TS-XEL only 3 green drive lights 4th is out, no errors on display?

[AnySupport]

I'm certainly not running out of space. And I'm not really trying to do anything overly demanding on it. (No gaming, music streaming (although it does have my music library on there.) )

Is this one of those "when it's not broke, don't fix it" situations? Where you just ride it into the ground? 
I tend to not do that with computers, but I work remotely so having crippled PCs would be a far riskier situation, than if it were just a casual browsing and low-level gaming device.


Also, is it safe to run backup jobs from the degraded device to another connected NAS? Or could that cause corruption and should just be avoided until the drive swap and RAID rebuild actually completes. (always seems to be a couple days. No progress indicator anywhere has been one of the few pet peeves of this system.)

Thank you very much!

[Texturtle]

I would highly recommend running a backup regardless, and once you get the drive replaced and the array rebuilt I'd advise updating the firmware on the NAS.