Необычно долгий запуск программ на linux

[Jaguar77]

первый сервер :

model name : Genuine Intel® CPU 2140 @ 1.60GHz

cpu MHz : 1803.502

kernel = 2.6.32-279.19.1.el6.centos.plus.x86_64

диск -raid mirror

 

Тут всё отлично, например программа пинг запускается за 0.1 секунды.

[root@localhost ~]# perf stat -B ping
Usage: ping [-LRUbdfnqrvVaA] [-c count] [-i interval] [-w deadline]
           [-p pattern] [-s packetsize] [-t ttl] [-I interface or address]
           [-M mtu discovery hint] [-S sndbuf]
           [ -T timestamp option ] [ -Q tos ] [hop1 ...] destination

Performance counter stats for 'ping':

         1.153553 task-clock                #    0.059 CPUs utilized
                5 context-switches          #    0.004 M/sec
                0 cpu-migrations            #    0.000 K/sec
              176 page-faults               #    0.153 M/sec
        1,963,958 cycles                    #    1.703 GHz                     [11.64%]
  <not supported> stalled-cycles-frontend
  <not supported> stalled-cycles-backend
          739,595 instructions              #    0.38  insns per cycle         [36.36%]
          124,986 branches                  #  108.349 M/sec                   [97.81%]
            9,514 branch-misses             #    7.61% of all branches

      0.019669241 seconds time elapsed

[root@localhost ~]# hdparm -tT /dev/md0p1
/dev/md0p1:

Timing cached reads:   2010 MB in  2.00 seconds = 1005.17 MB/sec
Timing buffered disk reads:  220 MB in  3.02 seconds =  72.89 MB/sec

 

 

второй сервер :

model name : Quad-Core AMD Opteron Processor 2376

cpu MHz : 2300.088

kernel = 2.6.32-431.5.1.el6.centos.plus.x86_6

диск = raid 5

 

А вот тапример такая команда за 1.2 секунды :

 

time ls -l /var
total 72
real    0m1.263s
user    0m0.003s
sys     0m0.000s

Ping запускается за 0.6 секунды.

[root@localhost ~]# perf stat -B ping
Usage: ping [-LRUbdfnqrvVaA] [-c count] [-i interval] [-w deadline]
           [-p pattern] [-s packetsize] [-t ttl] [-I interface or address]
           [-M mtu discovery hint] [-S sndbuf]
           [ -T timestamp option ] [ -Q tos ] [hop1 ...] destination

Performance counter stats for 'ping':

         0.518551 task-clock                #    0.001 CPUs utilized
                1 context-switches          #    0.002 M/sec
                1 cpu-migrations            #    0.002 M/sec
              169 page-faults               #    0.326 M/sec
          841,000 cycles                    #    1.622 GHz
          328,760 stalled-cycles-frontend   #   39.09% frontend cycles idle
          395,869 stalled-cycles-backend    #   47.07% backend  cycles idle
          752,300 instructions              #    0.89  insns per cycle
                                            #    0.53  stalled cycles per insn
          157,792 branches                  #  304.294 M/sec                   [27.97%]
    <not counted> branch-misses

[root@localhost ~]# hdparm -tT /dev/md1

/dev/md1:
Timing cached reads:   6998 MB in  2.00 seconds = 3500.39 MB/sec
Timing buffered disk reads: 752 MB in  3.00 seconds = 250.66 MB/sec
   0.622642614 seconds time elapsed

 

Почему могут быть такие тормоза ??

[alexmern]

 Timing buffered disk reads: 752 MB in  3.00 seconds = 250.66 MB/sec

[Jaguar77]

проблемму решил обновлением драйверов. скачал LinuxMPT_SAS_RHEL5-6_SLES10-11_PH21-4.28.00 , скомпилил, установил и всё заработало.