From 6b283f6ea1f1750eb77bd4955303af47e9f4092b Mon Sep 17 00:00:00 2001 From: Jonathan Boulle Date: Fri, 7 Nov 2014 16:34:19 -0800 Subject: [PATCH] docs: reword failure descriptions --- Documentation/0.5/admin_guide.md | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Documentation/0.5/admin_guide.md b/Documentation/0.5/admin_guide.md index b19b89f13..ec204cdac 100644 --- a/Documentation/0.5/admin_guide.md +++ b/Documentation/0.5/admin_guide.md @@ -32,9 +32,11 @@ The data directory has two sub-directories in it: If you are spinning up multiple clusters for testing it is recommended that you specify a unique initial-cluster-token for the different clusters. This can protect you from cluster corruption in case of mis-configuration because two members started with different cluster tokens will refuse members from each other. -### Disaster recovery +### Disaster Recovery -In some circumstances, it may be necessary to recover an etcd cluster from a critical failure where quorum has been irrevocably lost. For example, if a three-node cluster suffered two simultaneous machine failures, it would be normally impossible for the cluster to restore quorum and continue functioning. To recover from such scenarios, etcd provides functionality to backup and restore the datastore and recreate the cluster without data loss. +etcd is designed to be resilient to machine failures. An etcd cluster can automatically recover from any number of temporary failures (for example, machine reboots), and a cluster of N members can tolerate up to _(N/2)-1_ permanent failures (where a member can no longer access the cluster, due to hardware failure or disk corruption). However, in extreme circumstances, a cluster might permanently lose enough members such that quorum is irrevocably lost. For example, if a three-node cluster suffered two simultaneous and unrecoverable machine failures, it would be normally impossible for the cluster to restore quorum and continue functioning. + +To recover from such scenarios, etcd provides functionality to backup and restore the datastore and recreate the cluster without data loss. #### Backing up the datastore