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The N40L NAS with the Icy Dock DuoSwap

A recent tech buy was an HP ProLiant N40L MicroServer, which serves as a NAS, a Sick Beard/SABnzbd+/Deluge server, and as a backup server.

I’ve added an IcyDock Duo Swap to the 5.25″ bay. I use its 3.5″ bay for rotating HDD backups, and its 2.5″ bay for the system SSD. Having the OS drive in a hotswap bay is pointless, but it kept the case neat.

There is a fifth SATA port on the motherboard, but to use a sixth drive I was required to use a SATA to eSATA cable and poke it out to the eSATA port at the back of the case. I also found the case fan a bit noisier than I liked, so I replaced it. Concerned by the possibility of buying an incompatible PWM model as warned by this article, I used a non-PWM fan and set the RPM manually.

In order to make the drives hot-swappable I was required to install a modified bios and alter some advanced configuration settings.

Ubuntu-server 12.10 is installed, along with Sick Beard, SABnzbd+, and Deluge. At some point it may also host an XBMC database, so to handle these services better I’ve upgraded the box to 8GB RAM.

Both AFP and CIFS are used to allow my MacBook and HTPC to connect to it with ease. I briefly played with NFS but couldn’t get the bindings and permissions to work correctly. I like that the client machines use their own native mechanisms, anyway.

I’ve also made it a printer server by installing CUPS, and I made it work for iPads by installing Avahi, roughly following this method.

I played around a bit with software RAID via mdadm (the advertised integrated RAID is only FakeRAID), and it works well, but ended up just going straight with the various HDDs I had sitting around. I don’t need redundancy, I just wanted backups of my documents and photos.

Local backups are made using rsync and rotating external HDDs in the DuoSwap. Automated external backups are performed using the excellent little tool encrb to upload encrypted data to a private server.

That’s about it.

Force RGB mode in Mac OS X to fix the picture quality of an external monitor

Update: I have heard that 10.8.3 has solved this problem for some people, so I rolled back my changes and installed the update. No change on my monitor. Nevertheless, it’d be a good idea to update OS X before trying this, since it may fix the issues with your particular hardware.

I recently bought a MacBook Pro (with ‘Retina’ screen), but when I hooked it up to my Dell U2410 monitor via HDMI cable I was shocked by the poor picture quality. The contrast was all wrong and text was misshapen. No amount of calibration in the monitor or software would fix it.

Short answer: OS X thinks my monitor is a TV, and is using the YCbCr colour space rather than RGB. I had to override an EDID setting to force the RGB colour space, and it is now working correctly.

Long answer: I haven’t owned a Mac for a while and had forgotten how useless most of the “Apple community” is when it comes to anything that can’t be adjusted in System Preferences. Googling for problems with external monitors on MacBooks found dozens of threads on official and unofficial Apple forums, all full of people with the same problem. The most common responses from the Apple geniuses was to blame the monitor, despite assurances from the stricken users that the monitor worked beautifully in Linux and Windows, even on the same machine under Boot Camp.

“You just haven’t calibrated it!”, “You are just too used to Retina now!”, “You just need to buy a Thunderbolt display!” Apple people also like to solve problems by throwing more money at it. (I realise that owning a Mac makes me an Apple person, too. Hypocritical self-loather?)

My lucky break was reading that the current colour space was “YCbCr” when I was browsing the monitor’s settings menu. I was sure that it was using RGB when hooked up to my PC, so I started searching instead for forcing RGB mode in OS X. It didn’t appear to be available out-of-the-box, but I have had some experience in overriding EDID settings for similar purposes so I searched instead for that.

I found this thread on the EmbDev.net forums. Mr Schwarz, thanks very much. Your thread and script was incredibly helpful and informative. It was written to fix problems connecting an external monitor via DisplayPort, but it fixed my HDMI issue just the same. I’ve summarised the required steps below.

My last word is to wonder what Apple is playing at. It seems that this problem has been reported by a lot of people for a long time, and I expect it would require a fairly simple software update. Do they just not care about those using third-party components, or are they actively attempting to force people on to Thunderbolt displays?

How to force RGB in Mac OS X

  1. Download the patch-edid.rb script from the forums thread above and put it in your home directory.
  2. Connect only the external monitor(s) in question (I closed my MacBook lid, for example). The script will make override files for any connected monitor.
  3. Type “ruby patch-edid.rb” in Terminal.
  4. A new folder will be created in your home directory. Move it into the “/System/Library/Displays/Overrides” folder. If Finder tells you that you are overwriting an existing folder, consider backing it up first.
  5. Restart your computer, enjoy your monitor.

To undo the changes, either delete the folder you had copied to the Overrides folder (if it didn’t already exist) or replace it with the folder you had backed up.