ReadyNAS Pro Business: Fan spinning often?

Blues wrote:
In general, the machine is quieter with the fan speed usually in the 900-1100 range, but it still has some periods (10-15 minutes) where the fans will get up over 2000 RPM.

If the high-speed periods correlate with known periods of high load on the NAS, that's nothing to worry about; the fans are just doing their job. On my Pro 6, for example, the fans spin up for a few minutes every four hours when a complete rsnapshot backup is run, and every night when the updatedb command runs, etc.

Blues wrote:
My concern is that I may have injured one or more of the fans when previously doing this process (and not holding the fans).

Fan bearings will usually start to make more noise when they're damaged, and the noise often gets progressively worse with time. If your fans aren't noticeably louder now than they were before, and if you don't see any other symptoms of a damaged fan (fan unable to run at low speed without stopping, or refusing to spin at all, or running constantly at a much slower speed than normal -- or an "Out of Spec" warning on the Frontview "Health" page) I wouldn't be concerned.

Blues wrote:
If I did damage the fans, can I replace them myself? If so, where would I order replacements?

It's easy to replace the case fan at the upper rear of the NAS. It's slightly harder to replace the CPU fan on the side. Replacing the fan in the power supply (at the lower rear of the case) is a time-consuming, awkward, potentially dangerous process that's probably more trouble than it's worth; if that fan goes out, I'd recommend replacing the whole power supply.

I replaced all the perfectly-good fans in my Pro 6 with fancy Noctua fans, but that was mostly because I was bored and didn't have anything else to spend time or money on that week. The fans that come with the NAS have been carefully chosen for it; they're excellent performers with really good airflow specs, and they don't cost a lot of money or draw a lot of current -- their only shortcoming is that they're a little loud -- so if one of your fans needs to be replaced, it would make sense to replace it with exactly the same model.

These are the fans that came with my Pro 6:

Case: Crown Electronics AGE12025B12M(-067)
CPU: Crown Electronics AGE08015B12V
Power Supply: ADDA Corp AD0812HB-A70GL

You can probably find replacements by searching the web for those part numbers.