IPhotos eHDD Format Inquiry and Windows Compatibility

To keep this general, here are some things to think about:

DAS: Direct Attached Storage - Thunderbolt, eSata, USB 3.0, FW800, FW400, USB are the rough pecking order. FW400 is better than 100 MB ethernet, and FW800/USB 3.0 are equivalent to Gigabit Ethernet.

NAS: The network matters - latency over WiFi can be a big bottleneck as can the controller chip / lack of cache in less expensive NAS.

Think in terms of the bottlenecks - For streaming a song, AirPlay shows you what to expect - a slight delay, but the system can buffer the music to overcome little lags and delays due to network burps. DAS is much more responsive - especially for little file input/output as opposed to streaming a large file or song.

NAS does offer some nice features like cross platform sharing and with a good network can be shared effortlessly with several clients that don't mind sharing the speed of the device. DAS is designed for one user and optimized for speed - especially for database workloads like iPhoto.

NAS can be harder to back up, where DAS works easier with whatever backup program you use on your mac.

Your iPhoto database will be the last thing you want to move. It has no provision for splitting the large files from the database files and the latency of reading / writing to the NAS might make you feel the program is too slow. Try it out, but don't be surprised if it's the least responsive by it's design.

You want programs that can use local database and thumbnails on the fast SSD and store large original files on NAS or slower storage.

Aperture works amazingly well if you find iPhoto too laggy when stored on the NAS.

I would start with the iTunes media folder - move that to the NAS and see how you like the performance.

Then get a tool like WhatSize or DaisyDisk so you can quickly measure what folders on the SSD are largest as you prune things down.

You might find you don't need all the audio loops from Garage Band or other surprising folders that make a difference in what you want to bring along on the SSD.

Have fun with the tweaking - you'll learn how things work. Also, it won't be long until ThunderBolt storage is more available - your NAS might even have a DAS connection for when you really need some speed to access / move files to the NAS.

Don't forget to back up your NAS. CrashPlan might be a great thing to try for that.

Taking aside the part that says which OS a particular filesystem is associated with, the main point is the word "journaled".

I include the following Wikipedia quote as there is no point re-inventing the wheel:

A journaling file system is a file system that keeps track of the changes that will be made in a journal (usually a circular log in a dedicated area of the file system) before committing them to the main file system. In the event of a system crash or power failure, such file systems are quicker to bring back online and less likely to become corrupted.

Taking that to one logical end, an external drive is by definition more likely to be removed from the system than an internal drive. It's not possible to remove your laptop drive and keep the OS running, but perfectly possible with something USB or Firewire attached for example. As such you run a greater risk of changes that need to be written to the drive failing to complete should you remove the drive too quickly, or without following the correct eject procedures.

Particularly if you use any form of caching, the data may be waiting to be written to the disk at the point of removal, thus losing your data.

A journaled filesystem helps to prevent too much damage in these scenarios by keeping a log of all changes it needs to apply, and noting when they are successfully completed. In this way it can examine the log on a restart and work out of there are outstanding changes that were never completed. This is far faster than simply running a chkdsk or similar command to check the entire filesystem for problems which you would need to perform on a FAT32 file system.

In addition to the protective side of things discussed above, is the fact that a HFS filesystem has all the Mac OS X hooks built in for automated indexing, backup, version control and so on that would not be possible on a FAT32 enabled filesystem.