Cheap Votes: DRBD Diskless Quorum

One of the most important considerations when implementing clustered systems is ensuring that a cluster remains cohesive and stable given unexpected conditions. DRBD already has fencing mechanisms and even a system of quorum, which is now capable of using a diskless arbitrator to break ties without requiring additional storage beyond that of two nodes. Quorum […]

DRBD and the sync-rate controller, part 3

This is an update to our previous two blog posts here and here. The goal with this post is to even further simplify the steps needed to tune the sync-rate controller. If you compare this post against the previous two post, you’ll see that I omit a few options, and even just simply pick some […]

How LINBIT Improved the DRBD Sync-Rate Logic

About nine years ago, LINBIT introduced the dynamic sync-rate controller in DRBD 8.3.9. The goal behind this was to tune the amount of resync traffic so as to not interfere or compete with application IO to the DRBD device. We did this by examining the current state of the resync, application IO, and network, ten […]

NVMe-oF and iSCSI (iSER)

As a Linux storage company, LINBIT is always excited for an opportunity to work with the latest developments in storage. One of these new technologies is NVMe over fabrics (NVMe-oF). NVMe is a device specification for nonvolatile memory that utilizes the PCIe bus. NVMe-oF allows us to use these specifications over a network. You can […]

Highly available LINSTOR Controller with Pacemaker

Part of the design of LINSTOR is that if the central LINSTOR Controller goes down, all the storage still remains up and accessible. This should allow ample time to repair the downed system hosting the LINSTOR Controller. Still, in the majority of cases, it is preferred to run the LINSTOR Controller in a container within […]

DRBD and Randtronics DPM

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Today we’re happy to announce a new document titled “Block Replication with Filesystem Encryption” which showcases another wonderful use case for DRBD. Block Replication with Filesystem Encryption At Hosting Con, back in April of this year, some colleagues of mine ran into some representatives from Randtronics. Randtronics is the company responsible for the DPM (Data […]

Oracle DynDNS with Booth Geo-Clustering

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Pacemaker was never designed to operate across the WAN, or any high latency networks. However, there has always been a need and desire to orchestrate active/passive failovers between data centers and across long distances. To address this issue the Booth Pacemaker add-on was conceived back in late 2011. LINBIT has been involved in the development […]

DRBD Client (diskless mode) Performance

DRBD 9 introduces an interesting new feature; DRBD client nodes. With this feature you can have a DRBD node which has no local replica itself. Essentially, the client node simply reads and writes to the storage of the peer systems using the DRBD connections. As DRBD’s communication is designed to operate with minimal overhead I […]

Diskless vs iSCSI

With DRBD 9 we introduced the concept of a client, or diskless, node. This node has no local storage itself, and simply reads and writes to the DRBD peers which do have storage via the native DRBD transports. This is a useful feature and is often used to connect nova-compute nodes to cinder storage nodes […]