Is disk part of parity calculation

[Thomas_K]

After the upgrade to Unraid 6.2 it's not possible to use an "Unassigned Device" as dockerstorage. Due to that i've installed my SSD into the array,

 

and then removed the drive from the "Global share settings"

 

but now i'm wondering wether the disk(disk22) is part of the parity calculation or not.

 

I was looking at installing my SSD as a Cache device, but it's i don't think it's possible to force my docker to use only the SSD. Further I haven't found it possible to only use my normal cache drive for my array

 

Is disk 22 a part of the parity calculation. If so, please advise how to solve this issue

 

br,

Thomas

[garycase]

Yes, if it's part of the array, it's included in the parity calculations -- so writes to the SSD will be MUCH slower than if it was an unassigned or cache device.

 

[Thomas_K]

Yes, if it's part of the array, it's included in the parity calculations -- so writes to the SSD will be MUCH slower than if it was an unassigned or cache device.

 

That was what i was afraid of. As "Unassigned Devices" can't be used anymore, and as it's not possible to assign my SSD as cache an only use it for my Dockerapps. I wonder why Lime Tech removed the posibility to use "Unassigned Devices"

 

Thomas

[itimpi]

Yes, if it's part of the array, it's included in the parity calculations -- so writes to the SSD will be MUCH slower than if it was an unassigned or cache device.

 

That was what i was afraid of. As "Unassigned Devices" can't be used anymore, and as it's not possible to assign my SSD as cache an only use it for my Dockerapps. I wonder why Lime Tech removed the posibility to use "Unassigned Devices"

i believe is due to the fact that on many systems the unassigned Devices plugin does not always mount its drives before docker is started, so on such systems docker will fail to start. 

[Thomas_K]

Yes, if it's part of the array, it's included in the parity calculations -- so writes to the SSD will be MUCH slower than if it was an unassigned or cache device.

 

That was what i was afraid of. As "Unassigned Devices" can't be used anymore, and as it's not possible to assign my SSD as cache an only use it for my Dockerapps. I wonder why Lime Tech removed the posibility to use "Unassigned Devices"

i believe is due to the fact that on many systems the unassigned Devices plugin does not always mount its drives before docker is started, so on such systems docker will fail to start.

 

Ok, but it worked flawlesly on 6.1

 

I've never had any problems until now

[tdallen]

Why can't you setup the SSD as your cache drive?

[Thomas_K]

Because the one i have is to small.

 

[garycase]

Because the one i have is to small.

 

Easy to fix that problem 

https://www.amazon.com/Crucial-MX300-525GB-Internal-Solid/dp/B01IAGSD68/ref=sr_1_1?s=pc&ie=UTF8&qid=1474986595&sr=1-1&keywords=Crucial+MX300

 

[tdallen]

I agree, that's a pretty easy problem to fix.  Even if money is an issue 180GB is a decent size SSD for a cache drive if you are only going to use it for Dockers.  I don't use my cache drive for write caching to the array, I find that writes directly to the array are fast enough for my purposes with the bonus that my data is always protected by parity.  That leaves my entire cache drive available for the docker image and appdata.