[solved] New server. cache doesn't work as it should

Recommended Posts



I installed a new Unraid server and set the share cache to Yes.
When I did the first file load, the copy failed and I got a warning that the cache disk was full.

In order to make the copy, I needed to invoke the move manually.

I repeated the same test using the share cache option as Yes and Prefer and the error was repeated.

The information I read in the manual is that with the Yes cache option, all new files and subdirectories are written to the cache, if there is enough free space in the cache. If there is insufficient cache space, new files and directories will be created in the array.


But in practice, this does not happen: When there is no space in the cache, the copy simply fails.


Is this a bug, it doesn't really work or am I doing something wrong?


This is a server to store videos I produce for Youtube and online courses. Usually these are 300Mb to 2Gb video and other smaller files for thumbs and mp3 files.
If this feature doesn't work, it would need to have a very large cache disk to be sufficient for file moves.
If I don't enable the cache, I noticed that writing is very slow.


the server is with
2 x 6Tb - parity disks
3 x 3tb - data discs
1 x 256gb ssd - cache disk






Edited by EduardoGula
Link to comment
9 minutes ago, EduardoGula said:

If there is insufficient cache space, new files and directories will be created in the array.

Unraid has no way to know how large a file will become when it chooses a disk for it. If cache has less than Minimum Free, Unraid will choose an array disk. You must set Minimum Free for cache to larger than the largest file you expect to write to cache. Each user share also has a Minimum Free setting that works in a similar manner. If a disk has less than Minimum, Unraid will choose another disk.


Link to comment
  • EduardoGula changed the title to [solved] New server. cache doesn't work as it should

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.