All my disks are 4 TB 5400 RPM NAS, but looking to upgrade parity to 8 TB - any benefit to 7200 RPM?

[jademonkee]

As you can see from my sig, I currently have 4x 4 TB 5400 RPM Seagate NAS drives in my array, as well as some 5400 RPM 2.5" drives.

A couple months ago I had a disk fail and replaced it with another 4TB 5400 RPM Seagate NAS drive. I realise now, as a couple disks approach 90% full (and one has now surpassed it), that I probably should have bought a bigger disk instead.

So I'm thinking of wiping and selling the new(ish) disk, and replacing it with an 8TB NAS model so that I can have an upgrade path in the near future (I have no more room in my microserver for any more disks, and don't want to have to sell and upgrade the bulk of my hardware).

 

Anyway, my question is this: 

I can only find 8 TB NAS drives at 7200 RPM rather than 5400 RPM. I'd previously been lead to believe that 7200 RPM is overkill for light usage network storage, so I've preferred the heat, noise, and power savings that the slower drives have brought me.

But now that I can only find 7200 RPM NAS drives I'm wondering if those assumptions I've had are correct. 

Is there a benefit to having a 7200 RPM parity drive in an array of otherwise 5400 RPM drives?

There's only one other user in the house, and the heaviest usage the server sees is streaming to Plex while listening to music elsewhere in the house. 

I am totally happy with the current performance in my array.

Is there any benefit to adding a 7200 RPM drive (as parity) to my array, or will it just increase heat, noise, and energy consumption?

I'm more interested in maintaining low noise levels than I am improving performance (the server lives in the spare bedroom).

 

Bonus question: I've previously stuck to NAS drives because of their warranty, 24/7 usage rating, and vibration tolerance, but are they overkill for my server? Should I just save myself the £50-£80 extra for a NAS 8 TB and just shuck an external (again this is for my parity drive).

 

Many thanks for your insight.

[Hoopster]

6 minutes ago, jademonkee said:

I'd previously been lead to believe that 7200 RPM is overkill for light usage network storage

I have an array of 8TB 5400rpm data drives with an 8TB 7200rpm HGST Parity drive.  Parity checks take about 16.5 hours.

 

My backup server has an 8TB 5400RPM Western Digital parity drive.  Parity checks take approximately 2 hrs longer, but, this is largely due to smaller capacity disks which are slower in reading the data as it takes more platter revolutions to read in X amount of data vs. the denser 8TB drives.  If all data drives were 8TB as well, I think the parity check times would be much closer although the 7200rpm would likely have a slight advantage.

 

In normal parity write operations, I doubt you would see a lot of difference unless you commonly write large amounts of data at the same time.  If this is a concern, it could be mitigated by using reconstruct write mode or caching/mover so you would not notice it anyway.

 

I have seen no difference in noise levels.  The 7200rpm drive does run 2-3C hotter during a parity check, but, that is the only difference I have seen.

 

To answer your question directly, a 7200rpm parity drive will not provide a huge speed burst over 5400rpm when your data drives are 5400rpm.  Parity checks involve reading all data drives so you will be somewhat constrained by the slowest drive regardless of parity drive rpm speed.  With everyday parity operations, any potential speed difference is not likely to be noticed unless writing a lot of data.

 

All of my 8TB drives (except the 8TB 7200rpm HGST parity drive) are shucked.  They are a mix of WD Red (NAS) and White label drives.  In your case, the price differential between NAS and non-NAS drives is likely not worth it.