Growfs

growfs увеличить раздмер раздела In fact, you can only increase the size of  the file system.

tunefs -p /dev/ad8s1a tunefs: ACLs: (-a)                                        disabled tunefs: MAC multilabel: (-l)                              disabled tunefs: soft updates: (-n)                                disabled tunefs: gjournal: (-J)                                    disabled tunefs: maximum blocks per file in a cylinder group: (-e) 2048 tunefs: average file size: (-f)                           16384 tunefs: average number of files in a directory: (-s)      64 tunefs: minimum percentage of free space: (-m)            8% tunefs: optimization preference: (-o)                     time tunefs: volume label: (-L)

Размер slice можно увелить посредством fdisk - If you simply make the existing slice larger without modifying its start offset, your file systems should be ok.