Contents of an entire folder lost forever

[trumad]

Hi there,

BT sync is a nice piece of software, but it's inexplicably deleted the contents of an entire folder. I have no idea why. I guess I should take you through what I did, because I have no clue how to reproduce what happened. I certainly didn't delete the folder, on either drive.

1. use puresync to sync the hard drives initially on the same PC. It keeps timestamps on all files, but not on folders. weird.

2. install BT sync. connect backup hard drive to an offsite PC.

3. share the secret, pair the folders, allowing both to read/write/delete whatever.

4. opt not to use the syncarchive folder, because I had about 30GB free on the drives. My thinking was: what if I deleted 100GB from my primary HDD, and then copied another 100GB to it? The sync might fail, and that would create hassle. So I made the mistake of opting just to just put files in recycle bin.

5. Sync drive. Works fine for a few days, apart from some files that are "skipped due to bad timestamp". Those files seem unrelated - they haven't been deleted.

5.5 Noticed that lots of files are marked read-only. Changed their attributes on both hard drives, in case this was causing files to be skipped.

6. Deleted a 80GB folder from primary hard drive. Unrelated to the files that are missing.

6. Woke up this morning and notice I have an awful lot of free space on my HDD. around 300GB less than I thought. Can't figure out why - I had only deleted around 80GB the previous day.

7. Try to play some music and realise the files are gone. They're not in either recycle bin, on either PC. They are gone. around 300GB of music & music videos, that have taken me 8 years to collect.

I know you probably can't help me. But I would hope that this would help somebody else in the future to not lose their valuable data. Use syncarchive. Then again, perhaps bittorrent sync would still remove the files without using syncarchive, if this bug really is as serious as it seems to be?

I'll be happy to answer clarifying questions.

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[Varnagas]

.syncarchive folder

If it was deleted only on one node, it have to be moved into that folder. Unless you decided you will never need that and turned it off. Having in mind this is just alpha stage software, decision to disable archive is bad idea at all times. Look for it or have guts to blame yourself...

[GreatMarko]

Having in mind this is just alpha stage software...

Well, it's technically "beta" now... but the same principle applies - If you're syncing important/sensitive data using "beta" software you should always keep a backup!

However, as Varnaga says though, you should be able to find copies of your "lost" files in the hidden .syncarchive folder (enabled by default in Sync)

[Varnagas]

Well, it's technically "beta" now...

Thanks, my attitude towards sync needs as well it seems

[mdovey]

I've installed ZFS on a server running btsync, and scheduled regular snapshots. All the folders I'm sharing via btsync are shared with this server. That way if things go wrong I can roll back to a known good snapshot.

Matthew

[kos13]

I don't want to give a vague answer like - we are working on this, instead I'll elaborate on this topic.

1. Having P2P without dedicated server is really complex. If something bad happens on one device it might be propagated across devices;

2. .SyncArchive means you will never loose any data. It might be not convenient, but it definitely not a "lost forever"

3. We will work with trumad to get all possible information and figure out the issue

4. Surprisingly, there are a lot of cases when people blame Sync, but root cause was something different. Anyway we will find it out.

5. If you, by any chance, can supply us with logs it will help us tremendously.

kos

[trumad]

Yeah, I disabled syncarchive on both hard drives (which I admit was stupid) mostly because both hard drives were nearing their 1TB capacity, and I didn't have space to keep deleted files. The software seemed reasonably stable. Even kos13 believes that the software could never do this, and that the root cause is probably something different. But yes, in reply to Varnagas, I certainly do have the guts to blame myself. However, IF (even if it's a big if) the software DID cause this problem, I thought it might be helpful for you to find out why. I'm not running around blaming btsync for anything. I hope that has come across. Thanks. I'm sending private messages to Vadimt regarding this possible bug.

In terms of sending you logs, btsync only seems to keep logs from the current instance. My computer was shut down at least once before I noticed the problem, and the log from the previous night was overwritten. Was it? Am I wrong? Does BTsync keep all its logs?

[dswd]

Hey trumad,

have you checked for filesystem problems?

If you had a filesystem error on one of you machines that could result in that directory being lost and btsync could then misdetect that as a delete operation and sync that to the other machines.

If you have Linux you might want to do an fsck and look at the lost+found directories (though I doubt you will find it there as you got lots of free space).

Also you could use foremost (http://wiki.ubuntuusers.de/foremost) on your block device to rescue the mp3 files (and maybe videos) if they have not been overwritten since. At least you have multiple chances per file, one for each synced machine.

[Varnagas]

trumad,

I admire your dignity and feel sorry for your lost files. I hope you a find a way to restore them or a positivism to recollect them and keep them in a smarter way.

Been there few times myself. Always my fault. Took a lesson or a few. Do not get too attached to things. And files you can not afford to lose keep tight in size and wide in backups.

[trumad]

Well yeah, thankfully I had all the files backed up on mega.co.nz. However, they were in mp3 format, not the lossless flac format. But I can live with that I backed them all up there only a few months ago, on a whim. Thank goodness! I can't tell you what hassle it has been trying to download them from mega though! Thanks for the nice messages

[trumad]

oh - RE: a file system error. Could that really remove/affect an entire folder in isolation? Wouldn't that just affect a bunch of random files across the hard drive?

[dswd]

@trumad

It could of course. When a single directory entry has an error all child elements would be without father and depending on filesystem on OS would either be lost or moved to lost+found. Either way btsync would see that as files being deleted.

But that is only a guess. If you never had any problems on your disks and you didn't reboot any node, it is more likely that btsync has a bug.