I tried many times to force dedup work on my existing 20H2/19041 build (and 20H1 too) and nothing helped - there were errors after second mounting. Now I created virtual machine with 1909 windows and mount/maintain my large deduped VHDX inside it as it is mounted natively by Hyper-V. Drive is shared via SMB and can be reached from host system. Normally it consumes only 1-2GB RAM when it is launched to let me use my deduped drive when I need it. It is acceptable tradeoff as for me.
Recently getting an issue where my drive will refuse to optimize or pretty much do any dedup job other than unoptimize, claims the filesystem is possibly damaged with a 0x8056530E error code. I checked the filesystem multiple times and there is no damage but the system still refuses to do anything. Anyone have any ideas?
So, it's rather obvious to do, but still thought I'd post it. This is what I have running now, and it causes me to be able to use dedup almost as normal. I've placed a .ps1 file somewhere on my computer with these contents: Remove-Item "D:\System Volume Information\Dedup\Settings\HSM.00.CFG" Remove-Item "D:\System Volume Information\Dedup\Settings\HSM.01.CFG" Enable-DedupVolume -Volume D: -DataAccess Now, go to Task Scheduler and schedule a task when you login. Make sure you select Run as "SYSTEM". Reference the .ps1 file. I've also tinkered a bit with delaying it on startup. This causes the access to the volume to be available within a minute after logging in. Thanks to terminx for finding this workaround.