Cynic's Blog

BACK UP EVERYTHING BEFORE TRYING THIS. The entire process can be split into 4 stages. 1. Physically increasing the vdi file size on the host machine. This requires help from the hypervisor OEM. For VDI, which is a native VirtualBox image, we'll use VBoxManage. VBoxmanage modifyhd centos.vdi --resize 100000 If the above command doesn't work and throw an error about this feature not being implemented, you might try the following instead. Create a new disk with higher capacity VBoxManage clonemedium --existing 2. Resize the LVM. For this we'll use GParted to resize the image. Boot up a GParted live CD and resize the required LVM partition to suit your need. 3. Resize the LVM-2 Boot up the machine with the newly extended image and check df -h and fdisk -l. You'll see that the disk has indeed grown, but LVM hasn't. Use the following command to resize LVM to full size. pvresize /dev/sda2 (assuming your LVM partition is sda...

Symmetric DS is an awesome tool for trigger based replication whcih works for all major database vendors, including but not limited to PostgreSQL, MySQL, MSSQL, Oracle and many others. Symmetric-DS is a java application and can execute on any platform on whcih JRE is available including Windows and Linux. Trigger based replication, in constrast to disk based (eg. DRBD ) or transaction log file shipping based or statement based , works by registering triggers on DMLs and sending the data thus generated to remote machines. Another very popular trigger based DB replication tool is Slony . Symmetric-DS in addition to being database agnostic also supports multi-master replication (MMR). MMR usecase involves multiple database nodes, connected in a pool with DML updates coming from any of them. This is different from the normal master-slave replication, where slaves are not expected to generate any data events, and the sole authority of database is the master. MMR requirement causes d...