https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LU-16722 Lustre <p>Restructure the MGS config management system to better handle modern environments.</p> <p>Allowing multiple redundant MGS/MGT devices in a filesystem (e.g. one replica running on each of 4 separate MDS nodes) would significantly improve reliability, since clients could still mount in the face of an MGS failure, and imperative recovery would continue to work.</p> LU-16722

MGS config log restructuring and redundancy

Improvement Minor Open Unresolved Andreas Dilger Colin Faber Fri, 7 Apr 2023 17:39:09 +0000 Sat, 9 Dec 2023 20:31:14 +0000 0 5 <p>As yet, no investigation has been done in this area. Open questions for discussion and resoultion include:</p> <ul class="alternate" type="square"> <li>do clients only connect to a single MGS, but perform some kind of round-robin selection of the target NID to use at mount, to distribute load among the MGS instances?</li> <li>how are config logs replicated between MGT instances? <ul> <li>Using FLR layouts for the files on the MGT would re-use existing infrastructure, and give a clear indication of which is the primary mirror and which mirrors might be "stale" and need to be resync'd from the primary. On the flip side, this might complicate the replication.</li> <li>Using a llog consumer on the backup MGTs to read the config logs and store locally (as the MDT and OST llog copies are handled) would give more independence between the MGTs</li> </ul> </li> <li>are the "backup" MGTs read-only, or could one of them take over in case the primary MGT fails?  Or should there be a manual resync process from any of the backup MGTs if the primary is corrupted?  There are not very many files on the MGT, so doing a full reformat/resync is relatively simple.</li> </ul> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>     14  100644 (1)      0      0   12288 25-Nov-2023 00:50 mountdata      82  100644 (1)      0      0    8192 31-Dec-1969 17:00 nodemap      85  100644 (1)      0      0   11032 31-Dec-1969 17:00 params      86  100644 (1)      0      0   22808 31-Dec-1969 17:00 testfs-client      87  100644 (1)      0      0   28552 31-Dec-1969 17:00 testfs-MDT0000     154  100644 (1)      0      0   28016 31-Dec-1969 17:00 testfs-MDT0001     156  100644 (1)      0      0   27480 31-Dec-1969 17:00 testfs-MDT0002     158  100644 (1)      0      0   26944 31-Dec-1969 17:00 testfs-MDT0003     160  100644 (1)      0      0   17992 31-Dec-1969 17:00 testfs-OST0000     166  100644 (1)      0      0   17680 31-Dec-1969 17:00 testfs-OST0001     167  100644 (1)      0      0   17144 31-Dec-1969 17:00 testfs-OST0002     168  100644 (1)      0      0   16608 31-Dec-1969 17:00 testfs-OST0003 </pre> </div></div> Related LU-10360 LU-13308 LU-13306 LU-16738 Development Rank 1|i03if3: Rank (Obsolete) 9223372036854775807