DRBD Proxy 3.1: Performance improvements

The threading model in DRBD Proxy 3.1 received a complete overhaul; below you can see the performance implications of these changes. Read more

“umount is too slow”

A question we see over and over again is

Why is umount so slow? Why does it take so long?

Part of the answer was already given in an earlier blog post; here’s some more explanation. Read more

Change the cluster distribution without downtime

Recently we’ve upgraded one of our virtualization clusters (more RAM), and in the course of this did an upgrade of the virtualization hosts from Ubuntu Lucid to RHEL 6.3 — without any service interruption. Read more

Mirrored SAN vs. DRBD

Every now and then we get asked “why not simply use a mirrored SAN instead of DRBD”? This post shows some important differences. Read more

Best Practice: Use Backup with your DRBD cluster!

We want to take an opportunity to explain LINBIT’s best practices in regards to DRBD and backup procedures.

Read more

“read-balancing” with 8.4.1+

DRBD 8.4.1 introduces a new feature: read-balancing, which is configured in the disk section of the configuration file(s). This feature enables DRBD to balance read requests between the Primary/Secondary nodes. Read more

LINBIT participates in the German Cloud (“Deutsche Wolke”)

 

Deutsche Wolke (“German Cloud”) was founded to establish Federal Cloud Infrastructure in Germany.

This infrastructure will provide additional legal and security protections for hosted data.  No longer will small businesses be exposed to the legal risk of losing their website presence without a trial (an unfortunate reality when doing business on transatlantic clouds).

The natural partner for backend storage infrastructure is LINBIT; as authors and maintainers of DRBD, we are best suited to provide the technical expertise to achieve High Availability.  Also, LINBIT DR is the obvious choice for off-site or disaster recovery replication (from the office into the cloud).

We at LINBIT look forward to seeing this project grow and prosper!

Monitoring: better safe than sorry…

Stumbling upon the Holy time-travellin’ DRBD, batman! blog post there’s only one thing to be said …

Be strict in what you emit, liberal in what you accept[1. Thanks, Larry]

is simply not true when dealing with mission-critical systems.

It’s ok to be alerted on upgrading a machine because the “old, working” RegEx that did the parsing doesn’t match anymore[1. eg. because /proc/drbd got an additional field]; it’s not a problem to get an email when someone adds the 100th DRBD resource and causes the grep to fail; and so on. Read more

Maximum volume size on DRBD

From time to time we get asked things like this:

I want to use a 100TiB volume with DRBD, is that supported”?

The biggest public device size with DRBD known to LINBIT is currently ~600TiB. (JUNE 2019 UPDATE) Read more