Re: [Mldonkey-users] Disk space preallocation

[Markus Hitter]

Am Dienstag, 06.05.03 um 15:14 Uhr schrieb Martin:

> Markus Hitter wrote...
> > Let me guess how my files got corrupted:
> > 2) Either by copying the files around or with progessing downloads the
> > disk ran out of space.
>
> Either way the files should not get corrupted...

Well, that's easy to demonstrate:

Nobile:~/MLdonkey2.4rc8/temp$ mv 5C1ED4A773DBAD98D32AAABC2118AA04 temp
Nobile:~/MLdonkey2.4rc8/temp$ cp temp 5C1ED4A773DBAD98D32AAABC2118AA04
/Volumes/Party: write failed, file system is full
cp: 5C1ED4A773DBAD98D32AAABC2118AA04: No space left on device
Nobile:~/MLdonkey2.4rc8/temp$ ll temp 5C1ED4A773DBAD98D32AAABC2118AA04
-rw-r--r--  1 mah  staff  127926272 May  6 17:57 
5C1ED4A773DBAD98D32AAABC2118AA04
-rw-r--r--  1 mah  staff  445247747 May  5 21:29 temp

The 5C... file is corrupted now. Perhaps, "cp" should remove the 
partially written file but that is how it works on OS X at this time. 
Can't speak for other OS's.


> i do this once a month and fsck sometimes finds some broken inodes 
> (which can be repaired) only on the drive mldonkey runs on....

... then this is something we should have a closer look at. Hopefully 
we can find some test case which triggers such a broken inode.


Am Dienstag, 06.05.03 um 15:24 Uhr schrieb Pierre Etchemaite:

> here's the expected "path of trust": ...

That one seems reasonably to me.

What's missing is a "path of recovery" for the various failures. 
MLDonkey already seems to detect them fine, just has too few ideas how 
to recover.

> Since the number of subhashes is computed from the temp file size, ...

Not a good idea, IMHO. When metadata is lost, something went wrong and 
I whouldn't trust anything in temp/ . See above.

> Also, 17 is both bigger than 15 and 9. If I'm not mistaken, and that 
> it's really a chunk number, I hope those messages aren't related to 
> the same file, ...

No, they aren't :-)


Well, I'll shut up for now until I can come along with more test cases 
or at least a self built client. MLDonkey is a great piece of software, 
after all.


Have fun,
Markus

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Dipl. Ing. Markus Hitter
http://www.jump-ing.de/