Posted on 2019/04/23 18:19
Filed Under Linux/설정방법

DNS server, DNS service  

Overview

In most Linux Distributions core file creation is disabled by default for a normal user. However, it can be necessary to enable this feature for an application (e.g. Oracle). For example, if you encounter an ORA-7445 error in Oracle, then it must be possible to write a core file for the user«oracle».

To enable writing core files you use the ulimit command, it controls the resources available to a process started by the shell, on systems that allow such control.

If you try to enable writing core files, usually you run in the following problem. Normally SSH is used to logon to the server.

ssh oracle@ora-server
$ ulimit -a

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
file size               (blocks, -f) unlimited
pending signals                 (-i) 1024
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 65536
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 16384
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

Nowtry (not as user root) to change the core file size to unlimited

ulimit -c unlimited
-bash: ulimit: core file size: cannot modify limit: Operation not permitted

Solution

  1. Check Environment for ulimit

    The first step is to check, that you don't set ulimit -c 0 in any shell configuration files for this user, for example in $HOME/.bash_profile or $HOME/.bashrc. Uncomment it if you have such an entry.

    #
    # Do not produce core dumps
    #
    # ulimit -c 0
     
  2. Globally enable Core Dumps

    This must be done as user root, usually in /etc/security/limits.conf

    # /etc/security/limits.conf
    #
    #
     Each line describes a limit for a user in the form:
    #
    #
     <domain> <type> <item> <value>
    #

    *  soft  core  unlimited

     
  3. Logoff and Logon again and set ulimit

    ssh oracle@ora-server
    $ ulimit -c
    0

    Try to set the limit as user root first

    su -
    ulimit -c unlimited

    ulimit -c
    unlimited

    Now you can set ulimit also for user oracle

    su - oracle
    ulimit -c unlimited
    ulimit -c
    unlimited

Perhaps the last step number 3 is not necessary, but we have figured out, that this is the way which always work. The core file size limitation is usually also set in different configuration files. If you want to enable cores, you can uncomment them.

In /etc/profile (Redhat)

# No core files by default
# ulimit -S -c 0 > /dev/null 2>&1

In /etc/init.d/functions (Redhat)

# make sure it doesn't core dump anywhere unless requested
# ulimit -S -c ${DAEMON_COREFILE_LIMIT:-0} >/dev/null 2>&1

Now, from this current shell you can generate the core, so check ulimit before.

$ ulimit -a

core file size          (blocks, -c) unlimited
data seg size           (kbytes, -d) unlimited
file size               (blocks, -f) unlimited
pending signals                 (-i) 1024
max locked memory       (kbytes, -l) 32
max memory size         (kbytes, -m) unlimited
open files                      (-n) 65536
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 16384
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

2019/04/23 18:19 2019/04/23 18:19

트랙백 주소 : 이 글에는 트랙백을 보낼 수 없습니다

Posted on 2019/03/29 15:08
Filed Under Programming/Tools

DNS server, DNS service  

svn 은 하나의 repository 만 설정할 수 있지만,
git 은 여러개의 repository 를 설정할 수 있다.

more..

 

remote 가 http/https 일경우 다음과 같이 설정하면 된다.

 

more..


인증이 필요할 경우 매번 id 와 암호를 입력해야 하므로 id 정도는 url 에 같이 포함시키는 것이 편리하다. id와 @ 를 도메인 앞에 붙여 주면 된다.

 

more..

 

새로 추가된 remote에 기존의 내용(commit)을 업데이트 (push)하기 위해서는 다음의 명령어도 가능

 

more..


모든 remote 에서 branch 및 update 된 내역을 가져오려면 다음 명령어 실행(HEAD 에 merge 하지는 않는다.)

 

more..


alt remote 의 master branch 에서 fetch 하고 현재 HEAD 에 pull

 

more..

 

매번 repository 마다 push/pull 을 따로 해줘야 하는게 번거롭다면 stackoverflow의 pull/push from multiple remote locations 글의 http://stackoverflow.com/a/3195446 답변을 참고

 

2019/03/29 15:08 2019/03/29 15:08

트랙백 주소 : 이 글에는 트랙백을 보낼 수 없습니다

Posted on 2019/02/19 17:34
Filed Under Windows/장애처리

DNS server, DNS service  

FTDI 드라이버 고급속성 (장치관리자에서 COM 포트 속석)에서 "Serial Enumerator (직렬 니유머레이터" 항목을 비활성화

원인 : https://stackoverrun.com/ko/q/2408753
자세한 내용 : http://www.ftdichip.com/Support/Documents/AppNotes/AN_107_AdvancedDriverOptions_AN_000073.pdf
2019/02/19 17:34 2019/02/19 17:34

트랙백 주소 : 이 글에는 트랙백을 보낼 수 없습니다

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