Note that the information given here, simply reports my experience with the mv5020. I have no experience with other models of HP MediaVault than the mv5020.
I provide no warranty, and you should proceed at your own risk. A risk, which is true and real - as stated below.
Following these instructions is likely to void any warranty on the HP MediaVault.
Following these instructions are highly likely make your HP MediaVault completely and utterly unresponsive and cause loss of data. This is known as "bricking" the MediaVault.
If (or when) this happens to you, there are three things you can do:
Unfortunately, the recovery-utility will reset the contents of the disks to factory default: Empty.
In other words: The recovery-utility WILL WIPE ALL YOUR FILES FROM THE MediaVault DISK(S).
Lee Devlin has located a version of the image, which should be able to restore the firmware without cleaning the disks, but I have not yet heard of anyone using it. You can find the instructions and the modified image here.
Another warning: When I had the opportunity to try out the recovery tool, it failed in varying ways 9 out of 10 times - and each attempt took at least 30 minutes. However, don't give up: Suddenly, randomly, the blue light turns on, and you are up-and-running again - time to restore your backup of your disk contents (which you have - right?).
|/||Root directory - this is where you are at login|
|/bin||Linux executables directory.|
|/usr/bin||More Linux executables.|
|/usr/htdocs||The root directory for the Apache webserver. This is where web-pages are served from - except JSPs.|
|/usr/jetty-5.1.12/webapps/Webshare||This is where JSP pages are located. This is for experts only, so if you don't already know your way around a J2EE directory structure, stay away from this place.|
|/etc||Standard Linux configuration files. Your Apache webserver httpd.conf file is here, but it will be overwritten at boot-up.|
|/etc/inc||MediaVault boot-scripts. These are very fragile, so handle with care. Any mistake, and you have a "brick". You will, however, be hacking the file func_httpd.inc and possibly also func_daemon.inc and func_webshare.inc|
|/share||MediaVault disk(s). The above directories are all on the firmware file-system, whereas the /share directories are on the real hard-drive(s).|
|/share/1000||Here you find the virtual disks (Samba mount-points): Documents, Backup, etc. that you can see from Windows.|
|/share/1000/Documents||The mv5020 does not sport an ftp server, so create a directory here for file-transfers between Windows and MV.|
|/share/1000/Documents/web||This is what I happened to call my transfer directory. You could also create and mount a new shared directory using the standard GUI for the MediaVault|
|/share/1000/postgres||This is where the PostgreSQL database resides. It is not mounted on Samba. I don't think you can, and I wouldn't like to try.|
|/share/1000/postgres/data||If you need access to the PostgreSQL database on the MediaVault from Windows, you need to customize the pg_hba.conf file here.|
You can do that directly on the MediaVault using the vi-editor. It works if you have the terminal settings right, and if you fixed the TTY bug as explained above.
Personally, I am not fond of vi, so if you are like me, you may want to transfer the file to Windows, edit it there, and then move it back to the original location. However, you must take care, because there is a subtle difference between text-files on Linux and Windows.
On Windows, all lines must end with two characters (bytes) named CR and LF, whereas on Linux, lines must end in the CR byte only.
(Aside: CR means CarriageReturn, and LF means LineFeed. When I was a kid, the Teletype terminals were basically remote-controlled typewriters. Moving the type-head back to the beginning of the line was a CR operation, whereas advancing the paper by one line was a LF operation. Doing just the LF was good fun - you could create all sorts of interesting effects by typing several lines on top of eachother).
Some Windows tools, such as Wordpad (C:\Program Files\Windows NT\Accessories\wordpad.exe) can interpret Linux files correctly, but will write files back containing CR-LF sequences. Other Windows tools, such as Notepad cannot correcly display Linux files.
Conversely, some Linux tools can interpret Windows files correctly, whereas others will fail due to the unexpected LF characters inserted by Windows tools.
So this is what you do, if you want to edit a file from the MediaVault from Windows: