vndcompress(1) - NetBSD Manual Pages

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VNDCOMPRESS(1)          NetBSD General Commands Manual          VNDCOMPRESS(1)


NAME

     vndcompress, vnduncompress -- compress/uncompress file system images
     to/from cloop2 format


SYNOPSIS

     vndcompress [-cd] disk/fs-image compressed-image [blocksize]
     vnduncompress [-cd] compressed-image disk/fs-image


DESCRIPTION

     The vndcompress program compresses an existing file system image into a
     cloop2 compatible compressed file system image.  An optional blocksize
     can be given.  If omitted, the default of 64kB is used.

     The vnduncompress command decompress a cloop2-compressed file system
     image back into a regular image.

     The file system images that can be handled are not limited to any spe-
     cific file system, i.e. it is possible to handle images e.g. in ISO 9660
     or UFS/FFS format.  File system images in the cloop2 format are intended
     to be used with the vnd(4) driver in compressed mode as configured by the
     -z option of the vnconfig(8) program, and later mounted with the appro-
     priate -t option to mount(8).


OPTIONS

     The following options are available:

     -c      Always compress, even if the program was started as
             vnduncompress.

     -d      Always uncompress (decompress), even if the program was started
             as vndcompress.


EXIT STATUS

     The vndcompress and vnduncompress utilities exit with one of the follow-
     ing values:

     0     The operation was performed successfully.

     1     An error occurred.


EXAMPLES

     To compress an existing CD-ROM file system image, run the following com-
     mands:

           # vndcompress netbsd.iso netbsd.izo

     Note that the resulting compressed image cannot be mounted directly via
     NetBSD's vnd(4) and mount_cd9660(8) commands any longer.  Instead, you
     will have to use the -z option of vnconfig(8).

     The following example decompresses an existing CD-ROM file system image
     that was compressed in the cloop2 format into a regular file that can
     then be mounted:

           # vnconfig vnd0 KNOPPIX.iso
           # mount -t cd9660 -o ro /dev/vnd0d /mnt
           # vnduncompress /mnt/KNOPPIX/KNOPPIX /var/tmp/knoppix.iso
           # umount /mnt
           # vnconfig -u vnd0
           #
           # vnconfig vnd1 /var/tmp/knoppix.iso
           # mount -t cd9660 -o ro /dev/vnd1d /mnt
           # ls /mnt
           .rr_moved cdrom     floppy    lib       opt       sbin      usr
           bin       dev       home      mnt       proc      sys       var
           boot      etc       initrd    none      root      tmp       vmlinuz
           # umount /mnt
           # vnconfig -u vnd1

     As an alternative, if your vnd(4) was compiled with VND_COMPRESSION, you
     can use vnconfig(8) to access the cloop-compressed image directly, e.g.,

           # vnconfig vnd0 KNOPPIX.iso
           # mount -t cd9660 -o ro /dev/vnd0d /mnt
           # vnconfig -z vnd1 /mnt/KNOPPIX/KNOPPIX
           # mount -t cd9660 -o ro /dev/vnd1d /mnt2
           # ls /mnt2
           .rr_moved cdrom     floppy    lib       opt       sbin      usr
           bin       dev       home      mnt       proc      sys       var
           boot      etc       initrd    none      root      tmp       vmlinuz
           # df /mnt /mnt2
           Filesystem    Size      Used     Avail Capacity  Mounted on
           /dev/vnd0a    692M     692M        0B   100%    /mnt
           /dev/vnd1a    1.9G     1.9G        0B   100%    /mnt2
           # umount /mnt2
           # vnconfig -u vnd1
           # umount /mnt
           # vnconfig -u vnd0

     Note how the 1.9GB big filesystem on /mnt2 is mounted from the compressed
     file stored on the 692MB CD mounted on /mnt.  To create a compressed file
     system image of an existing directory and mount it, run:

           # makefs -t ffs include.fs /usr/include
           # vndcompress include.fs include.fs.cloop2
           # vnconfig -z vnd0 include.fs.cloop2
           # mount -o ro /dev/vnd0a /mnt
           # ls /mnt

     To undo the steps, run:

           # umount /mnt
           # vnconfig -u vnd0
           # rm /tmp/include.fs.cloop2
           # rm /tmp/include.fs


SEE ALSO

     gzip(1), vnd(4), mount(8), mount_cd9660(8), vnconfig(8)


AUTHORS

     The vndcompress utility was written by Florian Stoehr
     <netbsd@wolfnode.de>.  The vndcompress manual page was written by Florian
     Stoehr <netbsd@wolfnode.de> and Hubert Feyrer <hubertf@NetBSD.org>.

NetBSD 5.2                     December 12, 2005                    NetBSD 5.2