Posts Tagged ‘Cache’

Synology NAS and SSD Cache Part III – Is cache better for VMware vSphere (ESXi)? Confusing results!

Monday, April 11th, 2016

So in today’s, crude and experimental research I thought I would connect all our VMware vSphere Hypervisors (ESXi 5.5 build 1892794) to a NFS datastore presented to the ESXi Hosts from a Synology NAS, and we’ll try the following tests

I deployed a small Windows 7 template, onto the NFS datastore as follows

  • No Cache Enabled – 3 minutes 27 seconds to deploy
  • Read and Write Cache Enabled – 2 minutes and 40 seconds to deploy.

Time for some more testing – The template deployed to the datastore was converted to a virtual machine, and the following tests were performed using CrystalDiskMark 5.1.2 in the virtual machine.

NFS Exported volume No SSD Cache on the Synology NAS.

NFS Exported volume Read and Write SSD Cache on the Synology NAS.

NFS Exported volume Read only SSD Cache on the Synology NAS.

Some a bunch of very confusing results! And every time I test the results are similar.

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Synology NAS and SSD Cache Part II – Is cache better for Plex Media Server ?

Sunday, April 10th, 2016

In my recent article comparing the performance of the addition of a Read and Write SSD Cache to a volume on a Synology NAS, I started to look in detail at whether this cache benefits any other services on a Synology NAS running DSM 5.2.

In this experiment I’m looking at the Plex Media Server, and I’ve setup two identical Synology NAS, running DSM 5.2 Build 5644 Update 5, both with Plex Media Server 0.9.15.2.1663, both are streaming the same 1080P Blue Ray movie to the same Plex client via WiFi, at the same time. The first NAS has no cache, the second NAS has 120GB of read and write cache, and these are the results.

The second NAS with the read and write cache enabled shows, lower Disk Utilization 1% compared to 5%.

Again you can see here, 6% (no cache), 1% (cache)

The same stats from both NAS, No cache and cache enabled, what is interesting is the CPU load results are lower on the cache enabled version!

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Synology NAS and SSD Cache

Saturday, April 9th, 2016

I’ve been recently experimenting with SSDs (solid state disks), to accelerate my spinning rust in my Synology NAS.

Recently in DSM, a new SSD cache option is available, which allows you to create a read or write cache with 1 or 2 SSD devices respectively.

Here are some results, which I’ve graphed

2016-04-09-21_26_42-microsoft-excel-book5

In my very quick and crude tests, I could see an improvement in Writing to the NAS, which doubles in performance. Read speed is very similar, and the cache was “warmed-up” before testing.

And here’s a video of the new Synology SSD Cache Read Hit Rate graphic, which looks a little graphic equalizer, from the 70-80s, so I’ve dropped a music track in the background! I thought it only right to over-flange (distort!) the track, so you may want to turn down your volume!

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