can it be a reason

[Wojciech Puchar]

of server reboots?

tunefs: ACLs: (-a)                                         disabled
tunefs: MAC multilabel: (-l)                               disabled
tunefs: soft updates: (-n)                                 enabled
tunefs: maximum blocks per file in a cylinder group: (-e)  512
tunefs: average file size: (-f)                            16384
tunefs: average number of files in a directory: (-s)       64
tunefs: minimum percentage of free space: (-m)             0%

^^^^^^

tunefs: optimization preference: (-o)                      space
tunefs: volume label: (-L)



i used -m 0 willingly, because it's squid storage and i control the space 
used in squid config so it's actually 8-10% free all the time.