/usr/nagios/libexec/check_disk -w 20 -c 10 -p /dev/sda3 
DISK CRITICAL - free space: /dev 9 MB (98% inode=99%);| /dev=0MB;-10;0;0;10

df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2             445G   48G  398G  11% /
udev                   10M  152K  9.9M   2% /dev
/dev/sda1             149M   38M  112M  26% /boot
none                 1013M     0 1013M   0% /dev/shm


strace /usr/nagios/libexec/check_disk -w 20 -c 10 -p /dev/sda3

execve("/usr/nagios/libexec/check_disk", ["/usr/nagios/libexec/check_disk", "-w", "20", "-c", "10", "-p", "/dev/sda3"], [/* 29 vars */]) = 0
brk(0)                                  = 0x8051000
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f88000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=25337, ...}) = 0
mmap2(NULL, 25337, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7f81000
close(3)                                = 0
open("/lib/libc.so.6", O_RDONLY)        = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0JY\1\000"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=1221888, ...}) = 0
mmap2(NULL, 1181116, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb7e60000
mmap2(0xb7f7b000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x11b) = 0xb7f7b000
mmap2(0xb7f7e000, 9660, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb7f7e000
close(3)                                = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7e5f000
set_thread_area({entry_number:-1 -> 6, base_addr:0xb7e5f6b0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0
mprotect(0xb7f7b000, 4096, PROT_READ)   = 0
mprotect(0xb7fa4000, 4096, PROT_READ)   = 0
munmap(0xb7f81000, 25337)               = 0
brk(0)                                  = 0x8051000
brk(0x8072000)                          = 0x8072000
open("/etc/mtab", O_RDONLY)             = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=328, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f87000
read(3, "/dev/sda2 / reiserfs rw,noatime,"..., 4096) = 328
read(3, "", 4096)                       = 0
close(3)                                = 0
munmap(0xb7f87000, 4096)                = 0
stat64("/dev/sda3", {st_mode=S_IFBLK|0660, st_rdev=makedev(8, 3), ...}) = 0
statfs("/dev", {f_type=0x1021994, f_bsize=4096, f_blocks=2560, f_bfree=2522, f_bavail=2522, f_files=223760, f_ffree=223011, f_fsid={0, 0}, f_namelen=255, f_frsize=4096}) = 0
fstat64(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f87000
write(1, "DISK CRITICAL - free space: /dev"..., 76DISK CRITICAL - free space: /dev 9 MB (98% inode=99%);| /dev=0MB;-10;0;0;10
) = 76
exit_group(2)                           = ?
Process 28379 detached