How to Repair Corrupted rc.conf file

Procedure on how to solve FreeBSD boot up problem with the error message:

Loading configuration files.
/etc/rc.conf:51 Syntax error: Unterminated quoted string
Enter full pathname of Shell or RETURN for /bin/sh:

This error is normally encountered if there is a misplaced or missing double quote in the configuration file of the FreeBSD installation.
Sample invalid rc.conf file:

usbd_enable=”YES
dbus_enable=”YES”
compat5x_enable=”YES”

Note that there is a missing double quote in the example above. This error may also be triggered by a misplaced or unnecessary double quote in the configuration file.
To fix this problem:

1. (Optional) Reboot your FreeBSD and select the login option:
4. Boot FreeBSD in single user mode This can by done by pressing the number 4 upon boot up.

mpt0: QUEUE FULL EVENT: Bus 0×00 Target 0×08 Depth 128

proxy# dmesg |grep mpt

mpt0: <LSILogic SAS/SATA Adapter> port 0×4000-0x40ff mem 0xd8610000-0xd8613fff,0xd8600000-0xd860ffff irq 25 at device 3.0 on pci5
mpt0: [ITHREAD]
mpt0: MPI Version=1.5.13.0
mpt0: Capabilities: ( RAID-0 RAID-1E RAID-1 )
mpt0: 0 Active Volumes (2 Max)
mpt0: 0 Hidden Drive Members (10 Max)
da0 at mpt0 bus 0 target 8 lun 0
da1 at mpt0 bus 0 target 9 lun 0

Scenario: Performed a clean install of FreeBSD 7.1-STABLE with a SAS RAID controller, which completed without errors. After rebooting and beginning to install packages, I started seeing the following error: mpt0: QUEUE FULL EVENT: Bus 0×00 Target 0×08 Depth 128.

Solution: Searching online indicated that the problem was with support for Tagged Command Queuing in the mpt driver. The output of camcontrol was: