General

• The Postfix Homepage (Latest: 3.1.2 as of 2016-10-02)
• Will Will Web: 如何刪除 Postfix 中所有還沒發送的郵件
  postsuper -d ALL or postsuper -d ALL deferred

• Networkinghowto: Limit Postfix to listen on specific IP addresses

  edit: /etc/postfix/main.cf
  change: inet_interfaces = all
  restart postfix service
  

• EasyEngine: Postfix, Dovecot, ViMbAdmin, RoundCube (Looks more complete)
  SELinux can affect the auto-create maildir for Dovecot, must disable it first
  This config works for authentication (AUTH PLAIN LOGIN)

• Ubuntu 12.04 – Install Postfix, Dovecot and Vimbadmin (Complete postfix config for mysql)
• Email with Postfix, Dovecot, and MySQL
• step by step guide to installing ViMbAdmin from various sources
• Vimbadmin Mail System Install on Ubuntu

NFS & Firewall ports

• Fixing Ports Used by NFSv3 Server

  Uncomment or add these lines to /etc/sysconfig/nfs:
  RQUOTAD_PORT=875
  LOCKD_TCPPORT=32803
  LOCKD_UDPPORT=32769
  MOUNTD_PORT=892
  STATD_PORT=662
  
  After restarting nfs and rpcbind,
  check by: rpcinfo -p
  

• CentOS forum: Bug – Locking down nfs – port settings ignored?
• Bug 450208 – NFS doesn’t stop rpc.rquotad

  All I had to do was uncomment the following line in /etc/sysconfig/nfs:
  RQUOTAD="/usr/sbin/rpc.rquotad"
  
  The problem stems from the fact that $RQUOTAD is initialized in the start
  portion of /etc/init.d/nfs but not the stop portion.
  

• 鳥哥的 Linux 私房菜 – 第十三章、檔案伺服器之一：NFS 伺服器

NFS configuration

• Kerberos authentication with NFSv4
• How to configure nfsv4 with kerberos in RHEL?

• 17 Command Line Tools to Monitor Linux Performance

ntpd

• ‘ntpq -p’ meanings

NTP issues

• ntp.org: Known Hardware Issues
  APIC, ACPI, Variable Speed Processors could cause problems to NTP
• ntp.org: NTP Known Operating System Issues
• ntp.org: Troubleshooting NTP
• ntpd (4.2.2p1) stays “synchronized to LOCAL" – NTP
• Novell: Time Not Syncing With Remote NTP Server
• NTP Debugging Techniques
• Fix NTP problem by reduce kernel HZ value (unconfirmed)
• General NTP HOWTO
• 鳥哥的 Linux 私房菜: NTP server
• Bug 165826 – NTP cannot keep clock in sync on HP DL385-type systems
• Tuning NTP
  This guy said to use HPET timer
• VMware: Timekeeping best practices for Linux guests

Fedora Linux

• Bug 702261 – network service not running on minimal install (Fedora 15, 16 also)
  Fedora 15: service network start, edit: ONBOOT="yes" to ifcfg-eth0

• A more human readable Linux kernel changes

Administration

• systemctl in Fedora 15+
  • systemctl list-unit-files
  • systemctl enable xxxxx.service
  • systemctl disable xxxxx.service
  • How to start qmail / netqmail using systemd
• Resolve RedHat Enterprise Linux 6.0 / CentOS 6.0 default no network problem (edit ifcfg-eth0 file)
• Common RPM commands list

  rpm -qa --qf '%{SIZE} %{NAME}\n' | sort -nr | nl | head -10 # 10 largest RPMs

• CentOS 4.4 minimal services mini HOWTO
• Red Hat Magazine – Understanding your (Red Hat Enterprise Linux) daemons
• Easy Automated Snapshot-Style Backups with Linux and Rsync
  Include a very good rsync commandline example
• Command to check no. of forward connections per ip. To find out peer-to-peer clients

  cat /proc/net/ip_conntrack | cut -d ' ' -f 10 | cut -d '=' -f 2 | sort | uniq -c | \
  sort -nr | head -n 5

• HOWTO: Root filesystem over LVM2, DM-Crypt and RAID
• unable to use eth0 after cloned a system
  Related to: /lib/dev/70-persistent-net-rules of the udev package. Remove generated file /etc/udev/rules.d/70-persistent-net.rules to fix the problem. Alternative can remove this rule file to allow more flexible change of ethX devices. This problem could arise in FC10.
  • Related Fedora mailing list article

