So, I have a Linux machine with tons of HDD storage space (250 + 500 GB) .  The XP machine needs additional space.  And it must be transparent to the rest of the family.  I used Samba to create file shares on the Linux machine, then created mapped network drives on the XP machine that connect automatically to the Linux machine’s HDDs at login.  It wasn’t hard, but did trip me up on a couple points.

Samba is an open source software package that allows Linux/Unix machines to participate in Windows networking as nodes in the Windows “Network Neighborhood” and therefore provide file sharing between Linux and Windows machines.  It was easy to install the Samba package on CentOS, using the Add/Remove software package from the desktop GUI, and included a GUI configuration tool for Samba.  The CentOS deployment guide provides good guidance for configuration, and the samba.org site provide an excellent extra level of detail for the software.  A couple of points to add that were key learnings for me:

1. The Samba GUI provides a simple, easy configuration tool for the basic samba config, identifying the workgroup name, shared volumes and users/passwords.  The manual config is accomplished via the smb.conf file in /etc/samba.  Manual edit of the conf file provides more options than the GUI, including logging level, source IP address filtering, and preventing access to home directory.  However, if you make changes to this conf file, then make changes to the config via the GUI, your manual changes to the conf file will be removed.  So make the simple GUI config changes first, get a functioning system, then tweak the configuration with vi edits of the smb.conf file.
2. Windows XP required that I set samba up with “user” authentication, not “share”, and I had to encrypt the passwords on the Samba config.  Windows would not attempt to make connections when Samba was configured with unencrypted passwords.

The Samba config was easier to config than the Windows XP side.  Once I had the Samba server running, I was able to go into “Network Neighborhood”, view the “workgroup nodes” and connect with the user/password set up in Samba.  Then I could map a drive letter to a share folder on the Linux box.  Easy, right?  Almost.  Even though I asked Windows to ‘reconnect at login’, Windows could not.  Looking at the Samba logs in var/log/samba/smbd.log (with logging set to level 3 via the conf file “log level = 3) I could tell that the problem was with XP, not Samba, and I suspect that Windows was not chaching the password.

The solution was a batch file that runs at startup on the XP machine.  I found a forum post that explained the syntax very well, using the net use command.  My specific command was “net use S: \\server\storage passwd /USER:username”  Then I just had to store the batch file in the ‘startup’ programs folder for “All Users”, and now the drive maps automatically at startup.  Then I’ll convert the “My Pictures” folder to a shortcut to a folder on the Samba shared volume.  Perfectly transparent to my family.

As long as the power is on the Linux box.

Update Jul 20, 2009:

I rebuilt my machine and used a firewall and Security Enhanced Linux (SELinux), which created a couple additional challenges.  First, the firewall had to be configured to allow smb protocol for Samba, which was easy.  Second, (and a bit more tricky) the smb.conf file had notes for SELinux, indicating that the shared folders needed to be marked with “samba_share_t”. The current labels can be displayed with “ls -ldZ /path”, and the label on a share folder can be set with “chcon -t samba_share_t /path”. Once I resolved these issues, all was fine.

Photo credit, eheçatzin

I worked with my friend Chris (computer aficionado) to assemble a list of components from newegg.  I wanted to build a cheap machine, but still have enough power to allow me to experiment with LAMP infrastructure and virtualization, and also enough storage to archive the family’s growing collection of digital photos and video.

Here is what we chose for hardware:

• GIGABYTE GZ-X5BPD-500 Black SECC Steel / ABS ATX Mid Tower Computer Case –Model #:GZ-X5BPD-500
• ASUS M3N78-EM AM2+/AM2 NVIDIA GeForce 8300 HDMI Micro ATX AMD Motherboard – Model M3N78-EM
  
• Thermaltake Purepower W0100RU 500W ATX 12V 2.0 Power Supply – Model #:W0100RU
• AMD Athlon 64 X2 4400+ Brisbane 2.3GHz Socket AM2 Dual-Core Processor –Model ADO4400IAA5DU
• Kingston 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model KVR800D2N6K2/4G – Model #:KVR800D2N6K2/4G
• Seagate Barracuda 7200.10 ST3250410AS 250GB 7200 RPM SATA 3.0Gb/s 3.5″ Internal Hard Drive – Model #:ST3250410AS
• SAMSUNG 22X DVD Burner Black SATA – Model SH-S223F
• And a Thermaltake CPU cooler, TR2-R1 P/N A4022 (more about this later).
  

All said and done, minus rebates and including shipping, about 380  bucks.

I ordered the gear on Sunday morning, and received the shipment Thursday afternoon.  My son and I split the assembly pretty evenly, while my daughter even helped mount the HDD.  I won’t review the steps I took to build it, you can find that info many places on the web, such as here, here and here.  For the sake of transparency, I will mention the two mistakes that I made while building it:

1. I mistakenly bought a CPU without a cooling fan.  Dumb. I had the correct CPU picked out, then at the last minute saw a cheaper/nearly identical version, and quickly picked it, not paying attention to the details (or the picture, clearly showing a CPU only).  Impact? Since I didn’t want to wait for the delivery of a fan, or attempt to exchange the CPU, I went out to CompUSA/TigerDirect and picked up a $23 Thermaltake CPU cooler and some thermal paste (more than I ‘saved’ on my last-minute CPU choice).
2. Despite very good and very clear instructions from ASUS, I forgot to attach the 4 pin 12V ATX power cable to the motherboard.  I got the 24 pin power connection, but I guess I had seen too many web pages showing the connection of the 24 pin connector and convinced myself that was all that was needed.  The impact? When I turned on the machine, the CPU fan and the case fan would spin, but that was it.  The power LED would not come on, the monitor showed nothing, and I couldn’t turn off the motherboard with the soft switch, but rather had to cut the AC.  I started looking on the web for possible solutions.  I reseated the memory, & CPU, disconnected the HDD and DVD, and checked the power switch connections.  I had all but given up and was ready to contact ASUS for an RMA, when I gave the board one last look over and spotted the 4 pin ‘hole’, then rechecked the ASUS manual and found a very clear statement (as well as a picture): “Do not forget to connect the  4 pin ATX 12V power plug. Otherwise the system will not boot.” Duhuhh.  I’m lucky that I didn’t fry the board with my power cycles.

So, with only a couple of stumbles (er, rather,  “learning opportunities”), I now have a system that will POST.  More importantly, the day after completing the build, my son asked me, “I wonder if my Nintendo DS has the same parts as the computer?”  That alone was worth the time and energy spent. I like seeing the lightbulbs ignite.

Next adventure on the new PC, loading CentOS Linux.