Starting Rescue Mode in Ubuntu 11.10

It’s a little difficult to find the rescue mode in Ubuntu 11.10. Since 11.04 you can press the shift key in startup phase to show up the grub boot menu. First step is changing the following line in /etc/default/grub GRUB_HIDDEN_TIMEOUT=0 to GRUB_HIDDEN_TIMEOUT=1 Activate the changes by running /usr/sbin/upgrade-grub. Now you can boot up your system and can press the shift key to access the grub menu. Another important thing is that the file systems are mounted read-only in rescue mode. If you want make changes to the file systems then you must first choose the remount option in the boot[…]

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Postfix setup for SSL and TLS

To use SSL and TLS with the postfix mailer daemon you must change settings in the /etc/postfix/main.cf configuration file: # tls config smtp_use_tls = yes smtpd_use_tls = yes smtp_tls_note_starttls_offer = yes smtpd_tls_CAfile = /etc/postfix/ssl/demoCA/cacert.pem smtpd_tls_cert_file = /etc/postfix/ssl/server-crt.pem smtpd_tls_key_file = /etc/postfix/ssl/server-key.pem smtpd_tls_loglevel = 1 smtpd_tls_received_header = yes smtpd_tls_session_cache_timeout = 3600s tls_random_source = dev:/dev/urandom tls_random_prng_update_period = 3600s You also need a SSL certificate for your mail server. Create it with the following commands: mkdir /etc/postfix/ssl cd /etc/postfix/ssl/ # Create new local certification authority (if not already present) /usr/share/ssl/misc/CA.pl -newca # Create RSA certificate openssl req -new -nodes -keyout server-key.pem -out server-req.pem -days[…]

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IMAP server setup under SuSE Linux

First you must install the UW-Imap daemon with yast. UW-Imap uses the standard mail folder structure from Linux, so no additional configuration is needed. Create SSL certificates The certificates are stored in folder /etc/ssl/certs. Change to this directory: cd /etc/ssl/certs Now create the certificates for your system with the following command: openssl req -new -x509 -nodes -out imapd.pem -keyout imapd.pem -days 365 You are asked about country name (2 letter code), state or province Name (full name), locality name (eg, city), organization name (eg, company), organizational unit name (eg, section), common name (eg, your name) and email address. For ¬ęcommon[…]

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Make bootable USB stick for Linux installation

You need a Linux installation image, e.g. SUSE-Linux-10.1-Remastered-i386-mini.iso. You can download this from a openSuSE mirror server. The package syslinux must be installed to make a bootable USB stick. So if you haven’t it installed you must do so now. Asume your USB stick is accessed with device name /dev/sda1, you can use the following commands to write the image to the stick and make it bootable: umount /dev/sda1 mount -o loop SUSE-Linux-10.1-Remastered-i386-mini.iso /mnt /mnt/boot/i386/mkbootdisk –32 –partition /dev/sda1 /mnt

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