Author Archives: George Valentin Voina

RedHat/Fedora Linux NIC bonding

By | February 9, 2017

Red Hat Enterprise Linux allows administrators to bind multiple network interfaces together into a single channel using the bonding kernel module and a special network interface called a channel bonding interface. Channel bonding enables two or more network interfaces to act as one, simultaneously increasing the bandwidth and providing redundancy. The behaviour of the bonded… Read More: RedHat/Fedora Linux NIC bonding »

Oracle: Get the real size of a table with blobs

By | February 8, 2017

As we now in case of a table with BLOBs in the actual table row only a reference to the BLOB is stored. In order to get the real table size of my table ‘MY_BLOB_TABLE’ including the refereed BLOBs the following query holds in Oracle: SELECT sum( bytes)/1024/1024 size_in_MB FROM user_segments WHERE (segment_name = ‘MY_BLOB_TABLE’… Read More: Oracle: Get the real size of a table with blobs »

Oracle: Resolve blocking processes

By | February 8, 2017

Sometimes an oracle query goes nuts and blocks the DB. To find the blocked processes started by user MYUSER execute: SELECT s.inst_id, s.sid, s.serial#, p.spid, s.username, s.program FROM gv$session s JOIN gv$process p ON p.addr = s.paddr AND p.inst_id = s.inst_id where s.username like ‘MYUSER’; To kill the blocking process: ALTER SYSTEM KILL SESSION ‘sid,serial#’

HP Microserver Gen8 compatibility list

By | January 28, 2021

As a big fan of the HP Microserver Gen8 (I own 3 of them in two locations) I compiled my own list of compatible hardware that I am using or used in building the servers.I have to thank the good fan forums that I always consult previous of buying new hardware for my HP Microservers… Read More: HP Microserver Gen8 compatibility list »

DB2: (SQL Error: -30090) caused by XA access to a nickname to a federated database

By | February 8, 2017

In a setup having an enterprise application depending on a database instance where some tables are defined as nicknames to tables from a federated database, it can happen to get this very cryptic DB2 error. [12/10/15 18:06:54:895 IST] 00000073 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions SQL Error: -4229, SQLState: null [12/10/15 18:06:54:903 IST] 00000073 SqlExceptionH Z org.hibernate.engine.jdbc.spi.SqlExceptionHelper… Read More: DB2: (SQL Error: -30090) caused by XA access to a… »

#DRBD based disk replication of a production cluster to a remote site cluster on RHEL 6

By | May 26, 2017

1 General Considerations Our example enterprise applications run on a Linux Cluster with a shared cluster storage resource. Having this HA setup ensures that we have a high rate of service availability on the production site. To ensure that the disruption time in service of our enterprise application is minimal as possible the best solution… Read More: #DRBD based disk replication of a production cluster to a… »