NAS drives. Which kind of hard drives do you actually need...

[sityeuropa]

I have a 2-bay Synology NAS unit and I'm just looking to upgrade my two 2TB drives.

I access my NAS daily. I have it split into two volumes, one for important data and one for movies which wouldn't be the end of the world if it was lost. I use Raid 1 for backup and also have an external drive to backup my important data volume.

I'm looking at the prices of 4TB drives and between the blue and red variants; knowing red to be more suited for a NAS right? Maybe not.

I've had my Western Digital Green 2TB drives for around 5 years and I was checking the Load Cycle Count. The green drives I understand are good for 300,000 cycles. After 5 years I'm only up to 42,000 cycles.

So I don't think I really need a red drive from my usage and will get two 4TB blue drives for around £170. Then after a few years another cheap upgrade when 8TB have come down a bit.

Just giving my experience of how the budget drives have served my uses well and I'm nowhere near the cycle estimates for the drive. A mirror raid and external backup, I think I should be good right?

 

[sityeuropa]

Good points.

My Nas would only be acessed a handful of times a day. So spin down would probably be beneficial from a power point of view.

Do reds spin down.

 

[sityeuropa]

Main issue with Nas vs Non-Nas drives is how they handle errors when used in a RAID configuration. Non-RAID specified Drives will try to re-read e.g. a bad sector hundreds of times without failing the drive (usually causing the array/NAS to become unresponsive until it succeeds, but also potentially causing further damage to the raid array - e.g. by mirroring the bad data). A RAID specified drive will report an error after a short predetermined amount of time, allowing the NAS to make the decision to deal with the problem (e.g. by marking the drive as failed, and removing it from the array).

When using a software raid like Synology, is this a workaround to what you have said?

Desktop/Enterprise Class Drives

Of note, since DSM 2.2Ref: 26, released in September 2009, Synology introduced their own sector recovery subroutine operating in the background, called Dynamic Bad Sector Recovery, to “further enhance the system reliability” with hard drives. This function basically operates in conjunction with DCDs or ECDs, to help maintain availability of a volume when encountering defective sectors on hard drives.