For various reasons, when I installed our server, I configured it so that it would boot off a USB flash disk. The flash disk mounts as /boot and / mounts on our RAID array.

It all works very well, but I would like to have backup so that if/when the flash disk goes, I can pop in another one.

I have tried to make copies of the flash disk (using both cp and dd), but it doesn't work. When the server starts its bootup sequence, instead of Linux loading, a cursor starts blinking endlessly.

If I put the original flash in, it works fine. If I put the copy in, it doesn't work.

I can't see any difference between the copy and the original. They seem to have the same content. If I do blkid both have the same label and UUID. The label is /boot, and /etc/fstab refers to this

We are running Scientific Linux 5.4.

Any ideas gratefully received.

Thanks,

Scott

how?
seems no mbr. use dd if=/dev/sda of=/dev/sdb bs=512 count=1

1 members found this post helpful.

how?
seems no mbr. use dd if=/dev/sda of=/dev/sdb bs=512 count=1

Many thanks --- that's solved it and saved me much trouble. I had done dd if=/dev/sda1 /dev/sdb1, which explains.