This script i'm using on my flash drive with gentoo

Usage

• -u — Enter users (separated by commas. Example: user1,user2,etc)
• -d — Directory for user data files (for *.tar.xz. Default: /var/lib/u2tmpfs)
• -U — Create/Update all *.tar.xz
• -s — tmpfs size option (Example: 512M, 4G. Default: 512M; Warning: you can use only half of installed RAM!)
• -o — Use the specified mount options for tmpfs (Default: "mode=755,noatime")
• -w — Wipe user data on USER_DATA_DIR for current USER (-u user1)

Example

1. Only init/update all users data without mounting tmpfs "mount -t tmpfs ...":

u2tmpfs -u user1,user2 -d /var/lib/u2tmpfs -U

2. Mount users home dir to tmpfs and extract all users data:

u2tmpfs -u user1,user2