Cisco的Flash卡在刪除裡面的檔後
沒有馬上釋放出空間
必須再使用squeeze的指令
才會釋放空間，但這個指令在後期的版本才有
如果沒有的話，那就erase吧

#squeeze slot1:
Flash card inserted. Reading filesystem…done.

Squeeze operation may take a while. Continue? [confirm]
squeeze in progress… eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Rebuild file system directory…
Squeeze of slot1 complete