QNAP TS-932PX-4G NAS OOBE — NAS3 configuration

Now that I have both TS-932PX-4G’s operating, and the defective one sent back to Amazon, it’s time to optimize the configurations for my use.

Here are my objectives.

1. Flat address space of at least 32 TB.
2. Wire speed reads and writes over 10 GbE connections.
3. Tolerant of at least one drive failure, and preferably two.

Spoiler: I can satisfy the first and third objectives, but not simultaneously with the second.

The first thing to go is make sure one side of the transfer is fast enough. I copied a directory of large files from my PCIe 32 TB striped array to itself.

This is slower than it would be if I had two PCIe arrays, but indicates that the one I have should come close to wire speed over a 10 GbE connection if the other end is fast enough.

The next test is from the PCIe array to a TS-932PX-4G four-disk RAID 10 made up of 20 TB Toshiba spinning rust drives.

I had hoped for about double this speed.

As expected, given the RAID 5 and 6 write speed limitations, it’s even slower writing to a RAID 6 four-disk RAID 10 made up of 20 TB Toshiba spinning rust drives.

Configuring a 1 TB Sandisk SSD as a cache doesn’t help much.

But a 4 disk striped and mirrored array of 4 TB Sandisk SSDs gives a welcome write speed improvement.

 

A four way striped array of SSDs is no faster:

 

QNAP offers a capability for disk tiering that they call Qtier. It’s not a cache. The capacity of both fast disks and slow disks are added to get the total array storage capacity. Whether data is stored on the fast disks or the slow ones is determined by how recently the data was written or read, as with a cache, but moving data between the fast and slow tiers is best done when the array is not being used for reading and writing data. Qtier lets you schedule the time for the tiering, or, if there is no a priori good time known, it will do its best to automate the scheduling.  I chose to have the tiering done at night:

I set up the slow array as a 4 disk RAID 6  array of Toshiba spinners, and the fast array as a 4 disk RAID 10 array of Sandisk 4 TB SSDs.

That gave me what I am coming to accept as reasonable performance.

 

Here’s what you get with GoodSync:

 

I transferred about 17 TB of data with no errors. Looks like the Sandisk SSDs are compatible with this NAS.

Here’s the limiting factor in the data transfer rate:

The next morning, the tiering software had freed up a quarter of the space on the fast array by transferring about 2 TB of data to the slower array:

I think this is about as good as I’m going to be able to get with this hardware.