[nzlug] Ext3 file system

[cr]

Can anyone tell me - is there any quick easy way to tell if a filesystem has 
been 'converted' to Ext3?   Is it safe to run 'tune2fs' on a system that's 
ext3 already?

(I ask because, while I was doing an install of the latest Debian Sarge on a 
spare partition on /hdc, and sorting out Grub menus and fstabs etc, my first 
hard drive /hda which was Win98 formatted coincidentally gradually died - no 
great loss except that it caused me total confusion (everything progressively 
stopped booting!) and seems to have screwed up writes to my previous Linux 
system on /hdc1 and - quite possibly - after I elbowed /hda with extreme 
prejudice and got things going again I compounded the error with unwise 
fsck-ing.   So /hdc1 is munged, too  :(       All my data is safe on another 
drive (thank goodness) except for recent emails and, of course, my old fstab 
file.    And of course I can't remember which partitions were ext2 and which 
were ext3.   (Currently they're all mounted ext2, which I gather should be 
safe).

cr
... making a mental note to do a full backup just _before_ the next 
crash... ;)