Server version: Apache/2.2.22 (Unix)

Server built:   Mar 28 2012 16:31:45
Server's Module Magic Number: 20051115:30
Server loaded:  APR 1.4.6, APR-Util 1.4.1
Compiled using: APR 1.4.6, APR-Util 1.4.1
Architecture:   64-bit
Server MPM:     Prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/prefork"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT="/opt/apache2"
 -D SUEXEC_BIN="/opt/apache2/bin/suexec"
 -D DEFAULT_PIDLOG="logs/httpd.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_LOCKFILE="logs/accept.lock"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="conf/mime.types"
 -D SERVER_CONFIG_FILE="conf/httpd.conf"

Php5.2.17. Using mod_php5 as a DSO module compiled

Problem:

On shared webhosting, a lot of apache2 process never stop or die and they waiting as long as apache2 restart.

Strace of one of theses process:

access("tmp/meta_cache.txt", F_OK)      = 0
getcwd("/home/exemple.com/htdocs"..., 4096) = 34
lstat("/var", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/home", {st_mode=S_IFDIR|0755, st_size=1715, ...}) = 0
lstat("/home/exemple.com", {st_mode=S_IFDIR|0755, st_size=16, ...}) = 0
lstat("/home/exemple.com/htdocs", {st_mode=S_IFDIR|0770, st_size=51, ...}) = 0
lstat("/home/exemple.com/htdocs/tmp", {st_mode=S_IFDIR|0777, st_size=51, ...}) = 0
lstat("/home/exemple.com/htdocs/tmp/meta_cache.txt", {st_mode=S_IFREG|0666, st_size=8901, ...}) = 0
lstat("/var", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/home", {st_mode=S_IFDIR|0755, st_size=1715, ...}) = 0
lstat("/home/exemple.com", {st_mode=S_IFDIR|0755, st_size=16, ...}) = 0
lstat("/home/exemple.com/htdocs", {st_mode=S_IFDIR|0770, st_size=51, ...}) = 0
lstat("/home/exemple.com/htdocs/tmp", {st_mode=S_IFDIR|0777, st_size=51, ...}) = 0
lstat("/home/exemple.com/htdocs/tmp/meta_cache.txt", {st_mode=S_IFREG|0666, st_size=8901, ...}) = 0
lstat("/var", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/home", {st_mode=S_IFDIR|0755, st_size=1715, ...}) = 0
lstat("/home/exemple.com", {st_mode=S_IFDIR|0755, st_size=16, ...}) = 0
getcwd("/home/exemple.com/htdocs"..., 4096) = 34
lstat("/var", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/var/www", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/home", {st_mode=S_IFDIR|0755, st_size=1715, ...}) = 0
lstat("/home/exemple.com", {st_mode=S_IFDIR|0755, st_size=16, ...}) = 0
lstat("/home/exemple.com/htdocs", {st_mode=S_IFDIR|0770, st_size=51, ...}) = 0
lstat("/home/exemple.com/htdocs/tmp", {st_mode=S_IFDIR|0777, st_size=51, ...}) = 0
lstat("/home/exemple.com/htdocs/tmp/meta_cache.txt", {st_mode=S_IFREG|0666, st_size=8901, ...}) = 0
open("/home/exemple.com/htdocs/tmp/meta_cache.txt", O_RDONLY) = 10905
fstat(10905, {st_mode=S_IFREG|0666, st_size=8901, ...}) = 0

lseek(10905, 0, SEEK_CUR)               = 0

flock(10905, LOCK_SH)                   =

The process never die, and stay like this. All files are on NFS V3

I'dont know how to solve this problem or find more informations. The effect is that all apache2 process become used and apache2 crash totaly .

Thanks for you help.