Areca file corruption issue

Hi,

I have an issue with an Areca-1882IX running in a MacPro5,1 w/ OS X 10.10.5.
I have a single 30TB RAID-5 volume made up of various drive types. The volume contains images and videos. When I browse the volume, the image/video previews show a corrupted version of the image, but when I open the file, the corruption changes. Indicating to me, that there's an error in reading the file, and hopefully, the file is still intact on the drive. This happens for every file on the drive.

I recently upgraded the Areca firmware to 1.52.
The 16 spindles are various Seagate SATA drives.

I'm hoping this is a settings/driver issue, but I don't know where to start. I've uploaded screenshots of this issue along with my Areca settings to this album: http://imgur.com/a/Iwams

Any pointers or ideas are appreciated.

When you say that the corruption "changes" when you open the file, do you mean it is still corrupted but just different than the preview each time? Please post a complete log from the card. Just FYI, a 16 spindle 30TB RAID5 is just inviting disaster, once you resolve what is going on you should immediately migrate to RAID6! What filesystem is the array? Are you running the latest drivers? When did this problem manifest itself? If you copy over a known good file and immediately open it, is it corrupted immediately?

Yes, that's correct. The image is still distorted, but the way Finder distorts the image is different from how Adobe Elements distorts the image. Some files Elements can't open as it claims it does not support the file type, indicating the file header cannot be read correctly.

The complete log is here: http://pastebin.com/gC5PU3zb

I started noticing these fragmentations during the first week of August. I updated the firmware on the Areca card after that.

I just copied a new, clean, video file to the volume, and it did not show the fragmentation that existing files show.

I agree that RAID-5 is not optimal for this setup. We will look into improving it as soon as we can put this problem behind us and we can find another 30TB of space to store this stuff temporarily while we change the setup.

First question, what type of enclosure are these drives mounted in? Do you have historical backups of this array from a known-good state? Did you realize of the 16 drives, you have 10 3TB and 6 2TB (essentially wasting 10TB of space on the 3TB drives (R5 will only use the lowest common denominator in drive size in a particular array). From the log, it seems you have either a failure of the cable(s) connecting the card to the enclosure, or of the enclosure itself. In 3 separate incidents in the time covered by the log, you lost connection to the array (of some or all of the drives, as well as failing drives in slots 4 & 7)

Unfortunately, based upon your log, I am the bearer of some bad news. From what I am reading, you have an activated failed volume. My suggestion at this point is to contact Areca (and also try to find Jus here or on 2CPU), but based on what you have posted and the fact that the volume is dynamically unstable I am not optimistic of any of the data on that array.

They are mounted in two of these: http://www.pc-pitstop.com/sata_enclosures/scsat84xb.asp. The arrays are connected directly to the Areca using mini-SAS to SATA fanout cables. The connections are awkward.

We have a second, identical array, to which this data is backed up. However, this second array had two drives fail. The second one failed after I replaced the first before the rebuild could complete. I've shut that system down completely.
We moved, and these drives did not handle the move well.

The plan is, if we can recover the data, to move to a http://www.pc-pitstop.com/sas_cables_enclosures/scsase166gv2.asp with 6TB drives, but it looks like we'll have to put that off a little since all the $ will be going to paying someone to recover either of these arrays. Can you recommend a service for attempting this?

What do you mean by this: "and also try to find Jus here or on 2CPU"?

How important is this data? Is it business make-or-break? If your backup is also failed (which it seems to be based on your description) you are in a precarious situation. If you go for professional recovery, you are looking at many thousands of dollars. I would recommend Drivesavers for professional work, but it will NOT be cheap. While it can be an expensive lesson, remember RAID is NOT a backup, and that a single live backup is not a good enough solution for critical business data. Imagine if you had been backing up all along good data, once you had the corruption and completed the backup you would have overwritten all your good data with bad (depending on your backup method, but generally with a identical array you are doing live syncs and not incremental backups). Tape backup is the most economical for multi-generation backups and will also allow you to maintain incremental, historical backups which wouldn't be just overwritten with a bad backup.

Jus is another user here.