From 5a81402497580d378efc149deccfb62b17e1c0f5 Mon Sep 17 00:00:00 2001 From: Andreas Dilger Date: Wed, 25 Jul 2018 15:10:49 -0600 Subject: [PATCH] LUDOC-11 config: Improve writeconf description Improve the description of the "tunefs.lustre --writeconf" command. Signed-off-by: Andreas Dilger Change-Id: I96df1d566b83b118ef58ea17cffd1b6fad12fc24 Reviewed-on: https://review.whamcloud.com/32886 Reviewed-by: Joseph Gmitter Tested-by: Jenkins --- LustreMaintenance.xml | 102 ++++++++++++++++++++++++++------------------------ 1 file changed, 54 insertions(+), 48 deletions(-) diff --git a/LustreMaintenance.xml b/LustreMaintenance.xml index 10b618c..4082661 100644 --- a/LustreMaintenance.xml +++ b/LustreMaintenance.xml @@ -117,10 +117,12 @@ Mounting a Server Without Lustre Service
<indexterm><primary>maintenance</primary><secondary>regenerating config logs</secondary></indexterm> Regenerating Lustre Configuration Logs - If the Lustre file system configuration logs are in a state where the file system cannot - be started, use the writeconf command to erase them. After the - writeconf command is run and the servers restart, the configuration logs - are re-generated and stored on the MGS (as in a new file system). + If the Lustre file system configuration logs are in a state where + the file system cannot be started, use the + tunefs.lustre --writeconf command to regenerate them. + After the writeconf command is run and the servers + restart, the configuration logs are re-generated and stored on the MGS + (as with a new file system). You should only use the writeconf command if: @@ -130,82 +132,84 @@ Regenerating Lustre Configuration Logs A server NID is being changed - The writeconf command is destructive to some configuration items (i.e., OST pools information and items set via conf_param), and should be used with caution. To avoid problems: - - - Shut down the file system before running the writeconf command - - - Run the writeconf command on all servers (MDT first, then OSTs) - - - Start the file system in this order: - - - MGS (or the combined MGS/MDT) - - - MDT - - - OSTs - - - Lustre clients - - - - + The writeconf command is destructive to some + configuration items (e.g. OST pools information and tunables set via + conf_param), and should be used with caution. - The OST pools feature enables a group of OSTs to be named for file striping purposes. If you use OST pools, be aware that running the writeconf command erases all pools information (as well as any other parameters set via lctl conf_param). We recommend that the pools definitions (and conf_param settings) be executed via a script, so they can be reproduced easily after a writeconf is performed. + The OST pools feature enables a group of OSTs to be named for + file striping purposes. If you use OST pools, be aware that running + the writeconf command erases + all pools information (as well as + any other parameters set via lctl conf_param). + We recommend that the pools definitions (and + conf_param settings) be executed via a script, + so they can be regenerated easily after writeconf + is performed. However, tunables saved with lctl set_param + -P are not erased in this case. + + If the MGS still holds any configuration logs, it may be + possible to dump these logs to save any parameters stored with + lctl conf_param by dumping the config logs on + the MGS and saving the output: + +mgs# lctl --device MGS llog_print fsname-client +mgs# lctl --device MGS llog_print fsname-MDT0000 +mgs# lctl --device MGS llog_print fsname-OST0000 + + To regenerate Lustre file system configuration logs: - Shut down the file system in this order. + Stop the file system services in the following order before + running the tunefs.lustre --writeconf command: + Unmount the clients. - Unmount the MDT. + Unmount the MDT(s). - Unmount all OSTs. + Unmount the OST(s). + + + If the MGS is separate from the MDT it can remain mounted + during this process. - Make sure the the MDT and OST devices are available. + Make sure the MDT and OST devices are available. - Run the writeconf command on all servers. - Run writeconf on the MDT first, and then the OSTs. + Run the tunefs.lustre --writeconf command + on all target devices. + Run writeconf on the MDT(s) first, and then the OST(s). - On the MDT, run: - mdt# tunefs.lustre --writeconf /dev/mdt_device + On each MDS, for each MDT run: + mds# tunefs.lustre --writeconf /dev/mdt_device - - On each OST, run: - - ost# tunefs.lustre --writeconf /dev/ost_device + On each OSS, for each OST run: + oss# tunefs.lustre --writeconf /dev/ost_device - Restart the file system in this order. + Restart the file system in the following order: - Mount the MGS (or the combined MGS/MDT). + Mount the separate MGT, if it is not already mounted. - Mount the MDT. + Mount the MDT(s) in order, starting with MDT0000. - Mount the OSTs. + Mount the OSTs in order, starting with OST0000. Mount the clients. @@ -213,7 +217,9 @@ Regenerating Lustre Configuration Logs - After the writeconf command is run, the configuration logs are re-generated as servers restart. + After the tunefs.lustre --writeconf command is + run, the configuration logs are re-generated as servers connect to the + MGS.
<indexterm><primary>maintenance</primary><secondary>changing a NID</secondary></indexterm> -- 1.8.3.1