More graceful handling of running out of space on one drive (with a lot more space on other drives)

[m00nman]

I just moved from regular linux + mergerfs to unraid and was surprised to learn that there is no graceful handling of running out of space on one of the drives if a file doesn't fit on the drive. For example with 3GB of free space on Drive1, if you try to 'cp' a file that's 4GB in size to the share, it will start copying the file until Drive1 fill up and will then throw an out of space error without trying to put the same file on Drive2 with (let's say) 1TB of free space.

There is minimum free space option in share options, but 1. it wastes space that could be used for smaller files 2. it's hard to predict the maximum file size that could go in this share.

 

Mergerfs has a mount option:

Quote

moveonenospc=BOOL|POLICY: When enabled if a write fails with ENOSPC (no space left on device) or EDQUOT (disk quota exceeded) the policy selected will run to find a new location for the file. An attempt to move the file to that branch will occur (keeping all metadata possible) and if successful the original is unlinked and the write retried. (default: false, true = mfs)

 

which never gave me any issues and happened completely transparently in the background. I was able to fill up the drive with smaller files, while bigger files would get moved to the other drive with more free space. I'm hoping it could be implemented in unraid.

Edited October 28, 2022 by m00nman