Q:

photorec photo recovery software not seeing my mounted filesystem - trying to use photorec to recover lost jpegs

What is my situation?
I am working in a Dev Ops capacity for a service that manages jpeg files online. We had an unfortunate deploy and our media files (jpegs) are completely gone. I anticipate that our loss is probably simple and may be recoverable. I think somehow that the directory that contains the sub-directories that have our jpeg files was unlinked. If this is the case, we should be able to recover them.
What I have done so far and where we are hosted -- details
I realized the loss almost right away and fortunately we did not have any users online at that moment. I stopped our service and brought down our server. I did that to prevent any more writes to the filesystem figuring that avoiding writes was essential to file recovery.
We are running Ubuntu 16.04 in DigitalOcean. I have brought the server back up using DigitalOcean's recovery mode. This permits one to mount the filesystem of the given virtual host without running the virtual host and without running the services one has on the virtual host. This should be sufficient and correct for performing any form of recovery.
I need some where to write data for recovery. To that end, I have another server in DigitalOcean in the same data center (SFO1 unfortunately). I have mounted that host's filesystem using sshfs. I should be able to write any recovery data from my virtual host's filesystem (which is in recovery mode) to this other host via sshfs.
I selected the following utility to execute my recovery: PhotoRec
That utility is actually two utilities -- PhotoRec and TestDisk.
The filesystem of the host we wish to recover is ext4. PhotoRec supports ext4. TestDisk may not support ext4. That's okay, according to the documentation if the data is still there and largely uncorrupted, then we should be able to recover it with PhotoRec.
Here is the output of when I run df -Th -- as you can see the filesystem I wish to recover is /dev/vda1 it is of type ext4 and mounted via /mnt .  I installed photorec in /lib/live/mount/overlay which is the tmpfs . I have mounted another host via sshfs within the same datacenter to put any recovered data on:
root@xxxx-xxxxxx-xxxxxxxxx:~# df -Th
Filesystem             Type        Size  Used Avail Use% Mounted on
udev                   devtmpfs    7.9G     0  7.9G   0% /dev
tmpfs                  tmpfs       1.6G  6.2M  1.6G   1% /run
/dev/sr0               iso9660     251M  251M     0 100% /lib/live/mount/medium
/dev/loop0             squashfs    220M  220M     0 100% /lib/live/mount/rootfs/rescue_rootfs.squashfs
tmpfs                  tmpfs       7.9G   14M  7.9G   1% /lib/live/mount/overlay
overlay                overlay     7.9G   78M  7.8G   1% /
tmpfs                  tmpfs       7.9G     0  7.9G   0% /dev/shm
tmpfs                  tmpfs       5.0M     0  5.0M   0% /run/lock
tmpfs                  tmpfs       7.9G     0  7.9G   0% /sys/fs/cgroup
tmpfs                  tmpfs       1.6G     0  1.6G   0% /run/user/0
root@xxx.xxx.xxx.xxx:/ fuse.sshfs  311G   13G  298G   5% /mnt2/xxxxxx-xxxxxx-xxxxxx
/dev/vda1              ext4        311G   41G  270G  14% /mnt

When I run photorec it only sees:
>Disk /dev/sr0 - 252 MB / 250 MiB (RO) - QEMU DVD-ROM

It does not see my filesystem that I want to execute recovery on at all. That is:
/dev/vda1              ext4        311G   41G  270G  14% /mnt

I have tried this with my filesystem mounted because that seems right to me. However, we did find in some online documentation that some file recovery tools require file systems to not be mounted (which seems weird to me - how is that supposed to work). So I tried executing it unmounted but same thing: it only sees:
>Disk /dev/sr0 - 252 MB / 250 MiB (RO) - QEMU DVD-ROM

Does anyone have any suggestions regarding getting photorec to see my filesystem:
/dev/vda1              ext4        311G   41G  270G  14% /mnt

I do have some backups, but unfortunately, I have about seven days worth of unbacked up photos. We could in theory live without them and reach out to our clients and get data from them and reprocess and repost it. But it would be ideal, if I could with just a few clicks of some buttons, get back this data that is likely still un the filesystem just unreachable.
Help using photorec for this purpose wouold be ideal as would any other suggestions regarding how to recover my lost/missing files.
Thanks!

A:

You can tell photorec explicitly which block device to work with, e.g. photorec /dev/vda1. It must not be mounted.
Of course, before photorec, you should try using extundelete, which may undelete your files on an ext* filesystem more quickly. Again, it must not be mounted.
And of course you should be prepared to go to your backup.

