duplicate / mirrored directories

[Hamby]

Having migrated from Drive Bender, each of the drives comprising my pool has the same directory structure, though the actual files appear only on 1 (or 2) disks. Is this mirrored directory structure also the way Drive Pool works, or can I remove the empty directories from the disks that don't contain the related files?

[Shane]

Short answer is basically yes to both: the basic concept of presenting multiple physical drives as a single virtual drive is the same but the implementation under the hood is different, so you technically can manually remove the empty directories if you have to for some reason.

If you have run into a situation where it's actually necessary (e.g. perhaps an issue involving programs that need to access the poolpart drives directly instead of via the pool drive and don't like empty directories for whatever reason) to remove the "empty" folders, keep in mind:

• if you remove them from all of the poolpart drives in which they appear you will be removing them from the pool as if you had deleted them from the pool drive (i.e. if you are using some kind of automated tool to remove empty folders from a poolpart drive, you will have to account for whether the tool is able to check the other poolpart drives to see whether a folder is empty or "empty").
• if you are using duplication then drivepool may recreate "empty" folders as necessary to meet the designated duplication level on its next consistency check.
• if files in a folder are later added/moved to a poolpart drive on which the relevant folder(s) don't exist anymore then it will incur the overhead of having to recreate the folder(s) before adding the files.
• it would be a good idea to tell drivepool to remeasure the pool afterwards (from the GUI, Manage Pool -> Re-measure...).

TLDR don't do it unless it's necessary. Hope that helps.