Daten gelöscht

NSA210, NSA221, NSA310, NSA310a, NSA310S, NSA320, NSA320S, NSA325, NSA325-v2
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hilmi
Posts: 3
Joined: Fri 11. Jan 2019, 23:31

Daten gelöscht

Post by hilmi »

Hallo Leute,
hab mit größter Wahrscheinlichkeit den größten Blödsinn der 20 Jahre gemacht.
Hab ein Zyxel 325v2 mit nur einer Festplatte.
Hatte zwei NFS-Freigaben eingerichtet. Eine davon gelöscht.
Nun sind alle Daten weg.
Kann mich langsam erinnern , das man genau das nicht macht.

Gibt es aber trotzdem eine Möglichkeit diese Daten zu retten.
Zur Not auch von Profis.
Oder sind die Daten wirklich physisch nicht mehr auf der Platte

Waren meine Mediendaten der letzten 10 Jahre. Filme ,Fotos etc.
Könnte vor Wut (über meine Blödheit) heulen. :oops:

Bin über jeden Tipp dankbar
Mijzelf
Posts: 48
Joined: Wed 14. Nov 2018, 19:50

Re: Daten gelöscht

Post by Mijzelf »

When I recall correctly, an NFS share on a 325 is a subdirectory in /i-data/md0/nfs/. Deleting a share deletes the subdirectory on disk.

The bad news is that there is no 'undelete' on the NAS. The good news is that the data is not actually wiped from the disk, deletion is only administrative. But the sectors are marked as unused, and can be re-used at any moment. So if you want to recover, switch off the NAS immediately.

There are 2 ways to recover the data. (as far as it's still on the disk). The data volume has an ext3 filesystem. You can try extundelete to recover the files. For that you need to connect the disk to a Linux computer, assemble the raid array (a single disk volume on a zyxel is also in a raid array) and follow the instructions on the page.

The other way is low-level recovery. A program like PhotoRec can search the surface of the disk for recognizable files, by looking at known headers, and restore them. In order to do so the file needs an recognizable header, so for instance flat text files can't be found this way, and the files may not be fragmented, as there is no help from the filesystem to connect the fragments.
Fortunately most media files have a good header, and fragmentation on a Linux NAS is low, as long as the disk is not almost full.
As low-level recovery works without help of the filesystem, you don't need an OS which 'knows' the filesystem, so any OS supported by the tool is sufficient.

A big drawback of low-level recovery is that it recovers files, not the metadata, as the metadata is stored in the filesystem. The metadata here is filename (including subdirectories) and timestamps. Another one is that you might restore corrupted or bogus files, without knowing it.

When you want to use extundelete it's a good practise to create a bit-by-bit copy of the disk first, using dd, or something like that. Any write done to the filesystem can corrupt or erase a file.
hilmi
Posts: 3
Joined: Fri 11. Jan 2019, 23:31

Re: Daten gelöscht

Post by hilmi »

Danke für diese vielen Tipps.
Das wird natürlich alles dauern.
Melde mich auf jeden Fall wieder und berichte.
MechaNic
Posts: 1
Joined: Wed 23. Jan 2019, 14:17

Re: Daten gelöscht

Post by MechaNic »

I also thank for the tip. :P :P
The other way is low-level recovery. A program like PhotoRec can search the surface of the disk for recognizable files, by looking at known headers, and restore them. In order to do so the file needs an recognizable header, so for instance flat text files can't be found this way, and the files may not be fragmented, as there is no help from the filesystem to connect the fragments.
Fortunately most media files have a good header, and fragmentation on a Linux NAS is low, as long as the disk is not almost full.
As low-level recovery works without help of the filesystem, you don't need an OS which 'knows' the filesystem, so any OS supported by the tool is sufficient.

I used Photorec to recover deleted files from my NSA325 by removing one of the two HDD's and connecting it to my PC via a SATA to USB adapter. It took some 10 hours, but it worked. It recognised MP4 files.

Nic
hilmi
Posts: 3
Joined: Fri 11. Jan 2019, 23:31

Re: Daten gelöscht

Post by hilmi »

Hat nicht zu 100% funktioniert.
Konnte aber einen grossen Teil der Daten mit R-Linux zurück holen.


PS: wieso ist das Forum so in den Tiefen des Netz verschwunden.
Was ist mit dem Forum "Zyxelforum.de" geworden.
Weiß da jemand mehr.
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shv
Posts: 30
Joined: Sat 10. Nov 2018, 17:36

Re: Daten gelöscht

Post by shv »

hilmi wrote: PS: wieso ist das Forum so in den Tiefen des Netz verschwunden.
Was ist mit dem Forum "Zyxelforum.de" geworden.
Weiß da jemand mehr.
http://pogoplug.bplaced.net/zyxelforum/ ... 7&p=51#p51
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