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EXT3 Volume Access

Hello All,

This is my first post on Exchange experts. My issue is with a Linksys NLSU2 NAS device running with a Maxtor 160GB drive, which was stored within a non-name drive enclosure. I've had both items for about a year now. The External drive is conneted to the NAS via a standard USB 2.0 cable.  I recently had a failure with the NAS device whcih I'm investigating with Linksys.  My concern is how to acces the files on my drive in the meantime.  From what I can see the drive has two logical volumes setup.  I've used some of the EXT3 emulator for Windows app's available on teh web but I can only access the initial volume ( Boot volume  I think) not the secondary which houses all of my data.  I'm new to Linix and EXT3 and need some help.  

At ths point I believe the drive is fine, I just can't access the data in the second logical volume.  Any Suggestions?

Thanks,

John
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ahoffmann
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I'd not access the disk with windows.
Said this, I'd also mount the partitions with ext2 in read-only-mode.
If you plug the disk to Linux, can you access them using fdisk? NOTE: fdisk on Linux NOT WINDOWS !!!
Create a mount point:

mkdir /mnt/exthd

mount it!

mount -r -t ext2 /dev/hdx /mnt/exthd

mounting as ext2 will work as ext3 is ext2 with journalling.

HTH:)
Ooops - the device will be /dev/sdxx (or similar where xx = a1,a2,a3,b1,b2,b3 or similar) as it is a usb dev.

HTH:)
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edkim80

if it truly is a "logical volume" i would suspect you could not access it via /dev/sdx..  I have never dealt with LVs on external drives, but I would assume you'd access them similiarly to standard LVs.  
plug it into a linux machine (you can use a live linux CD such as knoppix) and see what the output of "fdisk -l" is.  you may need to use the commands pvdisplay, or lvdisplay to see what their /dev designations are.
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ASKER

In order to create the mount point will I need an OS running some form of Linux, attach the drive then mount it?  Can this be doen using Windows Xp with some kind of EXT3 explorer?
You're going to need an Linux OS... there are self contained OS's that can be booted from and run from a CD.. check out www.knoppix.net
Thanks I'll give it a try now!!!
Get explore2fs:

http://uranus.it.swin.edu.au/~jn/linux/explore2fs.htm

A free windows explorer for ext2 partitions.

Total commander for windows also has an ext2 plugin:

http://www.ghisler.com/plugins.htm

HTH:)

as said before, don't use Windows 'cause most drivers are still experimental
Hey pjedmond, I tried that explore2fs but it only sees the first logical volume (Boot drive) not the second one which contains my data.  Do I have it configured incorrectly?
ahoffman - I agree - but as long as you don't write to it, it shouldn't cause a problem.

FeitelbergInsurance - from what you've said, I consider your best bet to be a knoppix live CD solution. Using the (linux) fdisk command you should be able to identify the partitions. Once you've done that, you should be able to mount and copy your data.

I've loaded the knoppix from CD (Pretty Sweet!!!).  I noticed that it did pickup both the hda1 (My data Volume) and hda2 ( Boot volume).  Unfortunatly hda2 opens beautifully but hda1 won't mount for some reason.  

I tried using the "mount -t ext2 /dev/hda1 /mnt/hda1" and mount -t ext3 /dev/hda1 /mnt/hda1" command but I keep receiving the following:   wrong fs type, bad option, bad superblock on /dev/hda1, missing codepage or other error

Is their someway to verify if I do infact have a corrupt file of somekind?  Will the fdisk confirm this?  I'm new to Knoppix so any written commands would be most helpful.....
fsck /dev/hda1
will do a filesystemcheck on hda1.
what is the output of "fdisk -l"?
are you sure the disk is ext2 filesystem?  as you called it a "logical volume" before which is different...
I ran the  fsck /dev/hda1 and this itthe output I received:

fsck 1.38 (30-Jun-2005)
e2fsck 1.38 (30-Jun-2005)
fsck.ext2:  Attempt to read block from filesystem resulted in short read while trying to open /dev/hda1
Could this be a zero partition?

I also ran the fdisk -l and got:

Disk /dev/hda:  163.9 GB, 163928604672 bytes
255 heads, 63 sectors/tracks, 19929 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot        Start                End                   Blocks              ID       System
/dev/hda1         1                     19899               159838686        83       Linux
/dev/hda2          19900           19914                  120487+           83       Linux
/dev/hda3         19915            19929                 120487+            82      Linux swap/ solaris

I also got the name o fthe Data Recoivery product that does see the files system.  Its called "Stellar Phoneix Linux"  http://www.stellarinfo.com/

Is this drive recoverable without the purchase of this product.

Please advise!!!
what does
dd if=/dev/hda1 of=/dev/null bs=1k count=1000000
report?

Do you have another HDD with at least 160 gigs available? I'd recommend to copy the first partition to another medium before tinkering with it furthermore.

-XoF-
unfortunately dd fails if there're bad secrors somehow ...
Use dd_rescure from http://www.garloff.de/kurt/linux/ddrescue 
dd if=/dev/hda1 of=/path/to/huge/disk/hsda1.dd bs=1k count=10000000
then you can try to mount /path/to/huge/disk/hsda1 as lop back device
I'll gte my hands on another 160GB drive. I'll try the DD command and the DD_rescue.  Will I need to run this app from the Knoppix desktop?  If so which of the versions listed below (from the dd_rescue site) will do the job?

How do I run it on Knoppix if its booting from CD?

    * A source tar ball (1.11)
    * A source RPM (1.11)
    * A binary i586 RPM (1.11 for SuSE Linux 8.1 +)
    * A binary x86-64 RPM (1.11 for SuSE Linux 8.1 +)
    * A source tar ball (1.10)
    * A source RPM (1.10)
    * A binary i586 RPM (1.10 for SuSE Linux 8.1 +)
    * A source tar ball (1.04)
    * A source tar ball (1.03)
    * A source tar ball (1.02)
    * A source tar ball (1.01)

If this option lets me recovery some, if not all of the data, I'll be VERY happy.  
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XoF

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Will do XoF!!  

I've lcoated a new 160GB drive I'm going to purchase to attempt the recovery should the dd option fail. Does the new drive have to be Identical (Make , Model, Size and Manfacturor) to the problem drive?? The existing drive is a Maxtor 7200 RPM 160GB drive.  The new unit is a Seagate 7200RPM 160GB drive.  
post output of
fdisk -l
when both disks are attached.
Just picked up my new drive.  I'll post the output of the commads above for your review. Thanks!!
I just wanted to confirm the following setup when I attempt to run the dd via Knoppix:

Primary Master:    CD-ROM
Primary Slave:     None

Secondary Master:    Corrupt 160GB Maxtor Drive
Secondary Slave:      New 200GB Seagate Drive

Will I need to format the new 200GB drive with EXT2/EXT3 at root before proceeding?   My new drive is larger than the  original drive.  Is this a problem?  

Thansk again for the help!!!