I want to shrink my windows partition, and windows does not allow to shrink more than a few GB. Can I access that bitlocker partition with GParted, parted or any other partitioning program?
Install Dislocker, which allows you to mount Bitlocker partitions under linux
Create an unencrypted device from that partition (if there is no bitlocker password set, omit it)
mkdir /tmp/bitlocker sudo dislocker /dev/<partition> -u<password> -- /tmp/bitlocker
Run gparted on this device
sudo gparted /tmp/bitlocker/dislocker-file
You resized now the filesystem in the bitlocker partition. Resizing the partition itsself may destroy it, so proceed carefully.
Get blocksize of your partition:
sudo parted /tmp/bitlocket/dislocker-file unit s print all
parted> unit s parted> print all # get partition number of the bitlocker partition parted> resizepart <n> <newsize + a decent amount>
Careful here: I resized my partition twice, the first time I left a couple GB, the second time I shrinked it to the actual filesystem size. While it was booting after the first time, it wasnt after the second.
The safe way is definitely to decrypt the partition by disabling bitlocker. Its easy to shrink it then.