By using the Pacemaker 1.1.15 release, the LINBIT cluster stack has been cutting-edge. Now the distributions are catching up. Continue reading
TL;DR: Pairing DRBD with VDO reduces the replication network and storage utilization by ~85% while increasing load by ~0.8.
VDO (Virtual Data Optimizer) is a ready-to-run software package that delivers block-level deduplication, compression, and thin provisioning capabilities to Linux. VDO operates inline at a 4 KB granularity, delivering the best possible balance of performance and data reduction rates.
We have been testing out some 240GB Micron M500DC SSDs with DRBD 9 and DRBD’s RDMA Transport layer. Micron, based in Boise Idaho, is a leader in NAND, flash production and storage. We found that that their M500DC SSD’s are write optimized for data center use cases and in some cases exceeded the expected performance.
Nowadays, Docker has support for plugins; for LINBIT, volume plugins are certainly the most interesting feature. Volume plugins open the way for storing content residing in usual Docker volumes on DRBD backed storage.
In this blog post we show a simple example of using our new Docker volume plugin to create a WordPress powered blog with a MariaDB database, where both the content of the blog and the database is replicated among two cluster nodes. Continue reading
As you might know, DRBD Manage is a tool that is used in the DRBD9 stack to manage (create, remove, snapshot) DRBD resources in a multi-node DRBD cluster. DRBD Manage stores the cluster information in the so called Control Volume. The control volume is a DRBD9 resource itself which is then replicated across the whole cluster. This means that the control volume itself is just a block device, like all the regular DRBD resources. Continue reading
SanDisk Corporation designs, develops and manufactures flash memory storage solutions. LINBIT is known for developing DRBD (Distributed Replicated Block Device), the backbone of Linux High Availability software. LINBIT tested how quickly data can be synchronously replicated from a SanDisk 800 GB SSD in server A, to an identical SSD located in server B. Disaster Recovery replication was also investigated, using the same hardware to an off-site server.
Over the next few weeks we’ll be posting results from tests that we’ve run against various manufactures SSD drives; including Intel, SanDisk, and Micron, to name a few.
The first post in this series goes over our findings of the Intel DC S 3700 Series 800GB SATA SSD drives. Continue reading
DRBD9 has a new transport abstraction layer and it is designed for speed; apart from
TCP the next generation link will be
So, what is RDMA, and how is it different from TCP? Continue reading