DeviceImage Tools

[wolfgangbeyer]

Hi!

What can be the reason for the following error message when I start unzsplit:

inflating laptop_0.spl.zp
error in accessing input file: laptop_0.spl.zp, in: treat_file()

I created the image by the following commands

mkdir /mnt/klons
mount –t smbfs –o username=administrator //138.245.76.1/Muster-PCs /mnt/klons
zsplit -s 1.9G -N laptop -o /mnt/klons -d -r /dev/sda1

and then on an identical laptop I executed the same mkdir- and mount-commands and then

unzsplit -D /dev/sda1 /mnt/klons/laptop

This was my second try to use zsplit/zunsplit. Durind my fist try just before I cloned successfully between the same two laptops but I set the full sda instead of sda1 only in the command above. sda consists of a 20GB partition sad1 with Windows XP at NTFS and a 60GB data partition sda2 also NTFS. Furthermore just before my second try I filled the empty space on sda1 nearly completely with 10MB-files containing only zeros in order to get a better compression for the image. //138.245.76.1/Muster-PCs is a folder on a Windows NT server.

The question is: Why did I succeed with my first try but not with the second?

I am not a very experienced linux user. Thanx for any help!
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[jurij]

Hi wolfgangbeyer,

for analysis of the particular situation it would be surely better if you could supply some portion of text from the debug.log. Some more information could be very helpful in this case.

But anyway, the error message: “error in accessing input file:...� means following: before opening of the input-file, in your case it is “laptop_0.spl.zp�, the program checks whether this file is accessible for any operation or not, only if the check is positive unzsplit (zsplit do it in exactly the same manner) opens this file for read/write operation.

In your case there was a problem in accessing this file, therefore this error-message.
The possible causes could be:
1. user-permissions problem; it means for this access check of your target file (laptop_0.spl.zp) read-permissions are required on the file itself for the user who started unzsplit. Furthermore, execute (search) permission is required on all of the directories in path that lead to this file. (For a directory, the Execute bit grants you so-called Search Permission, meaning that you have authority to use names in that directory in a pathname.)
2. Wrong path to target file.
3. The part of this path contains a component which is does not exist.
4. Hardware problem; short- or long-term inaccessibility of the device were your file “laptop_0.spl.zp� resides.

It does not matter if you use a device (as /dev/sda) or a partition (as /dev/sda1) for your backup/restore operations – both are allowed to use, so here could not be a problem for you.

I am sure it is an access problem initiated by wrong permissions or by hardware, which could result in access error.

Please post here if you could resolve your problem.

Regards,
Jurij

[wolfgangbeyer]

Hi Jurij,

The full content of debug.log is

27-06-2006 13:43:19 unzsplit: version: 1.2.0
27-06-2006 13:43:19 unzsplit: start of operation
27-06-2006 13:43:19 unzsplit: read/write buffer size: 64 kibibyte (65536 bytes).
27-06-2006 13:43:19 unzsplit: inflating laptop_0.spl.zp
27-06-2006 13:43:20 unzsplit: error in accessing input file: laptop_0.spl.zp, in: treat_file()
27-06-2006 13:43:20 unzsplit: not succeeded..., error in operation!
27-06-2006 13:43:20 unzsplit: end of operation

obviously I have the all rights to read and write /mnt/klons/laptop_0.spl.zp. I tested this by the commands

cat /mnt/klons/laptop_0.spl.zp
rm /mnt/klons/laptop_0.spl.zp

The laptops are Amilo Pro V2040 (Fujitsu & Siemens).

[jurij]

Hi Wolfgang,

in my first post I have noticed an error, not write-permissions are required for the file in your case “laptop_0.spl.zp� but only read-permissions are sufficient. I have it already corrected.

I see from the log text, that there is at least 1 second between the start of unzsplit-operation and error message after not successful access try:

27-06-2006 13:43:19 unzsplit: inflating laptop_0.spl.zp
27-06-2006 13:43:20 unzsplit: error in accessing input file: laptop_0.spl.zp, in: treat_file()

Normally, if the access-try returns an error, caused by permissions- or by hardware-problem, it should follow in the same second. So I would expect rather this situation:

27-06-2006 13:43:19 unzsplit: inflating laptop_0.spl.zp
27-06-2006 13:43:19 unzsplit: error in accessing input file: laptop_0.spl.zp, in: treat_file()

I think that there could be a samba based access problem. I am sure if you would do the same try using for example a partition on locally plugged USB-device, mounted to the same directory “/mnt/klons� it would do the job properly. Remember please, on NTFS partitions only read operations (not write-) could be done from the linux environment..
So I can only guess that samba connection could produce some access problems. What I think would be a candidate, the time deferred return for the function stat() which is interpreted as an error. In cases you have a very fast samba connection you will be able to do an unzsplit-operation. If the samba connection become a bit slower – you can get this access-error.

I think some experiments would help here to get the definite answer.

Regards,
Jurij

[wolfgangbeyer]

Hi Jurij,

This 1 second difference can be also a simple rounding effect. I later observed nearly only versions of debug.log with identical time stamps for all 7 entries.

I only have very few knowledge of Linux. How do I mount an external USB-Disc?

mount –t ntfs /dev/usb/lp0 /mnt/klons

does not work. With

cat /proc/partitions

I don’t see any additional USB-Device. Until now I was working only with the konsole after booting with "knoppix 2". By the way it is strange for me as Windows user to have to care about timing problems for net data access :-(.

regards

[jurij]

Hi Wolfgang,

I see, surely this can be rounding effect or an exact point of time between two seconds....
So, this time-deferred-return problem was only my assumption for your case. I can remember that one user has emailed me sometimes ago about nearly the same access problem as you have. He also has used samba connection to do a backup remotely. Therefore I think this problem has definitely something to do with samba but what? It is a good question...

What about external USB-device...
First, to be able to mount USB-device this device should be recognized by kernel during the boot sequence. If it is not a case you cannot use it. The simple way to see whether your device is visible, do the following:
fdisk –l (please be sure that option –l consist of small L)
After issuing this command you will see all known (visible) devices. If your USB-device is not visible, you have at least two alternatives: change your kernel with one which has USB-device-recognition (compiled in USB driver) or change KNOPPIX CD to newest one. For sure you will be able to see your USB-device after that.

Then if this is a case, I would suggest you to make a partitioning of this device (may be better under Windows). Make one partition which is big enough to contain your images and format it as FAT32. It is better because you can read and write to this partition from linux environment.
After that you: plug-in your USB-device, start KNOPPIX, isuue: fdisk –l if you see something like /dev/sda (USB-devices are often recognized as scsi devices) than you can use your device.
(We suppose that this new partition is the first one on your device)
Than do mounting: mount –t msdos /dev/sda1 /mnt/klons.
After that you can access the new partition under /mnt/klons.

Regards,
Jurij

[wolfgangbeyer]

Hi Jurij,

Thank you for these hints. I am for about 4 weeks in holidays and will continue the discussions in august.

regards