In high-performance enterprise environments, the chain is only as strong as its weakest link. I recently faced a critical issue where a long-running task in my development machine running in JBoss Application Server was failing consistently. The investigation led me down a path from application timeouts deep into the core I/O mechanics of the Oracle… Read More »
We all know back-up is important and a must have in case of critical systems. Making a backup on tape is one of the best industry standards that is still unmatched. In the following I am presenting a simple way to make tape back-ups using tar and LTFS on LTO5 and up tapes. Why LTFS… Read More »
Following is a simple and easy way to do a consistent back-up of the /home directory (usually mounted in a separate partition) on a running system. We do not have the luxury of being able to stop the operations of a server and unmount the home partition to make sure no changes are done during… Read More »
At some point an increase in size of the replicated resource is needed. This can be caused by an increase in data retention times or an increase of transaction numbers affecting that resource. If the backing block devices can be grown while in operation (online), it is also possible to increase the size of a… Read More »
Even when you think that you know something well enough you discover that there are some corner cases you never encountered. This is the main reason I like IT system administration tasks, you never get bored. This post is about one of this corner cases in a DRBD setup described in post #DRBD based disk… Read More »
In a DRBD setup as described in #DRBD based disk replication of a production cluster to a remote site cluster on RHEL 6 there is a special case when due to some external issues the communication line between the sites is down due to technical reason for a longer period of time (days). The line… Read More »
This is another post related to the DRBD replication setup I describe in post #DRBD based disk replication of a production cluster to a remote site cluster on RHEL 6. Sometimes we need to be able to mount the offline replicated Oracle database instance for investigations. This can be done by using logical volume snapshots.… Read More »
Finally a new release of the HPE MicroServer updated at the new generation Gen10. HPE ProLiant MicroServer Gen10 It seems that the Gen8 release of the MicroServer was so successful (I am the proud owner of 3 HP MicroServer Gen8) that HPE never released a Gen9 model. What are the main updates after a quick… Read More »
I have a RHEL 6 Linux cluster setup where the main database storage is replicated on a remote site using DRBD. In case of a failure of the primary site the decision is taken to move operations on the remote site. When the production site is back online sometimes the administrator is too eager to… Read More »
There is an interesting case of failing technology due to an unimplemented feature. See the following mail list thread for the original post. Basically if you deploy DRBD and one of the endpoints is a vmware virtual machine: – when trying to mount a newly created etx4 file-system over the LVM from the drbd device… Read More »