How to compare md5sums from compressed image of a drive and the md5 of the drive itself?

I have a compressed image of a 73 GB drive in solaris 10. I need to ensure the image is identical to the compressed image. The drive is unmounted and at c1t1d0s2 . The image was created using; dd if=/dev/rdsk/c1t1d0s2  | gzip > /mnt/storage1/image1.gz
I've computed md5sum using; digest -a md5 /mnt/storage/image1.gz > /mnt/storage/image-md5
I need to compare this to the drive itself to ensure it is the same.
Here is an idea I have:
 digest -a md5 | gzip -dc /dev/rdsk/c1t1/d0s2 > /mnt/storage/drive1-md5
 
Also, I'm working at the command line and can't install more apps/utilities on this server.
finallydidit99Asked:
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coredatarecoveryConnect With a Mentor Commented:
the syntax may be gzip -dc /dev/rdsk/c1t1/d0s2|digest -a md5>/mnt/storage/drive1-md5

otherwise it looks like you are piping your data the wrong way to me.

(It looks like a good idea to me anyway.)
(I am unsure if the digest perl script will accept a piped raw data feed from gzip.)

But the theory is sound.

Either way, if either will run and the md5 matches, you are done and you know you have a good backup.

(I'll hang out here and listen for another expert to chime in, as I am very interested in this answer myself)

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coredatarecoveryCommented:
You could always extract it to a scratch disk and compare the md5 checksum.

(that would be a valid way of getting your md5 checksum too)
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finallydidit99Author Commented:
Thanks for the info. I'll give that a try. One of the limitations I have is that I do not have any extra space to work with. I have 2 servers each with 4 drives that I made images for. These images are stored on 2 drives on a 3rd server. On the third server, I have a single drive(c1t0d0) with Solaris 10 installed, 2 drives for the images (c1t1d0, c1t2d0), and then I am rotating the the drives to be imaged one by one in the other slot (c1t3d0). All te drives are 72GB.




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coredatarecoveryCommented:
You could mount an External 1 Tb drive as a scratch.

(USB would take approximately 4.5 hours to extract a 72 gb image to disk)
(you could then compare the /dev/sdc1 with /dev/sdd1  as an example (md5 the partition instead of the drive itself)

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finallydidit99Author Commented:
I would love to be able to mount an external USB drive!, but... I have not been able to do so. I have a solaris 10 system without the ability to install additional software.  Could info on mounting a Wd500GB drive be given also? I'll definitely up the points for the extra help.  Thanks!
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coredatarecoveryCommented:
I was hoping it would mount without software in solaris, I've got solaris running here on a pc.
(You must be running a sun system)

do you have a wd500gb drive with firewire (I'm hoping your system has a firewire port)
So, you don't have any usb ports?

(Solaris will show the device under /dev once you plug the drive in)

so if you do a ls -l /dev>whatdevicesdoihave.txt
and then plug it in and do it again, but change the name of the text file, you can compare to see what device names are.

in this case you are in /dev/rdsk

What ports do you have available to you on this unit, what model sun are you running?
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finallydidit99Author Commented:
'Sorry for the delay. I know it's been a couple of days but I haven't gotten back to this yet. I'll let you know when I do.
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coredatarecoveryCommented:
No Problem, I'll check back.
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