There are two ways to do this:
Create a .dsk-file of size X-MB (with dd), then make a JSF-filesystem on that file, with option O (OS2 compatibility - = case insensitive)
Then loop-mount that file into a desired folder.
To create a JFS filesystem, you will need to have jfs-utils installed.
On Ubuntu, you can do this with:
sudo apt-get install jfsutils
Now you need to create an empty file with some size, e.g. 1 GB
dd if=/dev/zero of=/tmp/test-jfs.img bs=1048576 count=150
Now you need to create a jfs-partition in /tmp/test-jfs.img
Note: All data in /tmp/test-jfs.img will be lost !
mkfs.jfs -O /tmp/test-jfs.img
Then you neet to recursively create a mount directory (/mnt/jfs):
mkdir -p /mnt/jfs
Then you need to loop-mount (not recommended in production) that partition in /mnt/jfs
mount /tmp/test-jfs.img /mnt/jfs -t jfs -o loop
If that was successful, you can now create a partition, e.g. with touch
if you ls, you see that it's there
if you ls with
You've testet successfully, and can now unmount the partition:
And delete the temp file
When you install the OS, manually partition the disk, and create another partition with format JFS, which you mount to wherever you want to have it.
When everything is up and running, you can reformat that partition with (warning - this will erase all data on that partition - make sure you selected the proper one, and don't have any data on it, yet):
unmount the mounted partition
mkfs.jfs -O /dev/hda5
remount the partition
mount /dev/hda5 /web
and you get the new partition-uuid.
Now go to /etc/fstab, and replace the old uuid for /dev/hda5 with the new one.
If you're doing this wrong, see also
Welcome to emergency boot mode...