JVM虚拟机宕机_java.lang.OutOfMemoryError: unable to create new native thread

原因：当前用户的系统最最大程序数数已达到最大值，使用ulimit -u可以看到是1024

解决办法：在当前用户下使用ulimit -u 65535

然后再执行jsp，一切ok

功能说明：控制shell程序的资源。
语　　法：ulimit [-aHS][-c <core文件上限>][-d <数据节区大小>][-f <文件大小>][-m <内存大小>][-n <文件数目>][-p <缓冲区大小>][-s <堆叠大小>][-t <CPU时间>][-u <程序数目>][-v <虚拟内存大小>]
补充说明：ulimit为shell内建指令，可用来控制shell执行程序的资源。

使用jps报错如下：

Error occurred during initialization of VM
java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Thread.java:714)
at java.lang.ref.Reference.<clinit>(Reference.java:162)

详细日志见code：

内容：
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Cannot create GC thread. Out of system resources.
# Possible reasons:
#   The system is out of physical RAM or swap space
#   In 32 bit mode, the process size limit was hit
# Possible solutions:
#   Reduce memory load on the system
#   Increase physical memory or swap space
#   Check if swap backing store is full
#   Use 64 bit Java on a 64 bit OS
#   Decrease Java heap size (-Xmx/-Xms)
#   Decrease number of Java threads
#   Decrease Java thread stack sizes (-Xss)
#   Set larger code cache with -XX:ReservedCodeCacheSize=
# This output file may be truncated or incomplete.
#
#  Out of Memory Error (gcTaskThread.cpp:46), pid=25470, tid=140583204763392
#
# JRE version:  (7.0_76-b13) (build )
# Java VM: Java HotSpot(TM) 64-Bit Server VM (24.76-b04 mixed mode linux-amd64 compressed oops)
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
 
---------------  T H R E A D  ---------------
 
Current thread (0x00007fdc0c008800):  JavaThread "Unknown thread" [_thread_in_vm, id=25471, stack(0x00007fdc13eb3000,0x00007fdc13fb4000)]
 
Stack: [0x00007fdc13eb3000,0x00007fdc13fb4000],  sp=0x00007fdc13fb2540,  free space=1021k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x9a32ba]  VMError::report_and_die()+0x2ea
V  [libjvm.so+0x497f7b]  report_vm_out_of_memory(char const*, int, unsigned long, char const*)+0x9b
V  [libjvm.so+0x5584ba]  GCTaskThread::GCTaskThread(GCTaskManager*, unsigned int, unsigned int)+0x11a
V  [libjvm.so+0x557a38]  GCTaskManager::initialize()+0x2b8
V  [libjvm.so+0x8417f8]  ParallelScavengeHeap::initialize()+0x6f8
V  [libjvm.so+0x97518a]  Universe::initialize_heap()+0xca
V  [libjvm.so+0x976359]  universe_init()+0x79
V  [libjvm.so+0x5b1d25]  init_globals()+0x65
V  [libjvm.so+0x95dc4d]  Threads::create_vm(JavaVMInitArgs*, bool*)+0x1ed
V  [libjvm.so+0x639fe4]  JNI_CreateJavaVM+0x74
C  [libjli.so+0x2f8e]  JavaMain+0x9e
 
 
---------------  P R O C E S S  ---------------
 
Java Threads: ( => current thread )
 
Other Threads:
 
=>0x00007fdc0c008800 (exited) JavaThread "Unknown thread" [_thread_in_vm, id=25471, stack(0x00007fdc13eb3000,0x00007fdc13fb4000)]
 
VM state:not at safepoint (not fully initialized)
 
