# /dev/sdb1 is not a valid block device - [SOLVED]

## peaceful

I used dd to clone my SATA drive in /dev/sda to an identical drive in /dev/sdb.  sda is a completely configured gentoo system.

When I try to mount the partitions from sdb I keep getting "/dev/sdb1 is not a valid block device".

What gives?  fdisk can see it just fine.

```
# mount /dev/sdb1 /mnt/backup

mount: /dev/sdb1 is not a valid block device

# ls -l /dev/sdb1

brw-rw----  1 root disk 8, 17 Sep  5 15:33 /dev/sdb1

# fdisk /dev/sdb

The number of cylinders for this disk is set to 19457.

There is nothing wrong with that, but this is larger than 1024,

and could in certain setups cause problems with:

1) software that runs at boot time (e.g., old versions of LILO)

2) booting and partitioning software from other OSs

   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): p

Disk /dev/sdb: 160.0 GB, 160041885696 bytes

255 heads, 63 sectors/track, 19457 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1   *           1           9       72261   83  Linux

/dev/sdb2              10         134     1004062+  82  Linux swap / Solaris

/dev/sdb3             135       19457   155211997+  83  Linux

```

----------

## peaceful

Opening up /dev/sdb with fdisk and then performing a write ('w') seems to have fixed it.

Apparently dd'ing an entire hard drive isn't quite enough to set up the partitions.

----------

