Writethrough SSD cache?

[dsjstc]

Basically I'm looking for a higher-risk, higher-performance version of the Drobo 5N.

It doesn't seem too much to ask for a 2-disk or 4-disk home NAS that gets most of its performance with writethrough caching of HD access through a modestly sized SSD. But I can't find anything in the SOHO space except Drobo's offering.

Am I missing something?

 

[L&LD]

What you are missing is the fact that Drobo is proprietary and in my opinion highly suspect (when data safety and availability is in question).

I don't have a suggestion for you except possibly the QNAP 4/6/870 Pro (just a guess) or those NAS units with the 10G network option.

When Drobo's fail - they fail epically and completely from what I've read.

When you ask for higher risk; the Drobo gives you that in spades.

 

[dsjstc]

QNAP ssd caching

Thanks for the pointer: found this reference listing which QNAP models support ssd caching.
http://www.qnap.com/en/index.php?lang=en&sn=852&c=915&sc=2316&n=20182

It surprises me that the price premium is so high over a basic NAS box to find one with an MSATA port. Feels like artificial product differentiation to me.

 

[L&LD]

Not artificial to the manufacturers. This is how they differentiate between what mere mortals can buy to what big corporations can buy (at $100K a pop entry level 'solutions').

 

[Dennis Wood]

The TS-470 Pro I've been testing does indeed support SSD caching, however this is via an SSD in one of the trays, not msata. In the case of the 4 bay NAS, you would therefore give up one of the trays for SSD caching. My thoughts are that this makes more sense (and I'll test it) with the 8 bay variation.

http://docs.qnap.com/nas/4.0/SMB/en/index.html?ssd_cache.htm

 

[stevech]

Basically I'm looking for a higher-risk, higher-performance version of the Drobo 5N.

It doesn't seem too much to ask for a 2-disk or 4-disk home NAS that gets most of its performance with writethrough caching of HD access through a modestly sized SSD. But I can't find anything in the SOHO space except Drobo's offering.

Am I missing something?

Wouldn't one of the "hybrid disks" (SSD + magnetic) be transparent to the operating system that it is caching?

PS, opinion alert: Drobo-not.

 

[Dennis Wood]

I could find one reference to hybrid drives at least for qnap: http://forum.qnap.com/viewtopic.php?f=182&t=70698

Doesn't seem too positive in terms of performance. I have done performance testing of windows storage spaces with parity, + SSD drive caching, and saw about 150MB/s writes, and 900 MB/s reads with six Hitachi 4TB drives, and 2 x Intel 530 SSD drives set up as journaling/cache drives. That write performance would be fine on Gigabit with a few users, (and no dedicated raid controller!), however Raid 5 writes were more in the 500MB/s using just the six disks and a $170 RocketRaid 2720...no SSD's required.

Given that the storage unit may see 10 workstations saving images simultaneously (each at 50-100MB/s or more), SSD caching, at least with windows storage spaces in a parity arrangement was not so great. I will test it out though on the TS-470 and see what results.