My server has always used an old WD Raptor 150GB as the cache drive. I recently added a Crucial 240GB SSD as an unassigned device and added some Windows VMs to it which (currently) aren't taking up much space. 

 

I'm wondering: 

1) Should I keep the Raptor as the Cache drive or make the SSD the cache & VM drive? I suppose that *may* cause VM performance to suffer a bit. 

2) Maybe the Raptor should stay the Cache drive but perhaps I should move the docker image, appdata and downloads folder over to the SSD as it has more room to spare. 

 

I'm Finally in the process of setting up dockers other than Plex and am wondering where to put downloads. I've seen people put them on a user share, which protects them but means at least another disk needs to be spinning. In terms of power consumption, that's another point for putting it on the SSD. Should the SSD fail before a download gets moved, I can probably re-download whatever is lost. 

 

What would you do with those drives at your disposal?

Use the Raptor for downloads, cache and 'static' stuff like the isos share.  Keep appdata and VMs on the SSD.  Lots of writes during downloads can wear a SSD really quite quickly, especially newer TLC drives.  Old MLC and SLC drives are fine and have plenty of endurance. 

 

For example, I wiped 10% life off a 750 Evo in less than a month when using it for downloads in my server.  Cheap TLC drive, total junk.

 

Now I use a pair of cheap drives in a cache pool, and not really fussed if they die.  If I had a pair of 2.5" 7200rpm drives, I'd probably have used those instead, but I had the SSDs spare.

Edited April 4, 20179 yr by HellDiverUK

Thanks for the reply HellDiver, makes sense. So pretty much the way I have it except move the appdata to the SSD.

 

Is that a stright-up move and remap/configure dockers or is there something else I should be considering.

 

Also, for downloads on the cache drive, is using the dot prefix for the directory still the best way to ensure it doesn't get moved off the drive? Otherwise unraid seems to automatically create a share for it on the array.  

 

 

On ‎4‎/‎4‎/‎2017 at 10:24 AM, HellDiverUK said:

Use the Raptor for downloads, cache and 'static' stuff like the isos share.  Keep appdata and VMs on the SSD.  Lots of writes during downloads can wear a SSD really quite quickly, especially newer TLC drives.  Old MLC and SLC drives are fine and have plenty of endurance. 

 

That hasn't been a thing since 2014. Consumer level SSDs can now sustain PETABYTES of data written before dieing. Being concerned with write-levels on SSDs are a thing of the past.

 

Hitting the 1 PETABYTE range in 2014: http://techreport.com/review/26523/the-ssd-endurance-experiment-casualties-on-the-way-to-a-petabyte

Eventual death at 2 PETABYTES: http://techreport.com/review/27909/the-ssd-endurance-experiment-theyre-all-dead

 

With 2014 level TLC technology, the drive sustained 900TB writes before dieing.

After receiving a black mark on its permanent record, the 840 Series sailed smoothly up to 800TB. But it suffered another spate of uncorrectable errors on the way to 900TB, and it

died without warning before reaching a petabyte.

 

24 minutes ago, BRiT said:

 

That hasn't been a thing since 2014. Consumer level SSDs can now sustain PETABYTES of data written before dieing. Being concerned with write-levels on SSDs are a thing of the past.

 

 

 

Disagree.  I burnt through 10% life on a Samsung 750 Evo in less than a month doing a heap of downloads from newsgroups.  On a 20Mb line.  That's a TLC drive.

 

That Techreport test wasn't using the current generation of economy TLC drives, either.  On the most part budget drives in 2017 are junk compared to the likes of Samsung 840 Evo or SanDisk UltraII.

 

I stick to MLC drives now, on the most part.  TLC are fine for everyday PC use that is mostly reads, but they suck for server use with lots of writes.

 

The drive in my server is an older Crucial M500 MLC drive. Stuck it in as I expected it would fare better, but still think it's prudent to keep the thrashing to the Raptor for as long as it'll hack it.