Growfs

Here is a breakdown on how to grow an ffs filesystem.

Let's make a big file which will represent our disk, 32MB in size:

# dd if=/dev/zero of=disk bs=32m count=1
1+0 records in
1+0 records out
33554432 bytes transferred in 0.164 secs (204133427 bytes/sec)
# vnconfig -cv svnd0 disk
svnd0: 33554432 bytes on disk

/dev/svnd0c is now our disk. Create a partition on it, this time we'll make it too small so that there is space left on the disk:

# disklabel -E svnd0
disklabel: Can't get bios geometry: Device not configured 
Initial label editor (enter '?' for help at any prompt)
> a
partition: [a]
offset: [0]
size: [65536] 32768
FS type: [4.2BSD]
> p
device: /dev/rsvnd0c
type: SCSI
disk: vnd device
label: fictitious
bytes/sector: 512
sectors/track: 100
tracks/cylinder: 1
sectors/cylinder: 100
cylinders: 655
total sectors: 65536
free sectors: 32768
rpm: 3600
16 partitions:
#             size        offset  fstype [fsize bsize  cpg]
  a:         32768             0  4.2BSD   2048 16384   16 # Cyl     0 -   327*
  c:         65536             0  unused      0     0      # Cyl     0 -   655*
> q
Write new label?: [y] y

Write the filesystem on it:

# newfs /dev/rsvnd0a
Warning: cylinder groups must have a multiple of 8 cylinders
Warning: 32 sector(s) in last cylinder unallocated
/dev/rsvnd0a:   32768 sectors in 328 cylinders of 1 tracks, 100 sectors
        16.0MB in 1 cyl groups (328 c/g, 16.02MB/g, 2048 i/g)
super-block backups (for fsck -b #) at:
 32,

Mount the filesystem and populate it with files:

# mount /dev/svnd0a /mnt
# cd /mnt
# cp /bin/* .
# cp /sbin/* .
/mnt: write failed, file system is full
...
# df .
Filesystem  512-blocks      Used     Avail Capacity  Mounted on
/dev/svnd0a      32156     31992     -1440   105%    /mnt
...
# df -i .
Filesystem  512-blocks      Used     Avail Capacity iused   ifree  %iused  Mounted on
/dev/svnd0a      32156     31740     -1188   104%     134    1912     7%   /mnt
# cd /tmp
# umount /mnt

Note the reason the filesystem Capacity changed from 105% to 104% is because the author had deleted some files and represented this with "...". Don't get confused!

Now we grow the partition:

# disklabel -e svnd0
# growfs /dev/rsvnd0a
We strongly recommend you make a backup before growing the Filesystem
Did you backup your data (Yes/No) ? Yes
new file system size is: 16384 frags
growfs: 65536 sectors in 656 cylinders of 1 tracks, 100 sectors
       32.0MB in 2 cyl groups (328 c/g, 16.02MB/g, 2048 i/g)
superblock backups (for fsck -b #) at:
 32832

Mount it and check it:

# mount /dev/svnd0a /mnt
# cd /mnt
# df .
Filesystem  512-blocks      Used     Avail Capacity  Mounted on
/dev/svnd0a      64348     31740     29392    52%    /mnt
# df -i .
Filesystem  512-blocks      Used     Avail Capacity iused   ifree  %iused  Mounted on
/dev/svnd0a      64348     31740     29392    52%     134    3960     3%   /mnt

Conclusions:

growfs not only increased the data space on the filesystem but also the index (inodes).