Should I change my disks from "always on"

[jordanthompson]

My TrueNAS instance only supports my wife and me (mostly just me.) We use the primary pool for storing old pictures, periodic laptop backups, git databases, etc. It consists of 8 x 2tb drives so that I can lose two drives and maintain data integrity. We don't really hit it very much. There is a Plex pool of four SSDs (we don't hit it very much and they are more efficient and run cooler). The OS is on another pool of two SSDs.
Also, the machine has 64gb of RAM.

At some point I plan to have a web-based (with only a handful of users) database in its own jail or VM (if I go to the Linux version of TrueNAS). At that point I will probably add a dedicated pool for it and back it up periodically to the main pool (again, not much traffic on the main pool.)

The drives are set at "always on". I have read it's not a good idea to have them spin down only to spin back up, but I feel like my case is different... Should I change this for my main pool? If so, what value do you recommend?
Is there any way to see how often they cycle once I change the setting?

 

[winnielinnie]

"Always On" is better for the life of the drives. I would leave it as is.

 

[jordanthompson]

FWIW, I have another (old) NAS that powers up once a week and stays up for around 24 hours. My TrueNAS rsync's with it during this time. This other NAS gives me no issues at all with its four drives and (IMHO) its because the duty cylcle is less than 15%. The TrueNAS on the other hand has had a spate of HDD failures that I originally thought may have been due to heat, but on "researching" the temps see they are well within tolerance (30-33 °C - the drives are rated to 65°C). Luckily they were within warranty so I was able to RMA them as they were all bought at around the same time.

 

[joeschmuck]

My personal belief (personal is the key word here) is that if your drive does not spin up more than 3 times a day then you should be good. You get into a real problem when the drive spins down and then spins back up every 5 to 10 minutes. Will that void the warranty? Not on most current drives but we are really not talking about the warranty here, it's the fact of having a problem with the drive in the first place. Most WD Red drives will last almost double the warranty period running continuously.

My "personal" advice, given your specific use case, sleep the drives and monitor the spin-up count, make sure it is doing what you expect it to do. If you think it should be sleeping for more than a 24 hour period and it spins up, you should figure out what is causing it, and it could be many things. Also try to track how long the drive remains active.

If the drives are spinning up many times a day, that is when I'd recommend leaving them spinning.

Hopefully this makes some sense to you, I suspect it will.