From bc2b8856d7ed6971c1b15328a7e8484ac8bdef4b Mon Sep 17 00:00:00 2001 From: Raoof Mohammed Date: Tue, 25 Aug 2015 12:30:56 -0400 Subject: [PATCH] doc: correct calculation of fault tolerance of an etcd cluster in admin_guide.md doc: correct calculation of fault tolerance of an etcd cluster in admin_guide.md --- Documentation/admin_guide.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/admin_guide.md b/Documentation/admin_guide.md index 0b4a7e4ee..3a172ea14 100644 --- a/Documentation/admin_guide.md +++ b/Documentation/admin_guide.md @@ -137,7 +137,7 @@ etcd -name infra1 \ ### Disaster Recovery -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. +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-1)/2_ 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.