rgutter Posted March 12, 2008 Report Posted March 12, 2008 After a system crash, uTorrent 1.7.7 can't seem to use my existing settings etc. and seems to think I'm a new user. The user files are in C:\Documents and Settings\Administrator\Application Data\uTorrent; when I exit my new uTorrent session, it builds new settings, resume and dht data files. Restoring the renamed .old versions to .dat doesn't help. I guess one or more of them were corrupted by the crash - is there any way to attempt a recovery? Thanks.
jewelisheaven Posted March 12, 2008 Report Posted March 12, 2008 Without backups, if your .old are useless, no. What do you mean restoring .old to .dat doesn't help? If the files are all < 1 KiB there is simply no data in them. Checking this is rather easy with Ultima's Bencoded File Editor (which uT config files all happen to be). Resume.dat stores all information for loaded torrents.
rgutter Posted March 12, 2008 Author Report Posted March 12, 2008 uTorrent seems to create backup files (i.e., restore.old) from its data files whenever the program is exited. When this problem first occurred this morning, the .old files "looked" okay - resume.old for example was 18Kb. So I closed uTorrent, deleted the new <1Kb resume.dat, renamed resume.old to resume.dat, and did the same for settings.dat and dht.dat. When I restarted uTorrent, though, it again opened with no settings or torrents, so I'm assuming the data files have been corrupted. I'm looking for some info on what they should look like so that I can attempt a repair with a hex editor.EDIT: Uh-oh. Never mind. I loaded resume.old into a hex editor and found 18Kb of nulls. Guess I'm SOL. Thanks anyways.
jewelisheaven Posted March 12, 2008 Report Posted March 12, 2008 Ultima made a nice utility called Bencoded File Editor (BFE for short). In my experience NULL indicates a problem with either the controller or your Windows got b0rked, heh.Thats why I backup uT religiously... and as long as you know where to [backup the settings from you're good to go.It's unfortunate you had to learn the hard way about crashing being bad for your settings, and it's unfortunate there are too many ways to crash to make detecting them viable. Of note: the resume is resaved every 30 seconds.
rgutter Posted March 14, 2008 Author Report Posted March 14, 2008 Thanks for the info. In the old days (yes, I'm one of those) we used to keep files open through rewrites because of disk latencies. Not a best practice anymore. I'm glad uTorrent updates resume.dat frequently, but it should also preserve the previous version upon each update, and more importantly flush and close the file and release the file handle - that would prevent the OS or the controller from corrupting the files when it goes south.
Firon Posted March 14, 2008 Report Posted March 14, 2008 The previous version is stored (as the .old file), but sometimes that fails too.
rgutter Posted March 14, 2008 Author Report Posted March 14, 2008 On each update? Or just when the program closes? Anyways, thanks to you and to jewelisheaven for the quick feedback
jewelisheaven Posted March 14, 2008 Report Posted March 14, 2008 Hmm? After you open uT you have a 30 second window to "salvage" the previous resume.dat.oldAfter that, you will get the new resume.dat saved as resume.dat.old and hence useless information.
rgutter Posted March 14, 2008 Author Report Posted March 14, 2008 Not, I'd suggest, an ideal design. Clearly, the program when started knows when it's encountered a corrupt resume.dat - that's why it ignores it and brings up the initial "test your speed" window. Why should it then overwrite what is likely a valid resume.old file?
Firon Posted March 14, 2008 Report Posted March 14, 2008 It stores it on each update.When the current .dat is corrupted, it loads the .old. But if THAT is also corrupted, then you're boned.
rgutter Posted March 14, 2008 Author Report Posted March 14, 2008 Fair enough. (The program could ensure that it never renames .dat -> .old if the former is corrupt; that would ensure at least a valid backup, assuming it isn't kept open throughout program execution.) Thanks again. And oh yes, thanks for the program - easily my favourite torrent client.
jewelisheaven Posted March 14, 2008 Report Posted March 14, 2008 Here's the rub, ANY sort of verification when saving the resume means overhead. I've suggested something be done about this, but I can't think of any better way due to the sequence of actions which happen during the state-dump. That's why I backup uT religiously. Even an hourly backup of 4200 torrents takes up only something like 50 MiB a week.
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