Hello,

Currently my setup has 3 drives in Array, and ideally I want to control what goes to what drive.

At first I had disk shares enabled, and that works well.

Now managed to add cache, and it seems that there is no way to move cache to disk shares.

Am I right that in above setup more optimal way would be?:

• make user shares for each drive.

• configure shares to access particular disk. (Share1 -> Include DISK1, 2 -> 2,...)

• add cache mover for each, so data from cache is moved to according disk over time.

In the User Share Setting:

First Shares from GUI. Then chose the User Share (2). Then (3) using "Include disk(s):" or "Excluded disk(s):" (NOT both!) to chose where the files are to be placed.

Yea, I did configured like this, here I asked if I'm on right path or this has drawbacks and maybe better ways there are.

Not that I ever heard of...

User Shares are definitely the way to go. And after you get your user shares configured, I recommend you NOT share disks on the network.

1 minute ago, trurl said:

User Shares are definitely the way to go. And after you get your user shares configured, I recommend you NOT share disks on the network.

Will leave disk shares available, just hidden.

Because for example cache is 240GB, and if I push 1TB single file to user share which is has CACHE->ARRAY setup, it starts to place file into cache.

I dont think it will end well.

ChatGPT said that it will avoid cache if file exceeds cache, but reality shows different story. Not first time when I doubt AI responses, and those are actually wrong.

Edited March 21Mar 21 by apx

You must never mix disks and user shares when copying/moving files.

Just now, apx said:

Because for example cache is 240GB, and if I push 1TB single file to user share which is has CACHE->ARRAY setup, it starts to place file into cache.

I dont think it will end well.

Not a problem if you set Minimum Free for cache

https://docs.unraid.net/unraid-os/using-unraid-to/manage-storage/cache-pools/#minimum-free-space-for-a-cache-pool

And for each user share

https://docs.unraid.net/unraid-os/using-unraid-to/manage-storage/shares/#minimum-free-space

And, if you expect to write more at one time than cache can hold, don't cache.

But whatever you do

5 minutes ago, trurl said:

You must never mix disks and user shares when copying/moving files.

Linux doesn't know that user shares are just another view of disks/pools, so it will allow you to specify the same file as source and destination. It creates a new empty file at the destination, then the source file is empty because they are the same file.

TLDR.

If cache is 240, and I have single files bigger than that.

What minimum free space should be set, so smaller files go onto SSD, and exceeding ones - skip cache. Shall I set there 200GB?

Or plain simple, those huge copies should be done directly to disk, so it avoid cache entirely ? (I like this option more)

In that scenario, a normally reasonable Minumum Free wouldn't work, so don't cache.

Even if you did set it to 200, if cache had more than 200 free, it would choose cache because it has more than Minimum Free. It doesn't consider how large the file you will write will become.

Are you really writing single files larger than cache?

Yea, there are even TB big backup files.
Will stick for those cases - direct disk paths.

A user share doesn't have to use cache at all.

Just now, apx said:

Yea, there are even TB big backup files.
Will stick for those cases - direct disk paths.

No, No NO!!!! You safest choice is not to cache that share! You are in the grasp of a catch-22 situation. Don't make things worst be setting things up so that one little bit of cockpit error will result in data loss!

Edited March 21Mar 21 by Frank1940

Then probably I made fine choice.

Those huge files are mainly from backups.

If that user share includes more than one array disk, it might even be difficult to choose a Minimum Free for the share. If a disk has less than Minimum Free, it will choose another disk. Conversely, if a disk has more than Minimum Free, it can choose the disk even if the file will not fit.

I also have a Backup share which is the destination for backup disk images from other computers on the network. It only includes one array disk, and doesn't use cache.