Poor man's NAS


A Network Attached Storage(NAS) has been in my wanted list for quite a long time, thanks to Live Search Cashback program to make it happen: a Western Digital MyBook World Edition(500GB). More information about the hardware specification:

  • ARM926EJ-Sid(wb) [41069265] revision 5 (ARMv5TEJ) 99.73 MHz
  • Memory: 32M
  • VIA Networking Velocity Family Gigabit Ethernet
  • WD5000AAVS-0 500G HD

I believe 100MHz ARM CPU is powerful enough to drive this tiny box, but the limited capacity of memory cripples it as a lame duck. The sustainable file write(85G using lftp mirror) rate is approximately 3.8MB/s. It hardly qualifies any service beyond file server. Now, it is time to hack.

Jailbreak and SSH

The first thing to do is to create a user in the web interface of MyBook as root with null password is banned for security reason. Log on with admin and 123456, create a user JOE and setup the password for later use. Run the script discussed in the wiki, and ssh with JOE. Now you can su to root with blank password, 0wned!

User management

MyBook takes a very intricate way to manage users:

All Samba users are granted shell access, but unix password sync = yes is not set, the /etc/shadow and /var/private/smbpasswd are updated individually by a Perl script via the web interface. The only reasonable explanation is the minimized Samba lacks PAM support.

All user names are capitalized. I assume this is a brutal force approach to address the difference between Samba and Linux native accounts: Windows user name is case insensitive, while Linux is case-sensitive.

As the password scrambled in /etc/shadow, it is easier to add/delete/update users via the web interface, then fine-tune the corresponding files. The user administration executives are hidden in /usr/www/nbin

Share with Samba

The default exported directory is /share/internal/PUBLIC, the permission of the directory is set as rwsr-sr-x, and the owner is www-data, YMMV. So any file/directory created will be owned by www-data.

remember to change the default mask in /etc/smb.conf:

create mask = 0775
directory mask = 0775

Package management

Though I am a big fan of Gentoo, it is a little bit paranoid to build everything from scratch. A precompiled package management, like Optware makes more sense. Check out this tutorial for bootstrapping.

The essential packages for daily administration imho are screen, lftp.

Feature requests

There are some itchy miss features, if you happen to know a solution or hint, please drop me a message in the comment:

Access Anywhere No mionet, just SSH. If you are a perfectionist, consider to port this Delphi application to MyBook to host MyBook in your preferred domain.

Download Manager A web front-end to listen to download requests from Firefox/IE plugins, then delegate it to wget backend with cookie support. A more aggressive approach may support megaupload happy hour.