"OS X can't repare your disk" big bug

Hello everyone,

I store a lot of data, essentially photographs and videos on my Drobo (Gen 2) FW800.
I sort my files by projects going from Project 1 to 30. I just plugged back my Drobo today, and found out that my projects 18 to 24 just disappeared.
By that I mean, the folders 18, 19, 20… are there but empty. When I check infos, it says 0 ko inside folder.

When I turn the Drobo on, I get an error message from Mac saying: “OS X can’t repare your disk”.
I tried to do a Disk utility run, but it crashed and said: “utility disk can’t repare your drive, save as much as you can, format and restore”.

What I don’t understand is that my Drobo seems to work fine. All drives lights are Green. I received no Alert, and my drobo dashboard says: your drives are fine, everything works fine ?
Thanks to god I didn’t trust my Drobo and have another copy of all data on classical hard-drives. But still this freaks me out !
Can somebody with more knowledge than me help me understand ?

I use my Drobo with a MacBook Pro, under oSX 10.9.2. with 4 Barracuda hard drives of 3 To.

Drobo doesn’t know anything about the integrity of the filesystem that is stored on the volumes.

That’s what Disk Utility, DiskWarrior, etc…are for.

I am also slightly wary of long-term storage on disks due to ‘Bit Rot’ (http://en.wikipedia.org/wiki/Data_degradation).

The newer Drobo’s combat this problem with ‘data scrubbing’ (http://en.wikipedia.org/wiki/Data_scrubbing).

I run Disk Utility on my Drobo’s (5D and Gen2) once a month.

Hi, thanks for your answer, I didn’t know about that.
But you think that just because of “data scrubbing” I could lose 6 consecutive entire folders, containing hundreds of photos and videos, about 1000/1500 Go ?

That would be crazy. I have my drobo for a little more than a year now, and never had this issue for years with classical external hard drives, with the same files and everything.
What do you suggest I can do ?

Thanks again.

I didn’t mean to imply that bit rot was responsible for your missing files. Just that it is an issue to be aware of over time.

I do think ‘preventative’ maintenance on a filesystem becomes more important as you increase the complexity of the device that is hosting your filesystem.

There are some things you should never do to a Drobo: create partitions/volumes outside of Dashboard, run any kind of ‘defrag’ tool, or use any program/utility that is trying to access a specific, physical sector on a disk. All of those will make ‘very bad things’ happen to your Drobo.

Do you have DiskWarrior or another disk utility? I have had luck with other tools when Apple’s Disk Utility can’t fix it.

Thanks for your message !
DiskWarrior worked impressively and rebuilt every lost files. Much stronger than the Disk utility available with Mac.

I am still a little afraid of my Drobo losing files without error alert now, but thanks for your help !

well done mgriffin, and simon for having an extra backup just in case :slight_smile: