[ale] How to check files on CDROM?

Tom Freeman tfreeman at intel.digichem.net
Thu Feb 15 17:57:48 EST 2007


Something like below is what I _should_ have started with, and didn't.  
In the future I hope to implement something similar. Challenge  
currently is to check the backup file copies at an off site location at  
a later date. That way, should the CD versions start to decay, some  
recovery may be attempted before everything is gone/lost/destroyed.

Well, I should have asked the original question better then, shouldn't  
I have? Guess it wasn't completely clear to me either. <<sigh>>

I need to work up a moderately clever backup to cd script incorporating  
the idea below. Especially since it will cover _all_ data types which  
might be backed up to CD.

On 02/15/2007 05:14:17 PM, Jerry Yu wrote:
> I don't think it is too late to use checksum. Here is how I usually  
> does for
> my backups
> 
>   - for files on disk
> 
> cd  /MyPictures && find . -type f -iname "*.jpg" -exec md5sum {} \;   
> | sort
>> md5sums.disk
> 
>   - for files on CD/DVD
> 
> cd  /mnt/cdrecorder && find . -type f -iname "*.jpg" -exec md5sum {}  
> \;  |
> sort  >> md5sums.cd
> 
>   - compare the checksum
> 
> diff md5sums.disk md5sums.cd  | less
> 
> You need to repeat step 2  for all CDs and to re-sort md5sum.cd file  
> after
> all CDs are done.
> 
> 
> On 2/15/07, Christopher Fowler <cfowler at outpostsentinel.com> wrote:
>> 
>> Will convert fail on bad data?
>> 
>> foreach $file in /mnt/cdrom
>> do
>>   convert $file /tmp/1.png
>>   rm /tmp/1.png
>> done
>> 
>> Just a guess since it tries to read the data to convert it.
>> 
>> Maybe if it succeeds then you could start and md5sum catalog then.
>> 
>> 
>> On Thu, 2007-02-15 at 13:52 -0500, Thompson Freeman wrote:
>> >
>> > This may be a bit of an oddball question when I get to it.
>> >
>> > I just spent an hour backing up my girlfriend's pictures on
>> > her computer, roughly 5 CD's worth. Since CD's can slowly
>> > go bad, I got wondering is there a reasonable way to let a
>> > computer verify each file?  In this case jpegs but make it
>> > a general case.
>> >
>> > Obviously, if I had planned it properly each file could be
>> > run through a checksum procedure _before_ burning the disk.
>> > As it is now, I need to open each file individually and
>> > look at it. This can be automated to a degree, but I still
>> > need to eyeball each one to verify that the picture is
>> > complete and still there on the disk. Since there should be
>> > better than 10,000 pictures, that represents a fair chunk
>> > of time I'd prefer to use goofing off some other way.
>> >
>> > Thanks for any ideas, and I appreciate the use of
>> > everybody's bandwidth.
>> > _______________________________________________
>> > Ale mailing list
>> > Ale at ale.org
>> > http://www.ale.org/mailman/listinfo/ale
>> 
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