Is my PS3's HDD dying?

[Ex-Cyber]

I bought Vanquish the other day, and I've experienced some occasional unexpectedly long load times (or hangs, perhaps) on a black screen, with no indication that it's loading. The game would always eventually keep going, but in some places it would pause on the black screen for almost a minute. I haven't seen anyone else mention this problem, and I believe it's bad enough that people would be out there demanding a fix it if it were a game bug.

My first thought was that the Vanquish disc might be defective, but then I exited the game and the XMB was stalling as well. Controls were unresponsive a couple times, and it spent a long time trying to load the "Game" menu. The system wouldn't even shut down normally; it sat there blinking the LEDs at me for a while before it finally turned off. Upon rebooting it ran a bit more normally, and I watched a couple minutes of a Blu-ray movie to make sure the BD drive hadn't catastrophically failed.

My PS3 is a CECHA01 with the original HDD, which means that it's fairly old, and combined with the fact that I've seen similar behavior patterns on PCs with dying HDDs (OS or app hangs because the HDD stalls when accessing damaged areas), I think that implicates the HDD. However, I'm not experienced enough with PS3 diagnosis or repair to know what else might be causing it. So, can anyone confirm/deny that this behavior pattern suggests a dying HDD, or suggest something else that's likely to cause it? I'm not running CFW or doing anything else strange that I can think of; it's an original BD-ROM running on OFW 3.41, and I've never installed homebrew packages on this console.

Also, can anyone confirm that it's safe to run SeaTools non-destructive diagnostics on a PS3 drive?

edit: tried to back up the drive, and the PS3 ended up on a black screen; not sure when in the process it happened, but it wasn't right away. Went into "safe mode" and used the "Restore File System" option, which was way too fast to have done any real media test, but I haven't been able to reproduce any problems since then (though I haven't been trying for very long). I also went ahead and ran SeaTools for DOS v2.22 "short" and "long" tests on the drive, and both passed, so I guess this may have just been filesystem corruption of some sort. Going to try another backup and then maybe format the drive and restore if problems pop up again.