Clonezilla Live

• Command line to restore individual partition:
  gunzip -c VolGroupHPSTD-root.ext3-ptcl-img.gz.aa | partclone.ext3 -r -d -s – -o /dev/sda2

sendmail

• ERROR: did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA after turned on authentication

Apache HTTPD

• Mod_Rewrite and Regular Expressions Apache Web Server forum at WebmasterWorld
• Apache 2.0 URL Rewriting Guide

SSH

• Key-Based SSH Logins With PuTTY – Page 2
• Build-in has support for sftp operation

Perl

• CPAN.pm needs either the external programs tar, gzip and bzip2 installed. Can’t continue.
  Fix by run ‘cpan’ or ‘sudo perl -MCPAN -eshell’, then send these commands in CPAN shell:

  o conf tar /bin/tar
  o conf bzip2 /bin/bzip2
  o conf gzip /bin/gzip
  o conf commit

ASSP

• Anti-Spam SMTP Proxy Server (1.5.1.4 2009-07-01)
• ASSP 1.x Forum
• assp-user mailing list searchable archive
• Starting from 1.5.1.1, can use other virus scanner other than ClamAV
• 1.x is single threaded only, 2.x is multi-threaded (not released yet)
• E-mail Interface
  • assp-white@domain.com
  • assp-notwhite@domain.com
  • assp-spam@domain.com
  • assp-notspam@domain.com
• Methods to whitelist a single address in ASSP
• ASSP Deluxe – cPanel based ASSP solution
• Mailing List thread on whitelist interface

PPPoE Server

• If not specified IP address at /etc/pap-secrets, then client cannot connect?
• General PPP options

WiFi

• Linux Wireless Support page
  List all the Linux supported Wireless adapter by chipset and vendor/model (USB / PCI or CardBus or PCI-E / PCMCIA)

LVM

• HOWTO: Back Up (And Restore) LVM Partitions With LVM Snapshots
• LVM on Software RAID

iptables

• use iptables as a simple tcp proxy

  iptables -A PREROUTING -p tcp --dport 80 -d old.ip.add.ress -j DNAT --to new.ip.add.ress
  iptables -A FORWARD -p tcp --dport 80 -d new.ip.add.ress -j ACCEPT
  iptables -A POSTROUTING -p tcp --dport 80 -d new.ip.add.ress -j SNAT --to my.ip.add.ress

• PacketProxy
  A simple TCP proxy
• tcpproxy
  A more full feature TCP proxy, can handle multiple connections

LDAP Server

• Quick Steps to setup OpenLDAP in FC3

IMAP Server

• Dovecot
• Dovecot logging documentation

Rescue CDs

General requirements for a Linux rescue CD:
- Best with at least 2.6.18 kernel, support later SATA controllers
(e.g. JMICRON 36x only in 2.6.18)
- AHCI support
- Network support with newer network drivers
- Can load the whole CD into RAM
- Can install to USB key
- Optional upgradable kernel

• System Rescue CD
  Latest version 0.3.0 at 2006-12-20, size: 150M
  Kernel 2.6.18.5 patched, can load the whole CD into RAM (‘docache’ boot option), can install to USB key
  To boot system into RAM, require 320M RAM! (nofb docache noxdetect)
• R.I.P. Linux
  Latest version 1.9 at 2006-06-23, size: 35M (without X), 75M (with X)
  Kernel 2.6.17 patched, can load the whole CD into RAM, can install to USB key (will erase the whole USB key!)
  To boot system into RAM, only require 96M RAM
  Replace to a newer kernel is easy, just use the website’s kernel config and minor adjust with the new kernel (mainly on RAID456 and SATA drivers), and don’t patch the kernel with the tmpfs patch, then it will work.

Troubleshooting

• hub connect-debounce failed error at CentOS 5
  No solution, temporary fix is to run: modprobe -r ehci-hcd
  Workaround is to disable USB Legacy Support in BIOS (tried not ok)

PKI

• EJBCA – The J2EE CA (3.5.4, 2008-01-29)
  Java, Web-based CA
• OpenCA PKI (0.9.3-rc1, 2006-10-10)
• PHPki Digital Certificate Authority (0.82, 2007-07-22, stalled)