VM Mutex/Monitor currently owned by a thread: None
 
GC Heap History (0 events):
No events
 
Deoptimization events (0 events):
No events
 
Internal exceptions (0 events):
No events
 
Events (0 events):
No events
 
 
Dynamic libraries:
00400000-00401000 r-xp 00000000 08:02 9961723                            /usr/local/jdk1.7.0_76/bin/jstat
00600000-00601000 rw-p 00000000 08:02 9961723                            /usr/local/jdk1.7.0_76/bin/jstat
00ef2000-00f13000 rw-p 00000000 00:00 0                                  [heap]
80000000-81500000 rw-p 00000000 00:00 0 
81500000-85200000 rw-p 00000000 00:00 0 
85200000-85780000 rw-p 00000000 00:00 0 
85780000-581b00000 rw-p 00000000 00:00 0 
581b00000-581f00000 rw-p 00000000 00:00 0 
581f00000-800000000 rw-p 00000000 00:00 0 
3d56400000-3d56420000 r-xp 00000000 08:02 3932555                        /lib64/ld-2.12.so
3d5661f000-3d56620000 r--p 0001f000 08:02 3932555                        /lib64/ld-2.12.so
3d56620000-3d56621000 rw-p 00020000 08:02 3932555                        /lib64/ld-2.12.so
3d56621000-3d56622000 rw-p 00000000 00:00 0 
3d56800000-3d56802000 r-xp 00000000 08:02 3932558                        /lib64/libdl-2.12.so
3d56802000-3d56a02000 ---p 00002000 08:02 3932558                        /lib64/libdl-2.12.so
3d56a02000-3d56a03000 r--p 00002000 08:02 3932558                        /lib64/libdl-2.12.so
3d56a03000-3d56a04000 rw-p 00003000 08:02 3932558                        /lib64/libdl-2.12.so
3d56c00000-3d56d8b000 r-xp 00000000 08:02 3932556                        /lib64/libc-2.12.so
3d56d8b000-3d56f8a000 ---p 0018b000 08:02 3932556                        /lib64/libc-2.12.so
3d56f8a000-3d56f8e000 r--p 0018a000 08:02 3932556                        /lib64/libc-2.12.so
3d56f8e000-3d56f8f000 rw-p 0018e000 08:02 3932556                        /lib64/libc-2.12.so
3d56f8f000-3d56f94000 rw-p 00000000 00:00 0 
3d57000000-3d57017000 r-xp 00000000 08:02 3932563                        /lib64/libpthread-2.12.so
3d57017000-3d57217000 ---p 00017000 08:02 3932563                        /lib64/libpthread-2.12.so
3d57217000-3d57218000 r--p 00017000 08:02 3932563                        /lib64/libpthread-2.12.so
3d57218000-3d57219000 rw-p 00018000 08:02 3932563                        /lib64/libpthread-2.12.so
3d57219000-3d5721d000 rw-p 00000000 00:00 0 
3d57400000-3d57407000 r-xp 00000000 08:02 3932564                        /lib64/librt-2.12.so
3d57407000-3d57606000 ---p 00007000 08:02 3932564                        /lib64/librt-2.12.so
3d57606000-3d57607000 r--p 00006000 08:02 3932564                        /lib64/librt-2.12.so
3d57607000-3d57608000 rw-p 00007000 08:02 3932564                        /lib64/librt-2.12.so
3d57800000-3d57883000 r-xp 00000000 08:02 3932279                        /lib64/libm-2.12.so
