[parted-devel] Understanding AFFS

[Phillip Susi]

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I've been investigating why parted's rescue operation is so slow and
it seems that it is largely due to AFFS, so I am trying to understand
it a bit.  I notice that it appears to read the first 16 sectors of
the disk ( not the partition or potential partition ) looking for some
sort of "rigid disk" block.  Why is this?  Wouldn't this prevent the
possibility of having such a filesystem on a gpt partitioned disk, or
a disk with grub installed?  Or a loop image?  I checked the kernel
affs code and it has a different way of computing the fs block size (
which seems to be the reason for reading the rigid disk block ).

Another reason for the slowness is that affs registers 15 different
variants and each one must be probed separately resulting in 15 times
the number of reads.  Is it really necessary to differentiate between
all of these sub types in the output of parted print?

Also where can I find tools for creating such a filesystem for testing
purposes?

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