Total noob. Did I use the cache disk wrong?

[rendermaster]

I have 4x4TB drives (1 parity, 3 data) as my main storage array with a 120GB sata SSD for cache. I followed the basic setup instructions but even after a few days the cache drive is always completely full and my shares appdata, domains and system show as "unprotected". I've RTM a bit but I just don't see what I'm missing. 

 

(PS-why is blanking out the serial numbers of a disk something? I don't immediately see how that data could be a security issue, could someone enlighten me?)

 

 

 

[trurl]

4 minutes ago, rendermaster said:

(PS-why is blanking out the serial numbers of a disk something? I don't immediately see how that data could be a security issue, could someone enlighten me?)

I agree and it is annoying since serial number is the way Unraid keeps track of disk assignments and may ultimately be the only way we can make sense of which disks are being discussed especially if they get dropped from the array.

 

And they are in diagnostics anyway.

 

Attach diagnostics to your NEXT post in this thread.

 

[trurl]

8 minutes ago, rendermaster said:

120GB sata SSD for cache

That is going to be too small for caching user share writes. Might be enough for docker/VM shares appdata, domains, system.

 

8 minutes ago, rendermaster said:

appdata, domains and system show as "unprotected"

Any files on single disk pool such as your cache are unprotected. Not necessarily a bad thing, just something to be aware of. You will want backups of anything important and irreplaceable anyway. Parity is not a substitute.

[rendermaster]

9 hours ago, trurl said:

That is going to be too small for caching user share writes. Might be enough for docker/VM shares appdata, domains, system.

 

Any files on single disk pool such as your cache are unprotected. Not necessarily a bad thing, just something to be aware of. You will want backups of anything important and irreplaceable anyway. Parity is not a substitute.

Ahhh.... I see. Is there a recommend size for cache drive? I also have a 1TB m.2 drive in the system and a second 120GB sata drive available, although it's a different brand and age of the other 120GB. What is the best way to get VMs/Docker onto the flash storage? I only have one docker container running right now and I've noticed it doesn't save preferences, each time I launch the app it's like the first time it's run. I would like to use a few more docker apps and a VM at some point.

 

re: "Parity is not a substitute." Parity protects from a single disk failure, correct? I also understand that my server would be vulnerable to physical/geographic issues, fire, flood, theft and plan to eventually back up the entire server to Backblaze/glacier/something.  Doesn't the mover service copy the data from all pool devices to the array nightly? Thereby protecting from a single (pool or array) disk failure?

 

Diagnostics attached. I had to re-zip it after the download. If that causes a problem I can post again.

boxx-diagnostics-20230118-0642.zip

[trurl]

1 hour ago, rendermaster said:

Parity protects from a single disk failure, correct?

Many more common ways to lose data, including user error.

 

1 hour ago, rendermaster said:

mover service copy the data from all pool devices to the array

Depends on the Use cache setting for each user share. Typically you want appdata, domains, system shares to stay on fast pool (cache) so Docker/VM performance isn't impacted by slower parity array, and so array disks can spin down since these files are always open. And this is how you currently have these shares configured (default for these).

 

1 hour ago, rendermaster said:

I had to re-zip it after the download.

Why? Diagnostics are downloaded as a single zip file. If it appears to you that it is downloaded as multiple folders and files, it is because your browser or computer is automatically opening zip files. You should be able to find the original zip wherever your downloads go.

 

More about filling cache to follow

[trurl]

cache:prefer means prefer to keep this share on cache, and if anything overflows to the array, move to cache if it can.

 

^^^ This is the main reason you are filling cache. You have all your shares set to prefer cache.

 

To get a share moved from cache to array, it must be set to cache:yes.

 

  

12 minutes ago, trurl said:

Typically you want appdata, domains, system shares to stay on fast pool (cache) so Docker/VM performance isn't impacted by slower parity array, and so array disks can spin down since these files are always open. And this is how you currently have these shares configured (default for these).

 

 

 

[trurl]

Cache is completely full. Especially important to avoid filling btrfs or it might corrupt.

 

Each pool (cache) has a Minimum Free setting. You must set Minimum to larger than the largest file you expect to write to the pool. If it has less than Minimum, Unraid will choose an array disk instead (overflow) for cache:yes and cache:prefer shares.

 

Each user share also has a Minimum Free setting. You must set Minimum to larger than the largest file you expect to write to the share. If a disk has less than Minimum, Unraid will choose another array disk (if allowed by other settings).

 

Mover is intended for idle time. Default is daily in the middle of the night. It is impossible to move from fast pool to slow array as fast as you can write to fast pool. If you need to write more than can be cached, don't cache.

 

[trurl]

2 hours ago, rendermaster said:

I only have one docker container running right now and I've noticed it doesn't save preferences, each time I launch the app it's like the first time it's run.

Post docker run

[trurl]

2 hours ago, rendermaster said:

also have a 1TB m.2 drive in the system

This would be good for caching user share writes. Then you could create a separate and redundant fast pool for dockers/VMs to use with those 2x120G drives as btrfs raid1

[rendermaster]

2 hours ago, trurl said:

cache:prefer means prefer to keep this share on cache, and if anything overflows to the array, move to cache if it can.

 

^^^ This is the main reason you are filling cache. You have all your shares set to prefer cache.

 

To get a share moved from cache to array, it must be set to cache:yes.

 

  

 

 

 

THANK YOU. and thank you for answering with kindness when this is very much a RTM situation. I very much appreciate you help here. I was able to reassign the m.2 drive to the cache and the errors immediately cleared. and I'll put in that second SATA ssd after work today and build a new pool for docker/VMs.

Edited January 18, 2023 by rendermaster
words

[rendermaster]

2 hours ago, trurl said:

Many more common ways to lose data, including user error.

 

Why? Diagnostics are downloaded as a single zip file. If it appears to you that it is downloaded as multiple folders and files, it is because your browser or computer is automatically opening zip files. You should be able to find the original zip wherever your downloads go.

user error. hadn't really thought of that, but of course, with full read/write permissions to a share a user could just start deleting data

 

diagnostics file was because I use MacOS and safari on my laptop and wanted to get it done quickly. Was the file still functional?

[trurl]

9 hours ago, rendermaster said:

use MacOS and safari on my laptop

Did you look for the single zip file that was downloaded? Or does Mac not actually keep it and just leaves you with the unzipped contents?

[rendermaster]

It was because I was using Safari (better battery life on M1 hardware). Chrome and Firefox both give a normal zip file. Latest diagnostics attached. But I think I got everything sorted. Got docker and VMs setup on a pool of 2 120GB ssds and moved the cache to the 1TB m.2. It's all green lights and the fix common problems plugin also looks happy.

 

Thanks again for your quick response, kindness and help with this @trurl I'm looking forward to digging into unraid more; Home Assistant, network ad blocking and DNS filtering, windows VM for some older games, offsite backups and some personal cloud stuff.

boxx-diagnostics-20230119-0831.zip