centos

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mysql changing to utf8 and converting DB to utf8

Posted on by jlim0930

by default mysql is installed as latin1 and sometimes it causes problems when your data is not always latin1. Follow the steps to change mysql to utf and also convert existing databases to UTF8 #1 backup your databases and convert it to UTF8 mysqldump -uusername -ppassword -c -e –default-character-set=utf8 –single-transaction –skip-set-charset –add-drop-database -B dbname -r dbname.utf8.dump.sql do this for each of your databases. #2 shutdown mysql service mysqld stop #3 edit /etc/my.cnf ADD to [mysqld] section # init_connect=’SET collation_connection = utf8_unicode_ci’ init_connect=’SET NAMES utf8′ character-set-server=utf8 collation-server=utf8_unicode_ci skip-character-set-client-handshake also [client] default-character-set=utf8 #4 restart mysqld service mysqld start #5 import your databases… Continue Reading →

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VirtualBox – how to create and share disks to setup/test clusters

Posted on by jlim0930

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 →

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cleaning old kernels the easy way

Posted on by jlim0930

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!

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is it safe to use epel and rpmforge at the same time ?

Posted on by jlim0930

There are many repositories that you can add onto your RHEL/CENTOS/FEDORA OS to install additional software. full list of repos can be found here http://wiki.centos.org/AdditionalResources/Repositories however is it safe to just add the repos and start installing packages? yes and no. We will configure priorities to setup the repos to keep packages from conflicting. Also you will want to protect the base OS installation so that there is less corruption/conflicts later on. step 1 – install the plugin if its not installed already yum install -y yum-plugin-priorities yum-plugin-protectbase step 2 – setup priorities for *-Base.repo that came with your OS… Continue Reading →

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Samba as a Primary Domain Controller on Centos/RHEL

Posted on by jlim0930

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 →

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How to rollback YUM UPDATES

Posted on by jlim0930

Once in a while you might have problems after running “yum update.” There is an intermediate solution by rollback feature included in YUM. THIS OPTION IS NOT ENABLED BY DEFAULT. 1. To enable rollback edit /etc/yum.conf and add tsflags=repackage 2. Add the following line into /etc/rpm/macros file if it doesn’t exist and add %_repackage_all_erasures 1 now you are all set and can use the following examples to rollback rpm -Uvh –rollback ’22:00′ rpm -Uvh –rollback ‘3 hours ago’ rpm -Uvh –rollback ‘june 13’ rpm -Uvh –rollback ‘yesterday’ All previous repackaged software will be stored onto /var/spool/repackage

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Inspiron 530 Linux Experience

Posted on by jlim0930

So recently I purchaed a Dell Inspiron 530 with Core 2 Quad CPU.  According to Dell this computer can only take up to 4GB of memory but it always has the intel G33 chipset and according to intel it should be able to do up to 8GB of memory. From looking at the motherboard it looks like its a OEMed Foxconn G33M motherboard but of course Dell put their own bios and did not solder in 2 of the sata connectors.  If you go into the BIOS you can see 6 SATA connectors but on the physical board itself it… Continue Reading →