Petit memento d'un scrip en bash (attention, non testé) pour découper un tgz :
'''
# Split TGZ
splitsize="10G"; fn="home.tar.gz"; pathtocompress="/home" # edit here
split -b ${splitsize} ${fn} "${fn}.part" # split an existing tgz file
tar -cvzf - ${pathtocompress} | split -b ${splitsize} - "${fn}.part" # or split while making tgz file..
cat "${fn}.part*" > "joined.${fn}" # join back the file
tar -xvzf "joined.${fn}" # decompress the file
'''