Talk:Two Node Fedora 13 Cluster - Xen-Based Virtual Machine Host on DRBD+CLVM: Difference between revisions
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--[[User:SRSullivan|SRSullivan]] 20:05, 15 October 2010 (UTC) | --[[User:SRSullivan|SRSullivan]] 20:05, 15 October 2010 (UTC) | ||
== Tracking when to restart cman after reboots == | |||
During the creation of devices we reboot the machine, previous instructions had us turn of cman from starting on boot. For the final release document we should carefully note when cman will be down and when it should be re-enabled either manually or permanently. | |||
--[[User:SRSullivan|SRSullivan]] 17:44, 18 October 2010 (UTC) | |||
Revision as of 17:44, 18 October 2010
We'll remove the yum -y before the document goes live. For now, I want it there to save time while (repeatedly) rebuilding the clusters as it saves a lot of time.
--Digimer 18:58, 13 October 2010 (UTC)
Dealing with Raid 5/6
Under raid 5/6 if you follow these instruction to closely you'll end up with bad config data in mdadm.conf
cat /proc/mdstat
Personalities : [raid1] [raid6] [raid5] [raid4]
md3 : active raid5 sdd5[4] sdc5[2] sdb5[1] sda5[0]
1395170304 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/3] [UUU_]
[=====>...............] recovery = 26.5% (123522028/465056768) finish=126.7min speed=44896K/sec
md2 : active raid5 sda1[0] sdd1[4] sdc1[2] sdb1[1]
62909952 blocks super 1.1 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md1 : active raid5 sda2[0] sdd2[4] sdc2[2] sdb2[1]
6286848 blocks super 1.1 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
md0 : active raid1 sda3[0] sdd3[3] sdc3[2] sdb3[1]
255988 blocks super 1.0 [4/4] [UUUU]
unused devices: <none>
You will notice the [UUU_]. The default, and this is not in the documentation for mdadm, is to build the array with a degraded spare and then resync it. This is faster, but produces false data for the next step if it is done before the array completes it resync.
Ref: [1]
mdadm --detail --scan | grep md3 >> /etc/mdadm.conf
cat /etc/mdadm.conf
Will produce:
ARRAY /dev/md3 metadata=1.2 spares=1 name=localhost.localdomain:3 UUID=b4fc7771:bef0b6a5:c4c40550:ab3bff42
Which should actually be the following (with out the spares=1)
ARRAY /dev/md3 metadata=1.2 name=localhost.localdomain:3 UUID=b4fc7771:bef0b6a5:c4c40550:ab3bff42
--SRSullivan 20:05, 15 October 2010 (UTC)
Tracking when to restart cman after reboots
During the creation of devices we reboot the machine, previous instructions had us turn of cman from starting on boot. For the final release document we should carefully note when cman will be down and when it should be re-enabled either manually or permanently. --SRSullivan 17:44, 18 October 2010 (UTC)