Re: shrinking a filesystem using resize_ffs(8)
Michael van Elst wrote: > jscha...@netmeister.org (Jan Schaumann) writes: > >$ sudo newfs -C 2 /dev/rvnd0a > > There is no '-C'. Maybe -O 2 ? Yes. :-) > But resize_ffs doesn't support shrinking FFS2 and should > complain when you try. > You tell resize_fsck the new size with -s and then > reduce the partition size accordingly. Ah, the order is first resize_ffs, then update the disklabel. So the order is: $ sudo newfs -O 1 vnd0a # start out with 1GB /dev/rvnd0a: 1024.0MB (2097152 sectors) block size 16384, fragment size 2048 using 6 cylinder groups of 170.67MB, 10923 blks, 21504 inodes. super-block backups (for fsck_ffs -b #) at: 33, 349568, 699104, 1048640, 1398176, 1747712, $ sudo resize_ffs -s 1048576 /dev/rvnd0a # shrink to 512MV $ sudo disklabel -e vnd0 # adjust disklabel $ sudo mount /dev/vnd0a /mnt $ df -h /mnt Filesystem Size Used Avail %Cap Mounted on /dev/vnd0a 504M 2.0K 479M 0% /mnt $ Nice, that works. Thanks! -Jan
Re: shrinking a filesystem using resize_ffs(8)
jscha...@netmeister.org (Jan Schaumann) writes: >Hi, Hi, >$ sudo newfs -C 2 /dev/rvnd0a There is no '-C'. Maybe -O 2 ? But resize_ffs doesn't support shrinking FFS2 and should complain when you try. >[ back to two '1048576' sized partitions ] >$ sudo fsck_ffs -y -f /dev/rvnd0b >[ all ok ] The 'b' filesystem was probably never changed but maybe trashed in a way that fsck doesn't understand. >$ sudo resize_ffs -v /dev/rvnd0b >No change requested: already 524288 blocks The superblock and partition agree. Nothing to do and nothing to check. >$ sudo fsck_ffs -y -f /dev/rvnd0a >** /dev/rvnd0a >CANNOT READ: BLK 2010160 >CONTINUE? yes The 'a' filesystem still thinks it is 1GB and you try to shrink it. But the disklabel already restricts access to the lower half. Any attempt to access data from the upper half fails. >$ sudo resize_ffs -v /dev/rvnd0a >resize_ffs: read failed: Invalid argument Dito. Shrinking requires access to all the data. >So... how do I shrink a filesystem? You tell resize_fsck the new size with -s and then reduce the partition size accordingly.