3d57883000-3d57a82000 ---p 00083000 08:02 3932279                        /lib64/libm-2.12.so
3d57a82000-3d57a83000 r--p 00082000 08:02 3932279                        /lib64/libm-2.12.so
3d57a83000-3d57a84000 rw-p 00083000 08:02 3932279                        /lib64/libm-2.12.so
7fdc033ac000-7fdc035f4000 rw-p 00000000 00:00 0 
7fdc035f4000-7fdc035f5000 ---p 00000000 00:00 0 
7fdc035f5000-7fdc036f5000 rw-p 00000000 00:00 0 
7fdc036f5000-7fdc036f6000 ---p 00000000 00:00 0 
7fdc036f6000-7fdc037f6000 rw-p 00000000 00:00 0 
7fdc037f6000-7fdc037f7000 ---p 00000000 00:00 0 
7fdc037f7000-7fdc038f7000 rw-p 00000000 00:00 0 
7fdc038f7000-7fdc038f8000 ---p 00000000 00:00 0 
7fdc038f8000-7fdc039f8000 rw-p 00000000 00:00 0 
7fdc039f8000-7fdc039f9000 ---p 00000000 00:00 0 
7fdc039f9000-7fdc03af9000 rw-p 00000000 00:00 0 
7fdc03af9000-7fdc03afa000 ---p 00000000 00:00 0 
7fdc03afa000-7fdc03bfa000 rw-p 00000000 00:00 0 
7fdc03bfa000-7fdc03bfb000 ---p 00000000 00:00 0 
7fdc03bfb000-7fdc03cfb000 rw-p 00000000 00:00 0 
7fdc03cfb000-7fdc03cfc000 ---p 00000000 00:00 0 
7fdc03cfc000-7fdc03dfc000 rw-p 00000000 00:00 0 
7fdc03dfc000-7fdc03dfd000 ---p 00000000 00:00 0 
7fdc03dfd000-7fdc03efd000 rw-p 00000000 00:00 0 
7fdc03efd000-7fdc03efe000 ---p 00000000 00:00 0 
7fdc03efe000-7fdc03ffe000 rw-p 00000000 00:00 0 
7fdc03ffe000-7fdc03fff000 ---p 00000000 00:00 0 
7fdc03fff000-7fdc040ff000 rw-p 00000000 00:00 0 
7fdc040ff000-7fdc04100000 ---p 00000000 00:00 0 
7fdc04100000-7fdc04200000 rw-p 00000000 00:00 0 
7fdc04200000-7fdc04201000 ---p 00000000 00:00 0 
7fdc04201000-7fdc04301000 rw-p 00000000 00:00 0 
7fdc04301000-7fdc04302000 ---p 00000000 00:00 0 
7fdc04302000-7fdc04402000 rw-p 00000000 00:00 0 
7fdc04402000-7fdc04403000 ---p 00000000 00:00 0 
7fdc04403000-7fdc04503000 rw-p 00000000 00:00 0 
7fdc04503000-7fdc04504000 ---p 00000000 00:00 0 
7fdc04504000-7fdc04604000 rw-p 00000000 00:00 0 
7fdc04604000-7fdc04605000 ---p 00000000 00:00 0 
7fdc04605000-7fdc04705000 rw-p 00000000 00:00 0 
7fdc04705000-7fdc04706000 ---p 00000000 00:00 0 
7fdc04706000-7fdc04806000 rw-p 00000000 00:00 0 
7fdc04806000-7fdc04807000 ---p 00000000 00:00 0 
7fdc04807000-7fdc04907000 rw-p 00000000 00:00 0 
7fdc04907000-7fdc04908000 ---p 00000000 00:00 0 
7fdc04908000-7fdc04a08000 rw-p 00000000 00:00 0 
7fdc04a08000-7fdc04a09000 ---p 00000000 00:00 0 
7fdc04a09000-7fdc04b09000 rw-p 00000000 00:00 0 
7fdc04b09000-7fdc04b0a000 ---p 00000000 00:00 0 
7fdc04b0a000-7fdc04c0a000 rw-p 00000000 00:00 0 
7fdc04c0a000-7fdc04c0b000 ---p 00000000 00:00 0 
7fdc04c0b000-7fdc04d0b000 rw-p 00000000 00:00 0 
7fdc04d0b000-7fdc04d0c000 ---p 00000000 00:00 0 
7fdc04d0c000-7fdc04e0c000 rw-p 00000000 00:00 0 
7fdc04e0c000-7fdc04e0d000 ---p 00000000 00:00 0 
