ZFS Is it possible to browse a .zfs file in PCBSD 10.3?

P

Peter McKinley

Hi All,

I have a satnav type device which contains (when connected to a PC via USB), among other things in its internal storage, a 1GB file called navimap.zfs. I wish to know if this file can be browsed or opened in any way. I understand that zfs is a fully fledged file system and logical volume manager combined. I have read that the best way to work with zfs is to manipulate it in a zfs aware OS, so I have installed PCBSD 10.3 as I am not only a newbie when it comes to zfs but also command line operations, although I can cut and paste into a Terminal :)

I know I can't simply browse the file in Dolphin, it asks me what I want to open it with and when I select Find Files /Folders there are no results. The properties for this navimap.zfs file (which is in /media/da0/asimap/db) list the file type as "Unknown", despite the .zfs extension.

Please excuse my ignorance! I've trawled the web for anyone in a similar situation but to no avail.

Any suggestions?

Peter
 
I could be wrong, but I'll be highly surprised if that file is actually a ZFS pool or file system. A small device such as a satnav containing ZFS support seems dubious at best.
It's more likely just a coincidence that they chose that file extension.

You could try running file navimap.zfs and see if that is able to give any indication of what type of file it might be.
 
Are you sure it's ZFS? That would be an odd choice for a satnav filesystem IMHO. ZFS is not exactly lightweight. What device is it?

What's the output of hd -s 16k -n 112k /media/da0/asimap/db/navimap.zfs? ZFS puts a label on devices and that should display part of it.
 
It might be a file created from a zfs send mypool/dataset@snapshot > backup.zfs style command. In which case you may be able to use zfs receive to import it into a ZFS filesystem.

Oh wait, I didn't see it came from an existing device. In that case it's just a random three letter extension. It should also be noted that those three letter extensions really have no meaning anymore since the 8.3 filename days of MS-DOS.

https://en.wikipedia.org/wiki/8.3_filename
https://en.wikipedia.org/wiki/File_format#Magic_number
 
The ZFS storage stack creates no such files, and most certainly could not run on a low-powered embedded device.

Chances are there's no human-readable data there. I'd bet that what you're looking at is a file that almost certainly has no meaning to anyone but the device manufacturer. Probably ROM- or firmware-related. Probably something that should only be messed with if you don't value the product warranty or fear possible legal repurcussions. ;)
 
Thanks everyone for your highly knowledgeable responses! It didn't occur to me that the .zfs extension might be a smokescreen :)

I agree ANOKNUSA that the file is likely to contain the firmware for the device, at 1GB it is by far the largest file in a bunch of files only a few KB each. That's the part I'm interested in to see what information, if any, can be extracted. I'm not worried about warranty. I'm looking to replicate similar functionality but on a radically different platform. I'm looking for clues how this now discontinued device operated. Essentially it's a comparator between a stored map and a live NMEA stream.

usdmatt, output of file navimap.zfs gives
Code: 
navimap.zfs: dBase III DBT, version number 0, next free block index 793085736, 1st item ""
tobik, output of hd -s 16k -n 112k /media/MySpeed/asimap/db/navimap.zfs (for some reason the path changed when I reconnected....) is:
Code: 
00004000  a2 0d ff 86 ae a4 ff 86  b9 41 00 87 06 e1 00 87  |.........A......|
00004010  79 7b 01 87 da 20 02 87  0b bd 02 87 95 5a 03 87  |y{... .......Z..|
00004020  e4 02 04 87 6f a8 04 87  16 4c 05 87 93 ec 05 87  |....o....L......|
00004030  9b 88 06 87 c4 23 07 87  ab c2 07 87 c4 6b 08 87  |.....#.......k..|
00004040  61 0d 09 87 0f b1 09 87  b7 52 0a 87 b8 f3 0a 87  |a........R......|
00004050  cc 92 0b 87 6d 31 0c 87  c2 cc 0c 87 65 6d 0d 87  |....m1......em..|
00004060  c5 10 0e 87 6f af 0e 87  dc 4c 0f 87 0d ea 0f 87  |....o....L......|
00004070
SirDice perhaps unsurprisingly I couldn't get zfs receive to do anything useful:

Code: 
[peter@pcbsd-5384] /media/MySpeed/asimap/db% zfs receive
missing snapshot argument

[peter@pcbsd-5384] /media/MySpeed/asimap/db% zfs receive navimap
Error: Backup stream can not be read from a terminal.
You must redirect standard input.

[peter@pcbsd-5384] /media/MySpeed/asimap/db% zfs receive navimap.zfs
Error: Backup stream can not be read from a terminal.
You must redirect standard input.
Any further brain dump input will be greatly appreciated!

Peter
 
The output from file(1) shows it's most likely a dBase 3 file. As this file came from a navigation device I would guess it's a database that contains POI (Points-of-Interest) data, like gasstations, parking, etc.
 
Thanks SirDice, I tried simply changing the extension to .dbf in Windows but when I try to open it in DBF Manager I get an Invalid Header error message :(
 
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