HAMMER: you can mount_hammer a UFS that was a hammer fs before

[Jan Lentfer]

Bill Hacker schrieb:
Jan Lentfer wrote:
If a partition contains a hammer fs and you newfs it to a UFS you can 
afterwards still mount it as hammer fs.
You can even still run hammer info and write data on the partition 
(tried with dd).
?  'dd' does not know or care anything about a fs.

What happens if you not only 'newfs' to UFS, but actually *write* to it 
AS a r/w UFS mount? (e.g. - not with 'dd').

If hammer fs can 100% recover from that, there is witchcraft afoot....


Actuall I tried the other way and it worked: You can write data on the 
mount_hammer'd UFS with if=/dev/zero of=/mnt/ZEROS (which cares about 
the fs), umount it and mount (UFS) it. Then you will not the the created 
file with ls. unmount again, mount_hammer, ls and ... surprise ... data 
will be there  again. That is nice, isn't it.

Cheers

Jan