Linux unlimit

[root@jhoa ~]# ulimit  -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 38656
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 2047
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

-u 限制每个用户的进程
[root@jhoa ~]# ulimit -u 150

这个只是暂时生效,ulimit 是SESSION级别参数

1.会话级别生效

2.一个用户能使用的进程数

适用于命令登陆shell会话期间

[root@jhoa ~]# ulimit -u 
150


[root@jhoa ~]# ps -ef | grep root | wc -l
110

[root@jhoa ~]# ps -ef | wc -l
141


[oracle@jhoa ~]$ ps -ef | grep oracle | wc -l
-bash: fork: Resource temporarily unavailable
-bash: fork: Resource temporarily unavailable


[root@jhoa ~]# ps -ef | grep oracle | wc -l
30
------------------------------------------------
oracle               soft    nproc   100
oracle               hard    nproc   100
oracle               soft    nofile  1024
oracle               hard    nofile  65536

[oracle@jhoa ~]$ ulimit  -u
30
[oracle@jhoa ~]$ ps -ef | grep oracle | wc -l
-bash: fork: Resource temporarily unavailable
-bash: fork: Resource temporarily unavailable

[oracle@jhoa ~]$ ps -ef | grep oracle | wc -l
34

[oracle@jhoa ~]$ ps -ef | grep oracle
root      2790  2520  0 20:11 ?        00:00:00 sshd: oracle [priv]
oracle    2792  2790  5 20:11 ?        00:00:41 sshd: oracle@pts/1
oracle    2793  2792  0 20:11 pts/1    00:00:00 -bash
oracle    2901     1  0 20:12 ?        00:00:00 ora_pmon_orcl
oracle    2903     1  0 20:12 ?        00:00:00 ora_psp0_orcl
oracle    2905     1  0 20:12 ?        00:00:00 ora_mman_orcl
oracle    2907     1  0 20:12 ?        00:00:00 ora_dbw0_orcl
oracle    2909     1  0 20:12 ?        00:00:00 ora_lgwr_orcl
oracle    2911     1  0 20:12 ?        00:00:00 ora_ckpt_orcl
oracle    2913     1  0 20:12 ?        00:00:00 ora_smon_orcl
oracle    2915     1  0 20:12 ?        00:00:00 ora_reco_orcl
oracle    2917     1  0 20:12 ?        00:00:00 ora_cjq0_orcl
oracle    2919     1  0 20:12 ?        00:00:00 ora_mmon_orcl
oracle    2921     1  0 20:12 ?        00:00:00 ora_mmnl_orcl
oracle    2923     1  0 20:12 ?        00:00:00 ora_d000_orcl
oracle    2925     1  0 20:12 ?        00:00:00 ora_s000_orcl
oracle    2938     1  0 20:12 ?        00:00:00 ora_qmnc_orcl
oracle    2947     1  0 20:13 ?        00:00:00 ora_q001_orcl
oracle    2949     1  0 20:13 ?        00:00:00 ora_q002_orcl
oracle    2951     1  0 20:13 ?        00:00:00 ora_q003_orcl
root      3012  2830  0 20:15 pts/1    00:00:00 su - oracle
oracle    3013  3012  0 20:15 pts/1    00:00:00 -bash
root      3072  2520  0 20:16 ?        00:00:00 sshd: oracle [priv]
oracle    3074  3072  0 20:16 ?        00:00:00 sshd: oracle@pts/0
oracle    3075  3074  0 20:16 pts/0    00:00:00 -bash
root      3151  2520  0 20:16 ?        00:00:00 sshd: oracle [priv]
oracle    3153  3151 23 20:16 ?        00:01:38 sshd: oracle@pts/2
oracle    3154  3153  0 20:17 pts/2    00:00:00 -bash
root      3192  3112  0 20:17 pts/0    00:00:00 su - oracle
oracle    3193  3192  0 20:17 pts/0    00:00:00 -bash
oracle    3268  3154 46 20:21 pts/2    00:01:15 sh ./2.sh
oracle    3304  3193  0 20:23 pts/0    00:00:00 ps -ef
oracle    3305  3193  0 20:23 pts/0    00:00:00 grep oracle
[oracle@jhoa ~]$ ps -ef | grep oracle | wc -l
-bash: fork: Resource temporarily unavailable
-bash: fork: Resource temporarily unavailable