Skip to main content

Saturday morning live: SLES9+DRBD upgrade

I have not worked on saturday mornings (at least officially) since 2001, but today I planned an upgrade of a SLES 9 cluster to the latest patchlevel. The cluster uses drbd to replicate two disks, used mainly for samba sharing.

My plan was to try a rolling upgrade, even tough nobody is at work today, so that I could get some experience on this and avoid other saturday mornings live ;-) . From what I understand drbd can be upgraded on one node at the time as the protocol is compatible between minor versions and since the upgrade was from 0.7.pre to 0.7.5 I thought: ok, I can do it.
Believe it or not it is not true: the pre thing in the original SLES9 is not compatibile with the one that comes from online update. So I had to upgrade both and then reboot. The whole process took about one hour (add some time for safety checks on partitions, etc) and I was really disappointed that even in the suse support portal this was not mentioned at all!
Except for that drbd did not force a full resync (as it would have done in the 0.6.x versions) and the cluster came up very quickly.

Have a nice weekend!

Comments

Popular posts from this blog

Indexing Apache access logs with ELK (Elasticsearch+Logstash+Kibana)

Who said that grepping Apache logs has to be boring?

The truth is that, as Enteprise applications move to the browser too, Apache access logs are a gold mine, it does not matter what your role is: developer, support or sysadmin. If you are not mining them you are most likely missing out a ton of information and, probably, making the wrong decisions.
ELK (Elasticsearch, Logstash, Kibana) is a terrific, Open Source stack for visually analyzing Apache (or nginx) logs (but also any other timestamped data).

From 0 to ZFS replication in 5m with syncoid

The ZFS filesystem has many features that once you try them you can never go back. One of the lesser known is probably the support for replicating a zfs filesystem by sending the changes over the network with zfs send/receive.
Technically the filesystem changes don't even need to be sent over a network: you could as well dump them on a removable disk, then receive  from the same removable disk.

Detect missed executions with OpenNMS

Everyone knows that OpenNMS is a powerful monitoring solution, but not everyone knows that since version 1.10 circa it embeds the Drools rule processing engine. Drools programs can then be used to extend the event handling logic in new and powerful ways.

The following example shows how OpenNMS can be extended to detect missed executions for recurring activities like backups or scheduled jobs.