7fdc04e0d000-7fdc04f0d000 rw-p 00000000 00:00 0 
7fdc04f0d000-7fdc04f0e000 ---p 00000000 00:00 0 
7fdc04f0e000-7fdc0500e000 rw-p 00000000 00:00 0 
7fdc0500e000-7fdc0500f000 ---p 00000000 00:00 0 
7fdc0500f000-7fdc0510f000 rw-p 00000000 00:00 0 
7fdc0510f000-7fdc05110000 ---p 00000000 00:00 0 
7fdc05110000-7fdc05210000 rw-p 00000000 00:00 0 
7fdc05210000-7fdc05211000 ---p 00000000 00:00 0 
7fdc05211000-7fdc05311000 rw-p 00000000 00:00 0 
7fdc05311000-7fdc05312000 ---p 00000000 00:00 0 
7fdc05312000-7fdc05412000 rw-p 00000000 00:00 0 
7fdc05412000-7fdc05413000 ---p 00000000 00:00 0 
7fdc05413000-7fdc05513000 rw-p 00000000 00:00 0 
7fdc05513000-7fdc05514000 ---p 00000000 00:00 0 
7fdc05514000-7fdc05614000 rw-p 00000000 00:00 0 
7fdc05614000-7fdc05615000 ---p 00000000 00:00 0 
7fdc05615000-7fdc05715000 rw-p 00000000 00:00 0 
7fdc05715000-7fdc05716000 ---p 00000000 00:00 0 
7fdc05716000-7fdc05816000 rw-p 00000000 00:00 0 
7fdc05816000-7fdc05817000 ---p 00000000 00:00 0 
7fdc05817000-7fdc05917000 rw-p 00000000 00:00 0 
7fdc05917000-7fdc05918000 ---p 00000000 00:00 0 
7fdc05918000-7fdc05a18000 rw-p 00000000 00:00 0 
7fdc05a18000-7fdc05a19000 ---p 00000000 00:00 0 
7fdc05a19000-7fdc05b19000 rw-p 00000000 00:00 0 
7fdc05b19000-7fdc05b1a000 ---p 00000000 00:00 0 
7fdc05b1a000-7fdc05c1d000 rw-p 00000000 00:00 0 
7fdc05c1d000-7fdc083ff000 rw-p 00000000 00:00 0 
7fdc083ff000-7fdc0840a000 rw-p 00000000 00:00 0 
7fdc0840a000-7fdc08428000 rw-p 00000000 00:00 0 
7fdc08428000-7fdc0842b000 rw-p 00000000 00:00 0 
7fdc0842b000-7fdc0ac0c000 rw-p 00000000 00:00 0 
7fdc0ac0c000-7fdc0ac0f000 rw-p 00000000 00:00 0 
7fdc0ac0f000-7fdc0bfff000 rw-p 00000000 00:00 0 
7fdc0bfff000-7fdc0c000000 rw-p 00000000 00:00 0 
7fdc0c000000-7fdc0c077000 rw-p 00000000 00:00 0 
7fdc0c077000-7fdc10000000 ---p 00000000 00:00 0 
7fdc1005b000-7fdc1005c000 ---p 00000000 00:00 0 
7fdc1005c000-7fdc1015c000 rw-p 00000000 00:00 0 
7fdc1015c000-7fdc1015d000 ---p 00000000 00:00 0 
7fdc1015d000-7fdc1025d000 rw-p 00000000 00:00 0 
7fdc1025d000-7fdc1025e000 ---p 00000000 00:00 0 
7fdc1025e000-7fdc1035e000 rw-p 00000000 00:00 0 
7fdc1035e000-7fdc1035f000 ---p 00000000 00:00 0 
7fdc1035f000-7fdc1045f000 rw-p 00000000 00:00 0 
7fdc1045f000-7fdc10460000 ---p 00000000 00:00 0 
7fdc10460000-7fdc1056b000 rw-p 00000000 00:00 0 
7fdc1056b000-7fdc10589000 rw-p 00000000 00:00 0 
7fdc10589000-7fdc10593000 rw-p 00000000 00:00 0 
7fdc10593000-7fdc10649000 rw-p 00000000 00:00 0 
7fdc10649000-7fdc108b9000 rwxp 00000000 00:00 0 
7fdc108b9000-7fdc13649000 rw-p 00000000 00:00 0 
7fdc13649000-7fdc13663000 r-xp 00000000 08:02 9308536                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libzip.so
7fdc13663000-7fdc13863000 ---p 0001a000 08:02 9308536                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libzip.so
