From 2a940e3619b0ae37b3a98b1bd6f297ac54a29879 Mon Sep 17 00:00:00 2001 From: Neil Brown Date: Mon, 7 Aug 2006 11:11:42 +1000 Subject: Document usage of version0.91 superblock. --- md.4 | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'md.4') diff --git a/md.4 b/md.4 index d22ded4..cd00065 100644 --- a/md.4 +++ b/md.4 @@ -74,6 +74,14 @@ UUID a 128 bit Universally Unique Identifier that identifies the array that this device is part of. +When a version 0.90 array is being reshaped (e.g. adding extra devices +to a RAID5), the version number is temporarily set to 0.91. This +ensures that if the reshape process is stopped in the middle (e.g. by +a system crash) and the machine boots into an older kernel that does +not support reshaping, then the array will not be assembled (which +would cause data corruption) but will be left untouched until a kernel +that can complete the reshape processes is used. + .SS ARRAYS WITHOUT SUPERBLOCKS While it is usually best to create arrays with superblocks so that they can be assembled reliably, there are some circumstances where an -- cgit