Why DOMAINS in USER path?

[opentoe]

A while ago I was told to put my VDISKS and image files that will be used a lot on a single drive rather then the array. I'm wondering why the default DOMAINS path is /mnt/user/domains.  Doesn't this path use the entire array and would make an VM operating system run slower? Would it be wise if I moved my VDISKS and IMAGES to like my cache drive or UNASSIGNED drive or something?

 

 

I also now have a /mnt/USER0 path that wasn't put there by me.

 

[bonienl]

"domains" is the name of a share, which should have been automatically created by Unraid with the setting "cache prefer".

This setting means the share exists on cache, if cache is present and otherwise it exists on the array.

 

If you added cache after creation of this share, you need to stop the docker service and run a manual move action to let the share to be moved completely to the cache (same applies to VMs)

[opentoe]

On 1/27/2020 at 1:40 AM, bonienl said:

"domains" is the name of a share, which should have been automatically created by Unraid with the setting "cache prefer".

This setting means the share exists on cache, if cache is present and otherwise it exists on the array.

 

If you added cache after creation of this share, you need to stop the docker service and run a manual move action to let the share to be moved completely to the cache (same applies to VMs)

When I go to install the MACINABOX docker there is a line for VM Image locations. The default is /mnt/user/domains  which uses the entire array. I would assume most people change this to an unassigned drive or cache only. Because once you change that default path this particular docker will not work properly until the XML file is edited. How can I keep the path /mnt/user/domains but only make sure anything written to that path is writing to the cache drive only? When I added the share DOMAINS I did select CACHE ONLY. The real path is /mnt/cache/domains.

 

 

[Xaero]

28 minutes ago, opentoe said:

When I go to install the MACINABOX docker there is a line for VM Image locations. The default is /mnt/user/domains  which uses the entire array. I would assume most people change this to an unassigned drive or cache only. Because once you change that default path this particular docker will not work properly until the XML file is edited. How can I keep the path /mnt/user/domains but only make sure anything written to that path is writing to the cache drive only? When I added the share DOMAINS I did select CACHE ONLY. The real path is /mnt/cache/domains.

 

 

You are misunderstanding the layered nature of the filesystem.
So unraid has 3 layers that get sandwiched together:
Raw volumes:
`/mnt/disk##`

 

Which all get sandwiched together into the parity array:
`/mnt/user0`

 

And Cache:
`/mnt/cache`

 

Which get's sandwiched into the user share volume
`/mnt/user`

The SHFS uses logic to determine whether or not data should be written to a spinning platter or the cache. The samba server always references /mnt/user since it contains all data both data on and off the cache. The /mnt/user/domains folder exists as /mnt/cache/domains as well.

The domains share being set to cache only will prevent SHFS from moving any data from cache to the parity array.

Edited January 30, 2020 by Xaero

[opentoe]

Ok, something clicked. Let me know if this is correct.

 

Since I created the share DOMAINS and ONLY selected to use the cache drive even though I enter the path /mnt/cache/domains it will always write to the cache drive because that's what the share is configured as. Regardless if it is in the user path or not.

 

 

[Xaero]

Correct, and the data will show up in both locations because User is a merged filesystem of User0 (parity array) and Cache (cache)

This way you can (for example) have a complete set of data, with small files that are frequently read/write on the cache SSD next to files that are large sequential reads or writes or hardly get used on the platters. The OS is none the wiser to the fact that the files are physically located two different places.