7fdc13863000-7fdc13864000 rw-p 0001a000 08:02 9308536                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libzip.so
7fdc13864000-7fdc13870000 r-xp 00000000 08:02 3932190                    /lib64/libnss_files-2.12.so
7fdc13870000-7fdc13a70000 ---p 0000c000 08:02 3932190                    /lib64/libnss_files-2.12.so
7fdc13a70000-7fdc13a71000 r--p 0000c000 08:02 3932190                    /lib64/libnss_files-2.12.so
7fdc13a71000-7fdc13a72000 rw-p 0000d000 08:02 3932190                    /lib64/libnss_files-2.12.so
7fdc13a72000-7fdc13a7a000 rw-s 00000000 08:02 2097165                    /tmp/hsperfdata_bdcsc2/25470
7fdc13a7a000-7fdc13aa3000 r-xp 00000000 08:02 9308541                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libjava.so
7fdc13aa3000-7fdc13ca3000 ---p 00029000 08:02 9308541                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libjava.so
7fdc13ca3000-7fdc13ca5000 rw-p 00029000 08:02 9308541                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libjava.so
7fdc13ca5000-7fdc13cb2000 r-xp 00000000 08:02 9308528                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libverify.so
7fdc13cb2000-7fdc13eb1000 ---p 0000d000 08:02 9308528                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libverify.so
7fdc13eb1000-7fdc13eb3000 rw-p 0000c000 08:02 9308528                    /usr/local/jdk1.7.0_76/jre/lib/amd64/libverify.so
7fdc13eb3000-7fdc13eb6000 ---p 00000000 00:00 0 
7fdc13eb6000-7fdc13fb4000 rw-p 00000000 00:00 0 
7fdc13fb4000-7fdc14b29000 r-xp 00000000 08:02 9308514                    /usr/local/jdk1.7.0_76/jre/lib/amd64/server/libjvm.so
7fdc14b29000-7fdc14d29000 ---p 00b75000 08:02 9308514                    /usr/local/jdk1.7.0_76/jre/lib/amd64/server/libjvm.so
7fdc14d29000-7fdc14ded000 rw-p 00b75000 08:02 9308514                    /usr/local/jdk1.7.0_76/jre/lib/amd64/server/libjvm.so
7fdc14ded000-7fdc14e31000 rw-p 00000000 00:00 0 
7fdc14e31000-7fdc14e47000 r-xp 00000000 08:02 9962479                    /usr/local/jdk1.7.0_76/lib/amd64/jli/libjli.so
7fdc14e47000-7fdc15047000 ---p 00016000 08:02 9962479                    /usr/local/jdk1.7.0_76/lib/amd64/jli/libjli.so
7fdc15047000-7fdc15048000 rw-p 00016000 08:02 9962479                    /usr/local/jdk1.7.0_76/lib/amd64/jli/libjli.so
7fdc15048000-7fdc15049000 rw-p 00000000 00:00 0 
7fdc1504d000-7fdc15050000 rw-p 00000000 00:00 0 
7fdc15050000-7fdc15051000 r--p 00000000 00:00 0 
7fdc15051000-7fdc15052000 rw-p 00000000 00:00 0 
7fff8fa5b000-7fff8fa70000 rw-p 00000000 00:00 0                          [stack]
7fff8fb79000-7fff8fb7a000 r-xp 00000000 00:00 0                          [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]
 
