Now that SQLite issues seem to be fixed....help me understand...

[Rich Minear]

So when I was running my system on 6.6.7, had had my appdata located in /mnt/user/appdata.   I was told to move that to /mnt/disk1/appdata, which I did.  I've also been told that I should have it on a cache drive (I don't have a cache drive installed at all). 

 

I'm looking for some understanding... (understand...a bit of a noobie when it comes to Unraid, but not to raid systems, or Plex databases). 

 

What is the different  between putting appdata in a different location?  I had ZERO issues with /mnt/user/appdata under 6.6.7.  Should I put it back that way?

 

What are the reasons for having a cache drive when you do not do a lot of writing that requires faster access? 

 

 

[BRiT]

Part of it was to eliminate an entire layer. The /mnt/user/ runs through Fuse that runs in User space. Using /mnt/cache/ or /mnt/disk# bypasses that layer.

 

Using cache disk(s) allows all other array drives to spin down, while any reads and writes happen only on the cache drive(s).

[Squid]

5 hours ago, Rich Minear said:

So when I was running my system on 6.6.7, had had my appdata located in /mnt/user/appdata.   I was told to move that to /mnt/disk1/appdata, which I did.

By leaving it on /mnt/disk1, you will get moderately better performance from your apps.

[John_M]

5 hours ago, Rich Minear said:

What are the reasons for having a cache drive when you do not do a lot of writing that requires faster access? 

The cache drive's original purpose of mitigating slow writes to the parity protected array has been largely superseded by the introduction of "Turbo-write", so it's main use now is for the storage of things like Plex databases, application data for other docker containers, the docker.img file itself,  and vdisk images for VMs, all of which benefit greatly from the speed of an SSD, while allowing the array to be used for bulk storage.

[John_M]

Having you application data located at /mnt/user/appdata has the advantage of working (unforeseen and obscure bugs notwithstanding) whether you have a cache disk or not, so it's a good compromise choice for the default path.

[Rich Minear]

So with a cache drive...if I move my appdata to it, is there any redundancy?  Can I add two ssd's and have them be mirrored or anything like that?

[Hoopster]

49 minutes ago, Rich Minear said:

So with a cache drive...if I move my appdata to it, is there any redundancy?  Can I add two ssd's and have them be mirrored or anything like that?

Yes, you can create btrfs cache pools of two or more cache drives.  The default is RAID 1 (mirror) but there are other possibilities as well.