Unable to mount drive OSX10.10

My Drobo has always worked since day 1. It’s configured with 4 x 2TB drives in a Raid 5. It has been backing up my Mac via FireWire for many months.

I just got back from vacation, plugged in my Mac as usual, and my Drobo won’t mount.

I can see the drive in Disk Utility however I cannot mount the drive. Disk Utility tells me “File system check exit code is 8”.

Drobo dashboard tells me everything is fine.

What should I do to repair the drive so it mounts properly. I don’t want to lose my data.

If there is an option for repair, you should go ahead and click on it.

This needs to be done, else there is no way you could access your data.
Unless, you wouldn’t mind using software like Data Rescue, what it does is it bypasses the file system and attempt to extract your files.