Re: Photoscore

[David Kastrup]

David Wright <address@hidden> writes:

> On Tue 29 Nov 2016 at 09:37:21 (+0100), David Kastrup wrote:
>> David Wright <address@hidden> writes:
>> 
>> > On Mon 28 Nov 2016 at 21:26:17 (+0000), Karlin High wrote:
>> >> On 11/28/2016 2:12 PM, David Wright wrote:
>> >> > So it should be worth booting from a live linux CD to mount the
>> >> > partitions to check their contents, and to reinstall Grub
>> >> > (or whatever you use to boot) into the MBR.
>> >> 
>> >> The thing to do IMMEDIATELY is make a "drive image backup."
>> >
>> > That would certainly be the action to take if the drive was giving
>> > disk errors.
>> 
>> It's also the action to take if you are dealing with damage to the data
>> structures.
>
> That doesn't necessarily buy you any advantage in the case you
> outlined. There are risks in making bit for bit copies of a drive.
> For starters, you're _writing_ to a device, whereas attempting to
> mount the partitions readonly involves _no_ writing to any device.
>
> Only on the 18th, I read a post where a user was trying to make an
> image of a drive, and was relying on the order they plugged in the
> two drives to get the kernel to assign the "correct" /dev/sdX values
> to the two drives so that they could then follow some remotely
> posted instructions for making the copy. Talk about tail wagging dog!

Just as a P.S.: am in the mirroring stage now (my father acquired a new
somewhat larger SSD disk with some mSATA interface like his computer
uses internally (the kind of crap that exists these days...) and a
suitable USB adapter).

And indeed the externally attached drive (via USB) was named /dev/sda
while the internal drive the Linux rescue environment booted from was
/dev/sdb.  So this time round the root disk system not being able to
mount stuff on /dev/sda* had more than one reason.

But I was surprised that a USB-connected drive (even though connected at
bootup time) was listed before the internal mSATA one.  Without checking
via fdisk prior to starting the copy I would indeed have assumed the
reverse.

-- 
David Kastrup