used dd to clone linux install

infinity42 · 07-06-2005, 11:17 AM

I have 2 IDE harddrives connected at the moment:
hdd - 60Gb Seagate - Currently holds my entire FC3 linux install (inc. home, etc..)
hdc - 80Gb Hitachi DeskStar - New, Blank

What I want to do is to put the complete linux from hdd onto the blank hdc, then remove hdd, and boot from hdc. (There are several reasons for it, it's just a stopgap measure, I will soon be wiping and installing Gentoo

)

So what I did was this

Code:

 $dd if=/dev/hdd of=/dev/hdc bs=64M

I then used fdisk to verify the partition table, and created a new partion with the unused space (because i dd'ed 60Gb onto an 80Gb drive). Then I installed Grub onto hdc.

All seemed fine. Booted fine etc., but when I logged in I started noticing lots of little things:
XMMS had changed back to it's default skin, but my playlist was still there as I had left it. It started claiming that it had no mp3 support (in the FC3 base install mp3 is not installed, but I have installed it) and yet, would play mp3s. Then I fired up firefox, and home had reverted to file:///usr/share/doc/HTML/index.html, which is the default after a fresh install. But all my bookmarks were still there. Also worker fails to start because

Code:

 Cannot create temporary directory /tmp/thomas-tmp.1627eaf/files/worker-thomas: Read-only file system

Most things were still fine, Bluefish, GKrellM, xfce.. all were exactly how I left them.

I still have the 'original' copy on hdd, and won't be wiping it until I'm sure I haven't lost anything.

I'm just getting a bad feeling about it..
Is this a Bad Sign?
Have I done something wrong?
Might I have lost some data?

Any thoughts/random mumblings/rants etc. welcome

whizbit · 07-06-2005, 11:29 AM

wwhat does the 64m mean

infinity42 · 07-06-2005, 11:34 AM

The 64M means dd in blocks of 64Mb; so read 64Mb, then write that 64Mb, then read 64Mb, then write that 64Mb... and so on.

I think I may have just found the problem: It would seem that my root partition is mounted Read-Only. mtab clearly says

Code:

 /dev/hdc2 / ext3 rw 0 0

but whenever I try to write anything it fails with 'read only filesystem', even root can't touch anything. Will try remounting root.

FinalFantasy · 07-06-2005, 11:42 AM

why not use tar instead of dd?

two harddrive with different sizes, dd is not a good choice, IMO.

infinity42 · 07-06-2005, 11:46 AM

I have just tried to remount my root partition, but it refuses:

Code:

# mount -t ext3 /dev/hdc2 / -o remount,rw
mount: block device /dev/hdc2 is write-protected, mounting read-only

However, my boot partition (hdc1) is mounted rw, and I can remount it fine.

Code:

# ll /dev/hdc*
brw-rw----  1 root disk 22, 0 Jul  6 17:13 /dev/hdc
brw-rw----  1 root disk 22, 1 Jul  6 17:13 /dev/hdc1
brw-rw----  1 root disk 22, 2 Jul  6 17:13 /dev/hdc2
brw-rw----  1 root disk 22, 3 Jul  6 17:13 /dev/hdc3
brw-rw----  1 root disk 22, 4 Jul  6 17:13 /dev/hdc4

They have the same permissions, so why does hdc2 refuse to mount rw?

Any help/suggestions would be greatly appreciated.

infinity42 · 07-06-2005, 11:47 AM

Sorry about that FinalFantasy, you must have pasted as I was replying. Yes, I didn't think dd was ideal.. but I didn't think of tar. I will have a look, thanks for the tip.

FinalFantasy · 07-06-2005, 12:12 PM

did you have rw in the grub config file?

such as

kernel /...... rw root=.....

infinity42 · 07-06-2005, 01:53 PM

No, they are all 'kernel ... ro ...' This has always worked fine when root=hdd2. Doesn't this just mean that the initrd initially mounts the root readonly, and then it is remounted read-write later on in the boot? That's what seems to happen in the boot proccess anyway. I would give rw a go, but I ran fsck on hdc2, and it found quite a few biggies, enough to make it drop out and request that I do it manually. I guess this means that the dd went wrong at some point, so I will wipe it and try a different method. (I have now booted back to hdd). Might dump all my data onto my 200Gb SATA drive (Just got to decide between Reiser3 and ext3 for it.. hmm..) & then install FC2 (Someone has nicked off with my FC3 DVD grrr) over the old FC3, just to get a working system for a few days, then I can get gentoo on it.

Moral of the story: Don't use dd to do silly things

Thanks for all the help, I'll post back if I get it all worked out.