error 1. postdrop: warning: unable to look up public/pickup: No such file or directory mkfifo /var/spool/postfix/public/pickup systemctl restart postfix 2. postmap: fatal: bad string length 0

# postfix 재시작 postfix reload # hash 파일 등록 postmap /etc/postfix/${filename} # postfix 설정 확인 postconf -n # 메일 큐 전체 비우기 postfix flush or postfix -f # 메일 큐 확인 mailq # 메일큐 전체 삭제 postsuper -d ALL # 메일큐 중 deferred 상태만 삭제 postsuper -d ALL deferred

환경 : Ubuntu 20.04 패키지 : postfix, sasl # postfix install apt-get install postfix /etc/postfix/main.cf # See /usr/share/postfix/main.cf.dist for a commented, more complete version # Debian specific: Specifying a file name will cause the first # line of that file to be used as the name. The Debian default # is /etc/mailname. #myorigin = /etc/mailname smtpd_banner = $myhostname ESMTP $mail_name (Ubu..

문제 E: could not get lock /var/lib/dpkg/lock-frontend. It is held by process (unattended-upgr) N: Be aware that removing the lock file is not a solution and may break your system. E: Unable to acquire the dpkg frontend lock (/var/lib/dpgk/lock-frontend), is a nother process using it? 해결방법 killall apt apt-get rm /var/lib/apt/lists/lock rm /var/cache/apt/archives/lock rm /var/lib/dpkg/lock* dpkg --..

# error unable to resolve host ${hostname}: Name or service not known solution vi /etc/hosts 127.0.0.1 ${hostname} #hostname add

root@test1:~# passwd root New password: Retype new password: Sorry, passwords do not match. passwd: Authentication token manipulation error passwd: password unchanged root@test:~# passwd root New password: Retype new password: Sorry, passwords do not match. passwd: Module is unknown passwd: password unchanged solution chmod 0640 /etc/shadow mount -o remount,rw /

[junhee.lee:root@root ~]# cat /etc/fstab # # /etc/fstab # Created by anaconda on Mon Apr 16 08:39:40 2018 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # LABEL=ROOT / ext4 noatime,nodiratime 1 1 LABEL=CDNET /usr/local/cdnet ext4 noatime,nodiratime 1 2 LABEL=SWAP swap swap defaults 0 0 tmpfs /..

[root@centos7 ~]# systemctl start firewalld Failed to start firewalld.service: Unit is masked. Failed to start firewalld.service: Unit is masked. 출력시 systemctl unmask firewalld [root@centos7 ~]# systemctl unmask firewalld Removed symlink /etc/systemd/system/firewalld.service. [root@centos7 html]# systemctl status firewalld ● firewalld.service - firewalld - dynamic firewall daemon Loaded: loaded ..

[junhee.lee:root@host ~]# cat /var/log/messages | egrep -i '(error|fail)' Jan 6 04:55:49 host kernel: [Hardware Error]: Machine check events logged Jan 6 05:31:21 host kernel: [Hardware Error]: Machine check events logged Jan 6 06:03:25 host kernel: [Hardware Error]: Machine check events logged Jan 6 06:36:04 host kernel: [Hardware Error]: Machine check events logged Jan 6 07:09:19 host kernel: ..

" Syntax Highlighting if has("syntax") syntax on endif set nu "line set fileencodings=utf8,euc-kr "encodeing set hlsearch "hilight search "set autoindent 들여쓰기 "set cindent set ts=4 set sts=4 set shiftwidth=4 set laststatus=2 set showmatch set smartcase set smarttab "set smartindent set ruler

[junhee.lee:root@* /]# ls -al ls: cannot access test [junhee.lee:root@* /test]# ls ls: cannot open directory .: Input/output error 1. / 디렉토리에서 ls 명령어를 입력하게되면 cannot access test 문구가 출력된다. 2. /test 디렉토리에서 ls 명령어를 입력하게되면 ls: cannot open directory .: Input/output error 문구가 출력된다. - 단순 디스크 문제인줄 알았지만 마운트 설정이 잘못되어있어서 발생하는 오류였다. 3. 디스크 장애가 발생했을때 생기는 오류 - 디스크 교체 필요하다. 자료 손실될 가능성도 생각해야한다. 4. 디스크 용량이 가득 찼을때..

업데이트 및 패키지 설치 yum -y update sudo -y yum install yum-utils sudo -y yum groupinstall development IUM 저장소 설치 # CentOS 6 yum install \ https://repo.ius.io/ius-release-el6.rpm \ https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm # CentOS 7 yum install \ https://repo.ius.io/ius-release-el7.rpm \ https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm Python 설치 # 라이브러..