FireWire and a union file system (aufs)
News, Technical ·Friday September 10, 2010 @ 19:01 EDT (link)
My first ever exposure to IEEE1394b (what Apple calls FireWire 800), which I opted for rather than (continuing with) USB due to the ability to chain devices rather than needing more and more sockets. My Syba PCIe card and Lacie d2 Quadra 2Tb external HD arrived Tuesday, and I finally got around to setting it up—fairly simple really, put in the card, connect the drive and format it ext3 (which holds its own quite well speed-wise against JFS, XFS, and Reiser, is better supported and more actively developed, and I know it well enough to fix a botched disk with a hex editor).
I also took the opportunity to upgrade the kernel (2.6.35) on the server and media machines, and did a little research and installed aufs (another union file system) (as it happened, the original unionfs failed to install). A union file system allows two physical drives to overlap in one directory—so movies stored on the new drive can appear in the same path as the old—without all the irreversible inconvenience of something like LVM. I did manage to get aufs to refuse to unmount once, though, with no files apparently in use, and forcing the module to remove lead to an understandable kernel BUG and instability until I restarted. But it's been well-behaved since, even shared over NFS.
