[SATLUG] Re: 2GB file size limit. EXT3 or SMB?

[Chuck]

Yea,

But is it really worth it to gzip that data???

Gzip, just like ZIP, RAR, LHC, and all the other Winblows variants works
better on "predictive" files.  Text files and some types work great. 
Straight binary files don't work worth a damn.  I've seen large binary
files GROW when passed through a "compressor".

DD'ing a drive will produce a straight binary output which won't be
readily compressible.  Have you tried the dd and split with and without
compression?  I'll bet that you'll find the small amount of drive space
saved is hardly worth the extra time & CPU power of doing the
compression.


Chuck




On Sat, 2005-08-13 at 10:46, masterr at gmail.com wrote:

    On 8/13/05, masterr at gmail.com <masterr at gmail.com> wrote:
    > 
    > I have an interesting problem. I am backing up a computers hard drive that 
    > has about 5 GB of data on it with Ubuntu Live by using the dd command 
    > outputing to a SMB share (don't have NFS installed) on to another computer 
    > using the EXT3 filesystem with 60GB of free space. `dd if=/dev/hda 
    > of=smb/backup/henry-8-13-05.img`. This works fine and dandy untill the 
    > resulting image of the drive reaches 2GB in size. Is this 2GB a limit of 
    > samba, of EXT3, dd, or something I am not seeing? Does anyone know?
    > 
    > dd gives me "File size limit exceeded"
    > 
    > I could get around this by passing it through split, `dd if=/dev/hda | 
    > split -b 2000m - smb/backup/henry-8-13-05.img`, but if I do this I don't 
    > know of a way to compare the MD5 sums of the drive to the image. Can md5sum 
    > compute the combined sum of a split file after it has been split? If so then 
    > there is a solution, but I have no clue how to do it.
    > 
    > Also, if it was possible, it would like to be able to gzip the file before 
    > splitting it and still be able to compute the md5 sum of the originating 
    > .img from the split gzipped drive image. I can do this with `dd if=/dev/hda 
    > | gzip -c | split -b 2000m - smb/backup/henry-8-13-05.img`, but again, I 
    > have no idea how to check the md5 sum of the originating image to compare to 
    > the drive.
    > 
    > It would be great to get the md5 sum after it has been split, but I 
    > suppose if there is no way to do it I can pop another bigger hard drive into 
    > the comp, make the image to it, then compare the md5 sum locally (assuming 
    > the 2gb limit wasn't for ext3). But thats a pain.
    > 
    > Anyway, thanks
    > -Jonathan Hull
    > 
    > -- 
    > Jon/MasteR
    > masterr at gmail.com
    > 
    > i am a n00b 
    
    
    I did some more googleing and tinkering and I think I may have found a 
    solution on my own.
    
    To make the gzipped split image do 
    `dd if=/dev/hda | gzip -c | split -b 2000m - smb/backup/henry-8-13-05.img`
    and then to compute the md5sum do
    `cat henry* | gzip -dc | md5sum`.
    
    Anyone think this will work?
    
    -- 
    Jon/MasteR
    masterr at gmail.com
    
    i am a n00b
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