Use Cache for myapps or no

[VladoB]

Dear team,

 

what is logic behind, should I use cache drive for myapps or no?

 

I mean, I changed my cache drive and lost all my krusader and plex etc.

 

many thanks for your advice

 

Vladimir

[trurl]

CA Backup plugin will let you backup your appdata. That is all you need to recreate your dockers from Community Applications - Previous Apps.

[VladoB]

Many thanks Trurl,

 

but in general when I create share, like "Long Term Backup" or similar, simply for COLD data which are not expected to be modified often, should I ever tick for that share that I do want to use cache?

 

Should I use cache for any Data shares at all?

 

many thanks for your answer

 

V

[trurl]

Your original question was about dockers, and my answers to that still apply. But more generally...

 

The original purpose of cache was to allow faster writes to the server. Since cache isn't part of the parity array, it doesn't incur the performance penalty of parity updates when writing. Then later at a scheduled time, those cached files are moved to the parity protected array. While still on cache these files are not protected, unless you have a redundant cache pool. This is the way things work for user shares set to cache-yes.

 

I don't cache writes to most of my shares since they are mostly written to by unattended processes such as queued downloads or scheduled backups. So I don't care if they take a little longer to write since I am not waiting on them anyway. And since they are written directly to the parity array, they are protected. I set these shares to cache-no.

 

I do have some shares which I keep on cache (cache-prefer). Dockers working storage (appdata) for example. I don't run any VMs. I also have some shares with a copy of a subset of my music and photos. This is so other things on the network can easily and frequently access them without spinning up disks. Screensavers and music streaming devices for example. And I keep my DVR files as cache-prefer also since there is some performance benefit which makes it better for recording and streaming at the same time from these. Anything I might record and keep for the long term I later move to one of my cache-no shares.

 

So, whether and how you use cache for general purpose user shares is up to you.

 

There are some other, not necessarily obvious aspects to the various cache settings. See this FAQ for more:

 

https://lime-technology.com/forums/topic/46802-faq-for-unraid-v6/?page=2#comment-537383

 

[kizer]

I on the other hand I do some video encoding so when I send a video to my machine I typically run it thru HandBrake so I have a Modified version of it and the Original. I utilize the speed of the SSD and reduce the need to spin up any of my drives to do any thing. I also have a Photo Share to which I send items directly to the array any to another drive using Unassigned Devices for a removable backup. 

 

Honestly its all about your work flow. I'd just simply ask yourself what does each of your shares need to do and address each one independently and set them up accordingly.  

 

[VladoB]

Thanks a lot friends for your explanations

Vladimir