Disaster with DD overwiting some of / partition

[Andrew_OC]

Hi,

For reasons best left unexplained the following has happened

OS Mandriva 2006 Xmas Club Edition

system setup as follows :

[root@server1 ~]# df
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 780M 332M 409M 45% /
/dev/sda8 33G 212M 32G 1% /home
/dev/md0 151G 103G 48G 69% /home/raid
/dev/sda9 981M 17M 915M 2% /tmp
/dev/sda6 5.8G 2.0G 3.6G 36% /usr
/dev/sda7 33G 507M 31G 2% /var

sda = SATA O/S Drive
md0 = 2 disk RAID 1 setup

attached a usb compact flash adapter and forgot this system already used the sda for it's os so the USB would be on sdb NOT SDA

ran the following

[root@server1 ~]# dd if=./mira_netrixm_2007JAN11.img of=/dev/sda
250368+0 records in
250368+0 records out

thought "that was too quick, did it work?", ran it again (!)

[root@server1 ~]# dd if=./mira_netrixm_2007JAN11.img of=/dev/sda
dd: reading `./mira_netrixm_2007JAN11.img': Input/output error
116832+0 records in
116832+0 records out

Panic set in...


now if I do ls / I get no files shown, however if I go ls /etc/ the files appear OK.

Samba still works and can read files
Users can also still login via ssh
Can cat /etc/samba/smb.conf
can cat /boot/grub/menu.lst.example
can ls /proc


I *think* that just some of the root partition has been slightly overwritten, so is there any possibility that the mandriva install disk could repair this or am I down to putting a fresh disk in and setting the system up again ?

[devils casper]

hi Andrew_DC !

Partition Table is overwritten. you can restore it. dont shutdown your machine coz it will be a bit problematic then.
download TestDisk and recover partitions. if image file is too big, it will be difficult to recover all data. check this thread,






Casper

[Andrew_OC]

using testdisk I've more info


Disk /dev/sda - 79 GB / 74 GiB - CHS 9726 255 63
Partition Start End Size in sectors
* Linux 0 1 1 100 254 63 1622502
L Linux Swap 101 1 1 303 254 63 3261132
L Linux 304 1 1 1067 254 63 12273597
L Linux 1068 1 1 5335 254 63 68565357
L Linux 5336 1 1 9598 254 63 68485032
L Linux 9599 1 1 9725 254 63 2040192

looks like I've over written the first partition only (which is the boot partition ?)

the / fs seams to be in the 3rd partition down

can I recover the boot partiton ?

[devils casper]

i think its not possible to recover data.
first of all recover partition table. shutdown system. system wont boot up from Harddisk coz of missing Boot Loader. boot up from LiveCD and check whats missing.
its easy to re-install Boot Loader and re-write missing files in /boot partition. if your / (root) partition is intact then you are safe.





Casper