VM Arguments:
jvm_args: -Dapplication.home=/usr/local/jdk1.7.0_76 -Xms8m 
java_command: sun.tools.jstat.Jstat -gcutil 24156 1000 10
Launcher Type: SUN_STANDARD
 
Environment Variables:
JAVA_HOME=/usr/local/jdk1.7.0_76/
PATH=/data/flumecollector/hbase/hbase-0.98.8-hadoop2/bin:/data/flumecollector/hive/apache-hive-0.14.0-bin/bin:/data/flumecollector/hive/apache-hive-0.14.0-bin/hcatalog/
bin:/data/flumecollector/hive/apache-hive-0.14.0-bin/hcatalog/sbin:/data/flumecollector/hadoop/hadoop-2.6.0/bin:/data/flumecollector/hadoop/hadoop-2.6.0/sbin:/usr/local
/jdk1.7.0_76//bin:/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/bdcsc2/bin/bin
SHELL=/bin/bash
 
Signal Handlers:
SIGSEGV: [libjvm.so+0x9a3bd0], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGBUS: [libjvm.so+0x9a3bd0], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGFPE: [libjvm.so+0x81cb60], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGPIPE: [libjvm.so+0x81cb60], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGXFSZ: [libjvm.so+0x81cb60], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGILL: [libjvm.so+0x81cb60], sa_mask[0]=0x7ffbfeff, sa_flags=0x10000004
SIGUSR1: SIG_DFL, sa_mask[0]=0x00000000, sa_flags=0x00000000
SIGUSR2: [libjvm.so+0x81e360], sa_mask[0]=0x00000000, sa_flags=0x10000004
SIGHUP: SIG_DFL, sa_mask[0]=0x00000000, sa_flags=0x00000000
SIGINT: SIG_DFL, sa_mask[0]=0x00000000, sa_flags=0x00000000
SIGTERM: SIG_DFL, sa_mask[0]=0x00000000, sa_flags=0x00000000
SIGQUIT: SIG_DFL, sa_mask[0]=0x00000000, sa_flags=0x00000000
 
 
---------------  S Y S T E M  ---------------

View Code

详细文档：

学习ulimit命令的用法。
功能说明：控制shell程序的资源。
语　　法：ulimit [-aHS][-c <core文件上限>][-d <数据节区大小>][-f <文件大小>][-m <内存大小>][-n <文件数目>][-p <缓冲区大小>][-s <堆叠大小>][-t <CPU时间>][-u <程序数目>][-v <虚拟内存大小>]
补充说明：ulimit为shell内建指令，可用来控制shell执行程序的资源。
参　　数：

复制代码

代码如下:

-a 　显示目前资源限制的设定。
-c <core文件上限> 　设定core文件的最大值，单位为区块。
-d <数据节区大小> 　程序数据节区的最大值，单位为KB。
-f <文件大小> 　shell所能建立的最大文件，单位为区块。
-H 　设定资源的硬性限制，也就是管理员所设下的限制。
-m <内存大小> 　指定可使用内存的上限，单位为KB。
-n <文件数目> 　指定同一时间最多可开启的文件数。
-p <缓冲区大小> 　指定管道缓冲区的大小，单位512字节。
-s <堆叠大小> 　指定堆叠的上限，单位为KB。
-S 　设定资源的弹性限制。
-t <CPU时间> 　指定CPU使用时间的上限，单位为秒。
-u <程序数目> 　用户最多可开启的程序数目。
-v <虚拟内存大小> 　指定可使用的虚拟内存上限，单位为KB。

ulimit -a 用来显示当前的各种用户进程限制。
Linux对于每个用户，系统限制其最大进程数。为提高性能，可以根据设备资源情况，设置各linux 用户的最大进程数。
例如，把某linux用户的最大进程数设为10000个：
ulimit -u 10000
对于需要做许多 socket 连接并使它们处于打开状态的 Java 应用程序而言，
最好通过使用 ulimit -n xx 修改每个进程可打开的文件数，缺省值是 1024。
ulimit -n 4096 将每个进程可以打开的文件数目加大到4096，缺省为1024
其他建议设置成无限制（unlimited）的一些重要设置是：

复制代码

代码如下:

数据段长度：ulimit -d unlimited
最大内存大小：ulimit -m unlimited
堆栈大小：ulimit -s unlimited
CPU 时间：ulimit -t unlimited
虚拟内存：ulimit -v unlimited

有时服务器需要调整ulimit的stack size 参数调整为unlimited 无限，使用ulimit -s unlimited时只能在当时的shell见效，重开一个shell则失效。

解决方法：

在/etc/profile 的最后面添加ulimit -s unlimited。
然后：
# source /etc/profile
使修改即时生效。
可能的问题：
如果碰到类似的错误提示
ulimit: max user processes: cannot modify limit: 不允许的操作
ulimit: open files: cannot modify limit: 不允许的操作
以上操作对root用户是不会提示这样的限制信息的，只对普通用户有影响，原因何在？
大家可以去研究下文件：/etc/security/limits.conf。
说明：
linux对用户有默认的ulimit限制，而这个文件可以配置用户的硬配置和软配置，硬配置是个上限。
超出上限的修改就会出“不允许的操作”这样的错误。
可以在limits.conf文件最后添加相关内容，如下图：

即限制任意用户的最大线程数和文件数为10240。