Question NAS and HDD (rpm vs cache)

[modeonoff]

Hi, I have not bought a HDD for many years. Never bought a NAS HDD before. For NAS HDD, what cache size is recommended? If a NAS drive has 256MB cache, will adding SSD cache or RAM help in improving performance? If I add SSD as cache, is it better to get a slower spinning 5400rpm drive with smaller cache than a 7200rpm one with 256MB cache? Between SSD and RAM, which is more important for better performance?

 

[USAFRet]

Hi, I have not bought a HDD for many years. Never bought a NAS HDD before. What cache size is recommended? If a NAS drive has 256MB cache, will adding SSD cache or RAM help in improving performance? Between SSD and RAM, which is more important for better performance?

"What cache size is recommended?"
It truly does not matter.

"If a NAS drive has 256MB cache, will adding SSD cache or RAM help in improving performance?"
Unless you are doing REALLY intensive I/O operations, no.

Intensive, like hosting a big database server, or having a hundred or so simultaneous users.

"Between SSD and RAM, which is more important for better performance"
RAM.
I have a 480GB SATA III SSD as the system drive in my QNAP.
Accessing the NAS from my PC, can't tell the difference vs any of the HDDs.
Why? The gigabit LAN is the slow actor.

 

[fzabkar]

Just be careful. WD has been caught stuffing SMR drives into their Red NAS line-up.

 

[modeonoff]

"What cache size is recommended?"
It truly does not matter.

"If a NAS drive has 256MB cache, will adding SSD cache or RAM help in improving performance?"
Unless you are doing REALLY intensive I/O operations, no.

Intensive, like hosting a big database server, or having a hundred or so simultaneous users.

"Between SSD and RAM, which is more important for better performance"
RAM.
I have a 480GB SATA III SSD as the system drive in my QNAP.
Accessing the NAS from my PC, can't tell the difference vs any of the HDDs.
Why? The gigabit LAN is the slow actor.

For a 1-person case, how much RAM is sufficient?

I think you have a 4x4TB system. 1-3TB NAS HD are difficult to find. Looks like these days, 4TB/bay is the minimal. If buying now, how many TB/bay is recommended? Initially, I probably just buy 1-2 HDD for testing and mirroring. Is 4-bay sufficient? I want mirroring backup and capacity to add more HDD , perhaps the same or larger size later without throwing out lower capacity ones.

 

[USAFRet]

I think you have a 4x4TB system

Currently, in or attached to my QNAP.

QNAP TS-453A:
480GB SATA III SSD (system drive)
8TB HDD
14TB HDD
18TB HDD

QNAP TR-004:
4x 4TB

4 bay MediaSonic:
16TB HDD
8TB HDD
3TB HDD
3TB HDD (to be replaced by an 8TB)

If buying now, how many TB/bay is recommended?

That all depends on YOUR needs.
If a 2 bay meets your needs and budget, than that.
Otherwise, a 4 bay.

Drive size is totally on your space needs and budget.

 

[modeonoff]

So if I get a 4-bay NAS, than I can mix and match drives of different sizes and do mirroring? I think in the past, somebody recommended 4 or 6 rather than 2-bay NAS.

 

[USAFRet]

So if I get a 4-bay NAS, than I can mix and match drives of different sizes and do mirroring?

Well yes and no.

Each drive would be its own Volume.
You could do a Sync between 2 volumes, and even only specified folders.

For instance, the 18TB in the TS-453a is the main data repository.
It does a one way sync once a week to the 4x4TB JBOD volume in the TR-004.

But you can't do a RAID 1 mirror with drives of different capacities.

 

[MrN1ce9uy]

I would s

So if I get a 4-bay NAS, than I can mix and match drives of different sizes and do mirroring? I think in the past, somebody recommended 4 or 6 rather than 2-bay NAS.

While you can mix and match drives, you would have to match the drive sizes for mirroring. I built a file server using Windows and RAID 10 with 4x drives. I would only mix and match if you already have drives laying around. If you are building/buying new drives, get all the same.

 

[modeonoff]

Somewhere I read that NAS/NAS HDD usually last for about 5 years. Is that really true? At least for the time being 6TB is the best for my need but 4TB drives are better deal.

 

[DSzymborski]

But you can't do a RAID 1 mirror with drives of different capacities.

I'd totally consider that a feature more than a bug! lol

 

[USAFRet]

Somewhere I read that NAS/NAS HDD usually last for about 5 years. Is that really true? At least for the time being 6TB is the best for my need but 4TB drives are better deal.

Read where?

Drive lifespan can only be read on a fleetwide basis.
An "average" means little to your drives.

The drives in your system might last a month or a decade.

 

[fzabkar]

But you can't do a RAID 1 mirror with drives of different capacities.

Is that really the case? Why wouldn't the RAID controller simply ignore the extra capacity on the larger drive?

 

[USAFRet]

Is that really the case? Why wouldn't the RAID controller simply ignore the extra capacity on the larger drive?

Well yes, you can.
But throwing away drive space you paid for.

4TB + 8TB + RAID 1 = 4TB RAID array
4TB + 8TB + RAID 0 = 8TB RAID array

 

[modeonoff]

I am still trying to decide whether to get a NAS or not. One annoying thing I have is that with different computers and OSs used over the years, I cannot access all the files I want whenever I want without some sort of compatibility problem. For example, I used to use a MacBook Pro with Bootcamp and Linux as my main work computer. Now I use a desktop PC as my main work computer. When I connected some external drives to it, some drives were not recognizable. Sometimes Windows just requested that I format the drives (some of them I have no idea what contents are stored) to use it. I read that NAS can store files from different OS. Will getting a NAS solve this problem?

 

[USAFRet]

I am still trying to decide whether to get a NAS or not. One annoying thing I have is that with different computers and OSs used over the years, I cannot access all the files I want whenever I want without some sort of compatibility problem. For example, I used to use a MacBook Pro with Bootcamp and Linux as my main work computer. Now I use a desktop PC as my main work computer. When I connected some external drives to it, some drives were not recognizable. Sometimes Windows just requested that I format the drives (some of them I have no idea what contents are stored) to use it. I read that NAS can store files from different OS. Will getting a NAS solve this problem?

In my QNAP, I can access the files from any system in the house.
Windows, Linux, Android. I have no apple devices.