise, which was probably not required but I had it in
> > my head that dd'ing a drive including the partition table to a
> > larger sized drive would cause issues. Where the drives were
> > unmatched I'd set the new partition(s) manually, and then dd the
> > partitions one at a time and I always made sure the too partition
> > was set up to be the same size as the from partition (even if the
> > location differed) and then do any re-sizing of the cloned partition
> > & file system upwards afterwards. As I say, possibly not required in
> > some/all cases but gut feelings are hard to overcome as I had it in
> > my head - something to do with backup tables set at the far end of
> > partitions.
>
> humm... backup inodes are generally at 8k offsets from the starters
> location, or so I've read.
>
> And why, when I click on reply to list, do I get blank to: lines and
> have to manually copy them from the incoming email? Its a right pita.
My problem, I didn't have folder marked as containing a mailing list.
Fixed, sorry for the noise.
> Cheers, Gene Heskett
Cheers, Gene Heskett
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