a simple line to add to /etc/pam.d/system-auth to show failed login attempts like this There were 166327 failed login attempts since the last successful login. simple run the following sed -i –follow-symlinks ‘/pam_limits.so/a sessiont requiredt pam_lastlog.so showfailed’ /etc/pam.d/system-auth
I decided that I need a DLNA server on my network so that I can stream to my tablets/phones/smartTV’s with ease. I already have media PC’s at every TV however I wanted to test out the smart TV features on my TV. Unfortunately there are no known pre-builds of any light weight DLNA servers for CentOS7. I selected miniDLNA which is now called ReadyMedia. miniDLNA is a light weight DLNA compliant server and best of all it comes pre-compiled as a static binary which does not need anything else to run. Current version of miniDLNA at the time of writing… Continue Reading
A bit tired of too many ad’s poping up on various sites especially those links from facebook etc.. so I’ve combined multiple sources to block ad’s using my dd-wrt router. Place the following into Administration->Commands and save as startup rm /tmp/hosts mkdir /tmp/abc wget -qO /tmp/abc/addhosts http://szojox.ugu.pl/hosts wget -qO /tmp/abc/jansal http://jansal.googlecode.com/svn/trunk/adblock/hosts wget -qO /tmp/abc/malwaredomain http://www.malwaredomainlist.com/hostslist/hosts.txt wget -qO /tmp/abc/winhelp2002 http://winhelp2002.mvps.org/hosts.txt wget -qO /tmp/abc/adaway https://adaway.org/hosts.txt wget -qO /tmp/abc/ad_servers http://hosts-file.net/.%5Cad_servers.txt wget -qO /tmp/abc/gjtech http://adblock.gjtech.net/?format=unix-hosts wget -qO /tmp/abc/someone http://someonewhocares.org/hosts/hosts cat /tmp/abc/addhosts /tmp/abc/jansal /tmp/abc/malwaredomain/tmp/abc/winhelp2002 /tmp/abc/adaway /tmp/abc/ad_servers /tmp/abc/gjtech /tmp/abc/someone | sed -e ‘s/^[ t]*//’ | grep -v ^# | sort | uniq > /tmp/hosts rm -rf… Continue Reading
systemd is the new init system, started with Fedora and now started adopted in many distributions like redhat, suse and centos. This long period we all been using traditional SysV init scripts usually residing in /etc/rc.d/init.d/ directory. These scripts invokes daemon binary which will then forks a background process. Even though shell scripts very are flexible buts other tasks like supervising processes and parallized execution ordering will be very hard to implement. With the introduction of systemd new-style daemons which makes easier to supervise and control them at runtime and simplifies their implementation. systemctl command is a very good initiative… Continue Reading
sometimes you have multiple qcow2 files sitting around from older upgrades and OS’s that you just need to grab a file or a config from and dont want to bother with booting it up. there is a way to mount the filesystem using libguestfs which can save time! This works with LVM and non LVM qcow2 files and also even if you dont know how the qcow2 partitions are laid out you can feed it a bogus partition and it will list it for you. # guestmount -a rhel5.qcow2 -m /dev/sdzz1 /mnt libguestfs: error: mount_options: mount_options_stub: /dev/sdzz1: No such file… Continue Reading
Due to the complex and sensitive environments of today world many groups of servers will require to get quarterly or annual security audits especially if they are part of PCI. Unfortunately for Sysadmin’s most security scanning tools are blind to backports done by both redhat and novell. backporting is where the security patches are applied to the older (current) versions of the packages that was shipped with a particular version of the operating system. So while you can have 1 major version of the package installed it will have many different versions of backports applied to it. The process itself… Continue Reading
Many times when downloading via command line large files you might want to run it in the background and forget about it. you can run this is screen however its also good to use wget options. one quicky is to do wget -bqc url -b is to background as soon as starting -c is to resume broken downloads -q is to quiet wget
Once in a while you will want to setup clusters with shared disks to test and play around with various clusters. while this is easy to do in kvm/xen/etc its not so easy with virtualbox. There is a way via command line tools to create disks and attaching it so that it is shared. For me I have windows 7 64bit and I am running virtualbox 64bit 4.xxxxx. It is most likely easier if you include the path for “c:Program FilesOracleVirtualBox” however if you do not its ok. We will need to run the command VBoxManage or “c:Program FilesOracleVirtualBoxVBoxManage.exe” if… Continue Reading
There is a built in tool to remove old unused kernels thats installed onto the system. You can just as easily remove it and clean grub entries but this is an automated method and you can even set an option to keep x amounts. step 1 – install the yum utils package yum install yum-utils step 2 – run the package-cleanup to clean up old kernels package-cleanup –oldkernels –count=2 step 3 – if you want to set it so that you only keep X number of revisions on your system then edit /etc/yum.conf and add the following installonly_limit=2 enjoy!
I wanted to setup a PDC via samba for my home network since I am wanting a common login onto all of the machines at home and also since I already share files via samba why not just add this. This is a very novice basic setup of PDC. Several items are needed espcially host entries/dns records to make this work. lets assume several items Domain : testdomain.local PDC Hostname : pdc PDC IP : 192.168.1.1 User : thisisyou Client Hostname : testdesktop 1. Install Samba. yum groupinstall “CIFS file server” or yum install samba 2. Network testing from your… Continue Reading