Question about external drive on Synology NAS

[Enquiries]

I have a DS920+ with 4 8TB drives. I also have an external 6 TB hard drive connected via USB to it. The external hard drive is formatted as ext4. I use the Hyper Backup to back the NAS up the external hard drive every morning at 3 am.

My question is this, is the backup on the external drive accessible on a PC if the NAS suffers a catastrophic failure?

If so, how? I have 2 Windows PCs and a Linux Mint PC, if that helps.

[BobS]

I have a similar setup (DS920+ and USB hdd). Your question requires some clarification but the short answer is yes.  Download the desktop app "HyperBackupExplorer-3.0.1-0154-windows.zip" from the Synology Support page and install on your PC.  Once downloaded, unzip to a folder and then click on the HyperBackupExplorer.exe to run.  If your AV hits on a file named "img_worker.exe", allow it to be used which depends on your AV app.

Once you start the software, click on the "Browse Local Backup" and navigate >Network > Name of your DS920 > ubshare1 > Name HB File.hbk > which will then show a listing of Folders and the file named  "SynologyHyperBackup.bkpi" and open that file.

That opens the backup file and shows all the folders inside your nightly backup. From there you just navigate thru the folders to find the files you want to recover. Right-click on the file(s) and select Copy to and then navigate the thru the directory tree to copy it to your PC or wherever else you want it.

Edit: 22 Mar  Forgot to address the issue of not having a functional NAS.  In my case my USB drive is formatted in NTFS.  Using the same procedure above, connect the USB drive to your PC and navigate to the same folder and file to open the directories where your backups are stored. You may need to install a utility that allows Windows to open ext files. This one is from DiskInternals: https://www.diskinternals.com/linux-reader/.  Once installed on your PC, you can read the ext USB drive. There are other free utilities available that allow Windows to read Linux formats.

Now.. if you were looking to restore the nightly ABB backup images of your PC's that is a different process and you need to have a working NAS. Then you can restore the ABB files using the HyperBackup Restore function to access the USB drive HyperBackup file and restore it back to a working NAS. That has a few more steps than I can remember so consult the Synology Support pages for the details.  I've done it several times and it has worked but their instructions can be confusing in some articles...

BobS