I explained that I thought the power subject to brownouts, but they didn't believe me. They thought we weren't doing our jobs right even though all the rest of the computers had no issues. All their computers were working perfectly except a bank of three that kept needing a complete cleaning every two weeks. I had one client who moved a brand new building on the 8th floor. If you see this, then your data is at risk.Įveryone tells you the risk of spikes and it is something you need to account for, but brownouts are more subversive and can cause you no end of headaches. You see this from time to time when a light in a lamp might wink down and then wink back up. This is where the power has dipped but not enough for a blackout. But it might as well be Yosemite corrupting the drives.Ī lot of drives are damaged during brown out situations. I thought it was a rare corruption due to a power surge (although I use a UPS) or perhaps an incorrect disconnect/shut down. I really don't know what happened, but it seems quite worrying that two drives were lost at the same time, and that apparently I'm not the only one. I reused the other (Elements) drive for a Windows PC now and that seems to be OK so far. I bought an external HD from another manufacturer and stopped using WDs drives with Yosemite. I used it as a precaution in raid1 to store all my photos, but if the drives keep getting corrupted and TM stops working as well, then it's not a safe option any more. So now I'm no longer using the WD Mirror. I never had that installed myself though.

There were some issues with data loss on WD drives in Mavericks if you had the WD software installed. Only a reboot would help that (for a short while). After a reboot it seemed to work again, but then TM wouldn't back up the Mirror version any more at random times. I moved all the data and formatted them, but I had the same issue come back on the Mirror version! I had another popup that the disk was read-only and needed to be formatted. Once they appeared, the popup came back saying they needed to be formatted.

I could hear the disk 'rattling' (being accessed) for half an hour or so. It also took ages for them to appear after the reboot. They were sort of 'stuck' in repair mode in Disk Utility. The disks could only be mounted in read-only mode, as Yosemite said they couldn't be repaired and had to be formatted.Īfter trying a disk repair, I was only able to (un)mount the disks again by rebooting. Two WD HDs (one Mirror and one Elements) were suddenly corrupted. I had a similar issue recently, and it's a bit worrying.

File system check exit code is 8