What is DRBD? DRBD is a distributed replicated storage system for the Linux platform. It is implemented as a kernel driver, several user-space management applications, and some shell scripts. DRBD is traditionally used in high availability (HA) computer clusters, but beginning with DRBD version 9, it can also be used to create larger software defined storage pools with…
Read MoreA common issue in cluster environment is the split brain condition. A split brain occurs when some nodes of the cluster are not able to communicate properly, but instead continue to work like two separate, distinct clusters leading to data or service inconsistency. To prevent this situation a common solution is to introduce the concept…
Read MoreAs soon as you manage more than a few DRBD resources distributed over a wide set of hardware, split brain situations cannot always be avoided. Standard split brains are caused by multiple nodes having different opinions about the latest state of the data on their local disk. Disclaimer: If applied incorrectly, commands in this blog…
Read MoreHistorically, NetEye Clusters were configured with DRBD as Master/Slave resources. This led to the following rather cumbersome resource configuration for an N-node cluster: $SERVICE_drbd_master ( x 1 ) $SERVICE_drbd_master_clone ( x N ) $SERVICE_drbd_fs $SERVICE_virt_ip $SERVICE Note: $SERVICE serves as a placeholder for any Cluster Service running in NetEye 4. At least ten constraints were…
Read MoreDuring the Nagios World Conference Europe™, one of the topic that will be presented is “Real Time Cluster Synchronisation for more Reliability in High Availability Systems”. Martin Loschwitz, Linbit Senior consultant, will clarify this concept introducing new Linux standards DRBD and explaining how DRBD can substitute the SAN data center. “The data are the lifeblood…
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