I got the following error message on top of the package creation box in WHM. (WHM > Add packages)

[an error occurred while processing this directive]

Error log (tail /usr/local/cpanel/logs/error_log) shows

[2014-06-02 07:07:01 +0000] warn [Internal Warning while parsing [stdin] 748029] Failed to write lock file: /etc/ipaddrpool.lock: at /usr/local/cpanel/Cpanel/SafeFileLock.pm line 17.
Cpanel::SafeFileLock::new('Cpanel::SafeFileLock', '/etc/ipaddrpool.lock', 'GLOB(0x503a7c0)') called at /usr/local/cpanel/Cpanel/SafeFile.pm line 128
Cpanel::SafeFile::safelock('/etc/ipaddrpool') called at /usr/local/cpanel/Cpanel/SafeFile.pm line 235
Cpanel::SafeFile::_safe_open('GLOB(0x470b320)', '<', '/etc/ipaddrpool', 'CODE(0x29f33b0)', 'safeopen') called at /usr/local/cpanel/Cpanel/SafeFile.pm line 32

I had rebooted the server and also run fixquotas

root@serverxx [/scripts]# ./fixquotas
Installing Default Quota Databases......Done
Quota Mode: Linux
journaled quota support: kernel supports, user space tools supports (available)
checking out /backup
checking out /backup
Failed to write lock file: /etc/fstab.lock: Bad file descriptor at /usr/local/cpanel/Cpanel/SafeFileLock.pm line 17.
Failed to write lock file: /etc/fstab.lock: Bad file descriptor at /usr/local/cpanel/Cpanel/SafeFileLock.pm line 17.

root@serverxx [/]# df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/sda5 640K 640K 0 100% /
tmpfs 979K 3 979K 1% /dev/shm
/dev/sda1 26K 44 26K 1% /boot
/dev/sda8 55M 3.6M 52M 7% /home
/dev/sda7 64K 3.5K 61K 6% /tmp
/dev/sda2 1.3M 181K 1.1M 15% /usr
/dev/sda3 1.3M 449K 832K 36% /var
/dev/sdb1 59M 4.2M 55M 8% /backup

Following are the results of disk space usage.

root@serverxx [/etc]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 9.9G 8.1G 1.3G 87% /
tmpfs 3.9G 4.0K 3.9G 1% /dev/shm
/dev/sda1 99M 85M 9.1M 91% /boot
/dev/sda8 863G 243G 577G 30% /home
/dev/sda7 1008M 73M 884M 8% /tmp
/dev/sda2 20G 14G 5.1G 73% /usr
/dev/sda3 20G 8.4G 11G 45% /var
/dev/sdb1 917G 310G 561G 36% /backup

I checked files in /mnt/root/.cpanel/comet/channels by ls -LR|wc -l

# ls -LR|wc -l
421798

There appears to be a comet scripting for certain cpanel functions, mainly related to WHM email area functions.

I run following command to clean up some files, that will remove all files in this directory that have not been accessed in more than three days.

/usr/local/cpanel/bin/purge_dead_comet_files

Problem fixed and Cpanel account creation working properly.