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-10995 Lustre <p>We don't yet support all-MDT systems, but I'm sure it is only a matter of time until we do. I think the main limitation is that we don't allow clients to use the filesystem until the MDS has connected to at least one OST, to prevent clients just getting errors when trying to use the filesystem (before DoM). </p> <p>We probably also need some testing to ensure we allow DoM file creates without OST components even if no OSTs are connected. We might also need to lift the 1GB dom_stripesize limit in that case.</p> <p>Finally, we might need to handle MDT and OST on the same node better during recovery, but it might also just work since the MDT always uses the same connection UUID.</p> LU-10995

DoM2: allow MDT-only filesystems

Improvement Minor Open Unresolved WC Triage Andreas Dilger DoM2 Thu, 3 May 2018 16:33:35 +0000 Sun, 16 Jan 2022 08:24:57 +0000 0 8 <p>Copied from <a href="https://jira.whamcloud.com/browse/LU-11471" title="IO Errors during failover with very few number of OSTs" class="issue-link" data-issue-key="LU-11471"><del>LU-11471</del></a> to have all related notes in one ticket:</p> <blockquote> <p>With the advent of Data-on-MDT we will at some point want to allow filesystems with only MDTs to be created. At that point, this check has to be removed.</p> <p>As a starting point, we could add a tunable that allows this behavior to be selected by the admin - return an error if no OSTs are available, or cause the client to block and wait for an OST to become available. I think in the case where an OST was previously available, but they are temporarily offline due to failover, the client should block. If the file being created has a DoM component at the start, then it should not block.</p></blockquote> Related LU-10176 LU-11471 LU-11023 LU-11421 LU-11425 Development Rank 1|hzzwrb: Rank (Obsolete) 9223372036854775807