Disk became empty after SSD accidentally unplugged

[eleked]

Hi, I've setup a SSD as cache for one of my HDD that has 3 partitions on it, and been using for few months.
This afternoon, I decided to do some maintenance on my PC (cleaning, replace thermal paste), after completed, I boot up my PC and realize partitions of that HDD disk are not there.
When I check with Disk Management, that disk has became a empty disk, which has no partition at all.
I shut down the PC, do the checking, and realize SATA connection to SSD actually loosen, so I replug it and boot up my PC again.
However it doesn't give back my partitions, Disk Management still shows empty disk, and primocache GUI shows like this:


And here's how disk management looks like (I masked out DISK that is working and non-related):

DISK 1 is the SSD and Disk 4 is the HDD, they were tied for primocache.

I haven't try to do any format/repartition, as I afraid that will cause my data lost forever.
Can anyone gives clue on what should I do to reclaim my partition?
Thanks.

[InquiringMind]

Ouch! Sorry to hear about this, but your best solution may be to restore from a backup (and for anyone without backups, take this as a message on why they're necessary).

I'd guess that your HDD partition table has become corrupted (maybe as a result of Windows trying to "fix" what it may have seen as a faulty disk following the SSD disconnection) given that you have multiple partitions showing without size details.

I don't know of any recovery/reconciliation feature in PrimoCache to handle this (and none of the command line options seem to offer anything) but if you really want to recover your data my suggestion would be:

• avoid using the HDD/SSD from now on, since any action you take (even just starting Windows) will overwrite more data - use a backup system or setup a new installation on another HDD;
• wait for a response from support to see if there are any data recovery features for L2 caching.

If you have no backups and cannot wait for an official reply then I would try Stopping the cache (which *may* flush L2 data back to HDD) and using a file recovery tool on the HDD to copy the most important data (documents, application data) to another volume (USB stick or whatever) and setting up a fresh install on a new HDD.

Even if a fix is offered which appears to work, I'd recommend going for a fresh install since it would be next to impossible to guarantee recovery of all data in your situation.

[Bjameson]

If I understand this correctly, the HDD partition table was found to have disappeared after maintenance. Only later was the faulty SSD connector discovered. The SSD was probably used as L2. To me it seems this has nothing to do with Primocache so it is unlikely that Romex can help you.

I've seen many computers dropping disk partition tables. Cause unknown but in one clear case (older ASUS mobo) I have proof that the BIOS is buggy and randomly zaps the partition table. If this is the case, it can be repaired without data loss.

Download the Aomei Partition Assistant (freeware, works great for me) from http://www.disk-partition.com/download-home.html and install it on you boot disk (not on the faulty one).

- From the Aomei Wizard menu, select Partition Recovery Wizard. Highlight (single left-click) the disk you want to repair and click Next.
- Select Fast search. If it finds no partitions, try Full search. If Full search finds nothing: panic.
- After scanning it will show a list of the partitions it found. Some may be ghosts so try to guess which ones you need to recover and select those.
- Click Proceed and the selected partitions will be instantly recovered. It does so by rebuilding the partition table.

I found that recovering one partition at a time gives better and faster results. Start by recovering the first partition and repeat the same procedure until you have all lost partitions back.

Run a full chkdsk /f on all recovered partitions. Afterwards you can use Primocache to re-assign the SSD to L2 cache for the HDD.
Should Aomei fail, use Google to find other repair tools. In essence they all do the same thing: scan an rebuild the partition table.

To prevent further mishaps you can download a terrific free-for-personal-use image backup tool from http://www.macrium.com/reflectfree.aspx. Macrium Reflect allows you to backup/restore a complete image of a disk to/from a backup medium. It also allows you to burn a bootable rescue CD. It saved my ass numerous times.

Good luck and let us know how things work out.

[eleked]

Thanks for replying and those helpful ideas. I appreciate them.
Unfortunately I don't have any backup for the files inside the disk, so, lesson learned!

>>InquiringMind
I am guessing the same, which is partition table is somehow wiped/corrupted, but I cannot confirm this is the reason.
I am thinking to clone the whole disk into another disk, and try to recover the files with some data recovery tools to see what I can recover.

>>Bjameson
Thanks for providing idea on how to recover the partition.
Unfortunately, I've tried with Aomei Partition Assistant and TestDisk, both return no partition found even with detailed scan (scanned 4 times, 2 simple scan and 2 detailed scan). I just tried to rescan the disk with the disk attached to that cache task in PrimoCache, but the result is same. So I guess the disk is somehow not recognized as proper disk.

[InquiringMind]

Thanks for the update and sorry to hear that the worst case seems to have been confirmed. It may be worth trying Clonezilla Live (booting from DVD or USB) to create a copy of the problem HDD for further experimentation and using WinHex and similar tools to see what can then be retrieved.

[Bjameson]

I'm also sorry that it didn't work out. What puzzles me is how the partition boundaries outside the partition table could have disappeared. The advanced scan should have found those, regardless of the zapped partition table. I agree with InquiringMind, only experiment on an image that you can restore again and again.

Good luck,

[Davey126]

Depending on the importance of the data you may want to give SpinRite a try. This is an old DOS based utility but one that has saved my bacon on more than a few occasions. It works at a very low level and can usually recover data/partitions that escape other tools. The HUGE catch is there is no trial/free version so you must purchase a copy even for a single use. The author offers a 30-day 'no questions asked' guarantee which he will honor if the software does not perform to your expectations. That said, nothing can recover data that has been over written and $90 is a big chuck of change for a tool you may only use once. Just presenting another option - not endorsing SpinRite or any other product for that matter. Best wishes.

https://www.grc.com/sr/spinrite.htm
https://www.grc.com/sr/faq.htm -> this section covers 'money back' guarantee.

[Bjameson]

I've used SpinRite in the past and it worked very well. However, it was designed to read/repair disks suffering from flakey magnetic surfaces or head misalignements. The disk in question appears to have been zapped, not physically damaged.

If the advanced scan of the other utilities completed without errors (other than not finding partitions) then I'd advise to first explore free alternatives before forking out $89,00. Of course SpinRite is an option but I think Eleked needs no further disappointments at this time.

[Davey126]

Yup - agree with going with the free alternatives before moving to paid/commercial offerings which offers no guarantees on data recovery (other than money back on the tool referenced above). I also agree with Bjameson's observations on what may have happened to the media in question. Tough situation that ultimately may not have a solution.

[Support]

I'm really sorry for this worst case! PrimoCache doesn't save write-data to level-2 cache, this means that any data written to HDD wounldn't be saved to SSD. I think the problem might be caused by the following reason.
a) During the maintaince, some data might need to be relocated. Data was read from SSD cache before relocation. However, as SSD connection was loosen, read process might succeed but data was incorrect (If read process is not successful, PrimoCache will try to read data from HDD instead of SSD cache). Then this incorrect data was relocated to another position in the HDD, leading to problems.
b) Another possibility is that this issue was caused by maintaince software or HDD/motherboard hardware errors.

I agree with InquiringMind and Bjameson, you may need to make an image of the source HDD first.