Rescue a crashed computer
Uit DeVliegendeWiki
Here are some experiences with rescueing a crashed computer
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Access Computer through Ubuntu Live CD & Gnome
Once in a while, I have a laptop where I cannot easily take out the harddisk for backing up. It would be cool if I could boot from a Linux CD (e.g., Ubuntu Live CD), access the HD + some backup media, and backup the harddisk.
So far, I have never had good experiences with live CD's. They seem to take forever to boot,if they boot at all. Recently, I succeeded with the following procedure:
- Just get as far as possible with the live CD
- Press ALT-1 (or was it ALT-F1?) to get somehow to a console
- Type startx, and tada... Where in Gnome! The root password is empty in these cases.
The alternative would be to do everything from the console, but so far, I didn't feel like having to mount devices. When using Gnome, this seems to be taken care of already.
Conclusions
Again, live CD's don't seem to work for me: it kept loading from the CD like forever. Let's try a shell
Access Computer through Ubuntu Live CD & Shell
Here's the procedure:
- Start with the Ubuntu live CD untit it starts complaining about something
- Use ALT-F1 to get to a console.
Mount the harddisk
This specific computer has one harddisk, which seems to be partitioned in three (or more?) parts:
ls /dev/h* /dev/hda /dev/hda1 /dev/hda2 /dev/hda3 /dev/hda5 /dev/hdc /dev/hpet
I issued:
sudo mount /dev/hda1 /media/win1
and after this, I could read the partition like through
ls /media/win1
However, this doesn't seem the partition I'm looking for. Let's try again:
sudo mkdir /media/win2 sudo mount /dev/hda2 /media/win2
Tjakka! It worked. Apparently, without an endless string of obscure switches. Maybe this HD somehow wasn't formatted with NTFS or so.
However,
sudo mkdir /media/win3 sudo mount /dev/hda3 /media/win3
gave error:
mount: you must specify the filesystem type
So I am afraid it's time to get more into mount:
More about mounting this hda3
Let's start with the mount --help:
Usage: mount -V : print version
mount -h : print this help
mount : list mounted filesystems
mount -l : idem, including volume labels
So far the informational part. Next the mounting.
The command is `mount [-t fstype] something somewhere'.
Details found in /etc/fstab may be omitted.
mount -a [-t|-O] ... : mount all stuff from /etc/fstab
mount device : mount device at the known place
mount directory : mount known device here
mount -t type dev dir : ordinary mount command
Note that one does not really mount a device, one mounts
a filesystem (of the given type) found on the device.
One can also mount an already visible directory tree elsewhere:
mount --bind olddir newdir
or move a subtree:
mount --move olddir newdir
One can change the type of mount containing the directory dir:
mount --make-shared dir
mount --make-slave dir
mount --make-private dir
mount --make-unbindable dir
One can change the type of all the mounts in a mount subtree
containing the directory dir:
mount --make-rshared dir
mount --make-rslave dir
mount --make-rprivate dir
mount --make-runbindable dir
A device can be given by name, say /dev/hda1 or /dev/cdrom,
or by label, using -L label or by uuid, using -U uuid .
Other options: [-nfFrsvw] [-o options] [-p passwdfd].
For many more details, say man 8 mount .
This doesn't help too much. Actually, http://www.techonthenet.com/linux/mount.php suggested to try:
sudo mount /dev/hda3 /media/win3 -t ntfs
which resulted in:
Failed to mount '/dev/hda3': Invalid argument The device '/dev/hda3' doesn't have a valid NTFS. Maybe you selected the wrong device? Or the whole disk instead of a partition (e.g. /dev/hda, not /dev/hda1)? Or the other way around?
I give up here.
Mount USB stick
I could identify what devices are related to my USB stick by inserting and ejecting the stick several times:
/dev/usbdev4.3_ep00 /dev/usbdev4.3_ep01 /dev/usbdev4.3_ep81.
Actually, when I insert it, the shell says something that seems to identify the device as sda. However, when issueing:
sudo mount /dev/usbdev4.4_ep00 /media/usb1
I get the error:
/dev/usbdev4.4_ep00 is not a block device
BTW: The numer after usbdev seems to increase constantly.
Anyhow, this avenue doesn't seem to go nowhere. Let's try to mount that mysterious sda device:
sudo mount /dev/sda /media/usb1
which gave an error about an unknown file system. On a windows computer I checked, and the file system was FAT.
sudo /mount /dev/sda /media/usb1 -t fat
gave an error that fat is an unknown option, and that maybe i ment vfat. Whatever:
sudo /mount /dev/sda /media/usb1 -t vfat
didn't result in anything more sensible.
Ah, http://www.cyberciti.biz/tips/linux-how-to-use-usb-penflash-stick.html suggests that USB-devices are treated like SCSI-devices (that's funny: Windows NT used a similar SCSI-simulation for ATA harddisks). That's where the obscure sda device opped up when inserting the USB stick.
The solution
sudo mount /dev/sda1 /media/usb1
Again, the trick is to mount the partition sda1, rather than trying to mount sda itself.
Access computer with Bootable CD
I have a bootable CD, that boots into some DOS-like environment. Questions are (1) Can it read the hard disk, which probably is formatted as NTFS? (2) Can it access a device like a USB stick?
