filesystem block size under AIX 3.1

[Jonathan Eunice]

Richard Johnson (raj at pollux.ncgia.ucsb.edu) writes:
| If you create a symlink to a file where the reference name in the symlink
| is less than 48 characters long, I'm told (by people in Austin) that the info.
| is stored in the inode.  However, if it's more than 48 characters long the
| system allocates the smallest "block size" chunk of the filesystem for that
| file.  This "smallest block size" is 4K!  This means that if you are creating
| a lot of symlinks (such as symlinking the X11 distribution [the one from MIT,
| not the smaller copy from IBM] for compilation of different machine types), 
| you can eat up disk space REAL FAST!  This is a problem!

It's my understanding that the JFS block size is fixed at 4 KB, and
that disk block fragmentation (a la BSD UFS) is not available.  So,
tiny files and sym links (in your situation, really just special kinds
of tiny files) devour disk space.  This is one (significant) reason
those ~120 MB disks are de-emphasized -- too much space wastage to make
them relevant/useful.  

Perhaps in a future version of AIX JFS will implement fragmented
blocks, or IBM will offer the BSD FFS/UFS as an option.  I'm afraid
that the current solution appears to be buying more disk.