O SQUID no FreeBSD 6.x e 7.x, versão 2.6.x e 2.7.x começaram a apresentar um erro estranho, não era problema de hardware. O serviço ‘morria‘ com sinal 6.

pid 99376 (squid), uid 100: exited on signal 6 (core dumped)
pid 7499 (squid), uid 100: exited on signal 6 (core dumped)
pid 7508 (squid), uid 100: exited on signal 6 (core dumped)
pid 7517 (squid), uid 100: exited on signal 6 (core dumped)
pid 7561 (squid), uid 100: exited on signal 6 (core dumped)
pid 7570 (squid), uid 100: exited on signal 6 (core dumped)
pid 7581 (squid), uid 100: exited on signal 6 (core dumped)
pid 7592 (squid), uid 100: exited on signal 6 (core dumped)
pid 7612 (squid), uid 100: exited on signal 6 (core dumped)
pid 7621 (squid), uid 100: exited on signal 6 (core dumped)
pid 7630 (squid), uid 100: exited on signal 6 (core dumped)
pid 7674 (squid), uid 100: exited on signal 6 (core dumped)
pid 7683 (squid), uid 100: exited on signal 6 (core dumped)

Para resolver, editar o arquivo /boot/loader.conf e acrescentar os seguintes parâmetros:

kern.ipc.msgmnb=8192
kern.ipc.msgmni=40
kern.ipc.msgseg=512
kern.ipc.msgssz=64
kern.ipc.msgtql=2048

Será necessário um reboot no servidor para que as configurações tenha efeito.

Após a adição desses parâmetros o SQUID não mais apresentou falhas de segmentação