Readynas 628X - What is the fastest possible write speed???

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Flix35 wrote:

The drives claim to have up to 260MB/s speed, but I am getting about 850MB/s speed for writing.  

Well, "up to" is a key word.  

• When you say you are "connected at 10G from the source" do you mean that there are no intervening switches (the NAS is directly connected to the source)?
• What protocol are you using to transfer the data?
• Is the source sending a single stream of data, or are there multiple transfers in parallel?
• Can you tell us the speed your application actually needs (instead of "as fast as possible)?

If you have snapshots enabled, turn them off.  Similarly, turn off volume quota, volume checksums, bit-rot protection, and auto-defrag.

Note you can test the raw filesystem speed with SSH (eliminating the network and file transfer protocol).

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Flix35 wrote:

could it write faster if I linked the two 10G ports together? 

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850MB/s translates to 6.8 gpb/s, so you don't seem to be limited by the link speed with your current configuration. If you meant 850 MiB/s, then you'd be running about 7.2 gpb/s.  You won't get more than about 1.2 GB/s performance over a single 10G port (10000 gbit/s is 1250MB/s or 1192 MiB/s).  So if you need more speed than that you'll need some form of bonding.  Whether that can work for you will depend on the source (particularly since you are concerned about write speed).   What OS is the source platform running? Linux?

When StorageReview tested the RN628x they found 1.3 GB/s write performance with SSDs in RAID-10, and 2.3 GB/sec read performance for CIFS.  This was using a large block sequential write test (128k).  They saw faster write speeds with iSCSI (1.8 GB/s).  Mechanical hard disks measured about 10% slower in this test - but it is specifically designed to minimize any disk seeks.  Generally speaking, SSDs will deliver consistent sustained performance for writes, while mechanical drives won't.

If you aren't running iSCSI, then I suggest trying that next (assuming the source supports it).  If there is no speed increase, then consider the possibility that you are limited by the source and not the ReadyNAS.  

If that doesn't help enough, then I'd try a test with a RAID-0 array of SSDs next. Perhaps Samsung 860 EVOs.  The disk write performance measures ~470 MB/sec for sustained writes, so I'd suggest a test with 3 SSDs.  Theoretical speed would then be slightly higher than a single 10 gb link speed.  RAID-0 with 8 SSDs should be significantly faster than a bonded 10 gb/s connection (though it might not have the capacity you need).