HD to SSD question.

[Gregory Hosler]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 08/21/2013 11:15 PM, ergodic wrote:
> Caveat.
> 
> The UUIDs of the newly partitioned drive will most probably be different
> from those of the original drive which can create problems with the booting
> and swap partitions. Check the /etc/fstab file to see what UUIDs the OS is
> using.

agreed. I forgot to mention the UUID problem. In the migration scheme I
discribed, I use either Labels (which I will deliberately make the same) or LV
(which won't change, or if it will, I update fstab accordingly.

> The UUIDs of the original drive and partitions should be identical to those
> of the cloned drive. When a whole drive is cloned all at once the UUIDs are
> the same.
> 
> The following commands can be used to check the UUID:
> 
> $ ls -l /dev/disk/by-uuid/ or: $ blkid /dev/sdxy (where x = drive, y =
> partition, eg. /dev/sda1) or: sudo blkid
> 
> To assign a given UUID to a drive/partition use the command tune2fs eg.
> 
> sudo tune2fs /dev/sdb4 -U f0acce91-a416-474c-8a8c-43f3ed3768f9
> 
> This command will change the UUID of /dev/sdb4 to
> "f0acce91-a416-474c-8a8c-43f3ed3768f9"
> 
> Also try the command dcfldd it is an improved dd.
> 
> 
> 
> 
> 
> ----- Original Message ----- On 08/19/2013 04:57 AM, Erik P. Olsen wrote:
>> I plan to swap the HD on my laptop with an SSD of same size. Will it
>> work OK if I dd the HD to an external HD, swap the HD with the SSD and dd
>> the contents back to the SSD? I believe I can use knoppix to the
>> process.
> 
> 
> it would be safer to create your partitions, and then dd them (the
> partitions) one by one from one place to the other (or use backup storage
> in between).
> 
> examples:
> 
> dd if=/dev/sda1 of=/dev/sdb1 bs=1024000
> 
> with backup storage (in this case a file -- probably very large)
> 
> dd if=/dev/sda1 of=/junk/sda1 bs=1024000 dd if=/junk/sda1 of=/dev/sdb1
> bs=1024000
> 
> Thinks to keep in mind:
> 
> large bs will make the copy faster. multiples of 1024 are good in that the 
> layout on the disk (at the block layer) will be 1024.
> 
> the destination partition needs to be same size or larger. This will NOT
> work if the destination is smaller. In that case resize the source
> partition to be the same size or smaller before the dd. If you DO need to
> do this, then you will need to compute bs= / size= so that they match (or
> slightly exceed) the filesystem size, since the dd would (by default) copy
> the entire partition.
> 
> Once the copy is complete do a resizefs on it to expand the filesize to
> the new partition size.
> 
> Note that the swap partition should just be recreated (mkswap) instead of 
> copied. This is especially true if the new swap partition is a different
> size.
> 
> This method can also be used to copy file systems from a partition to an lv
> (a "logical" partition, if you will) or vice versa.
> 
> ===
> 
> I use this method all the time whenever I am migrating to a new (larger)
> disk with larger partitions.
> 
> I create the new partition table (with same or larger sized partitions)
> and then I dd from the old to the new (placing the new disk in an external
> usb casing).
> 
> Swap disks, boot into a rescue disk, re-write my mbr, and i'm done.
> 
> one last thing...
> 
> The source partition should be unmounted. If a mounted partition is being 
> copied, then the result (destination) is that mounted partition. As boot
> time, it will need to be fsck. Any open files will be in whatever state
> they were in when they were copied. Hence, all files should be closed.
> 
> When I do the above mentioned migration, I boot into single user mode and
> then do my dd. no services running, no user space stuff editing/creating
> files, etc.
> 
> Been doing this for years.
> 
> All the best,
> 
> -Greg
> 
> 
> 

- -- 
+---------------------------------------------------------------------+

Please also check the log file at "/dev/null" for additional information.
                (from /var/log/Xorg.setup.log)

| Greg Hosler                                   ghosler at redhat.com    |
+---------------------------------------------------------------------+
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.14 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

iEYEARECAAYFAlIU3qoACgkQ404fl/0CV/Rl5ACg0D09emWrZMqSzg9aaUbpqMpe
S6IAnAu156UtP4NnH5g1FjcpW0mDx5jc
=Dtki
-----END PGP SIGNATURE-----