Are Archive hard Drives ok for Readynas?

I don't recommend them as internal drives for the NAS.  A couple users found them acceptable, though many did not.  Seagate does not recommend them for NAS.

I've also seen posts saying the external SMR drives also misbehaved when plugged into a USB port.  If they work for you, be very careful on ejection.  

One option is to connect it to a PC and use it for to back up the NAS over the network.  Last time I checked, Windows drivers handled this drive technology better than linux.

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miogpsrocks wrote:

 

They kind of overlap the magnetic strips like shingles, and have a double wide reader/writer head or something like that. Makes for faster read speeds but slower write speeds. 

 

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The overlap is correct, but the implications are somewhat off.

The overlap allows the drive to hold about 25% more data, which lowers the cost per terabyte.  Read speeds are pretty much the same as PMR drives.

But when you write to track X, the write operation destroys what's on track X+1.  So the writes need to "ripple"

• read track X+1
• write track X
• read track X+2
• rewrite track X+1
• read track X+3
• rewrite track X+2
• ...

The drive is divided into zones (with at least one unused track between the zones).  So the "ripple" continues to the end of the zone.

They are equiped with large caches, and the firmware on the drive orders the write requests to try and minimize the performance impact.  But if you do sustained writes, you will run into a serious performance dropoff.

Another implication is that some commands (spin down for instance) don't take effect for a long time.  The drives will keep running the "ripples" in the background until they are complete.  This can confuse software that expects the commands to take effect when they are issued.