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-9362 Lustre <p>Recent testing on master with files with multiple components show that several tests fail due to ‘lfs getstripe’ with the index or the stripe count flags return multiple lines of output. If this impacts the Lustre test suites, this could impact exiting tools that use ‘lfs getstripe’ and expect output of a single value. </p> <p>To demonstrate this, we have a file with three components:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>[root@eagle-48vm6 ]# lfs getstripe /lustre/scratch/d9.sanity/d2/d3 /lustre/scratch/d9.sanity/d2/d3 lcm_layout_gen: 0 lcm_entry_count: 3 lcme_id: N/A lcme_flags: 0 lcme_extent.e_start: 0 lcme_extent.e_end: 2097152 stripe_count: 1 stripe_size: 1048576 stripe_offset: -1 lcme_id: N/A lcme_flags: 0 lcme_extent.e_start: 2097152 lcme_extent.e_end: 16777216 stripe_count: 2 stripe_size: 2097152 stripe_offset: -1 lcme_id: N/A lcme_flags: 0 lcme_extent.e_start: 16777216 lcme_extent.e_end: EOF stripe_count: 4 stripe_size: 4194304 stripe_offset: -1 [root@eagle-48vm6 ]# lfs getstripe -i /lustre/scratch/d9.sanity/d2/d3 -1 -1 -1 [root@eagle-48vm6 ]# lfs getstripe -c /lustre/scratch/d9.sanity/d2/d3 1 2 4 </pre> </div></div> <p>Andreas Dilger has commented on this issue:</p> <blockquote> <p>"lfs getstripe -c" should return a single value for the stripe count. In the design, this was the stripe count of the last instantiated component, since that is the best estimate for the number of stripes for the given file. In the implementation (AFAIK) it was the sum of all the instantiated stripe counts, which is also reasonable.</p></blockquote> <p>The following tests fail due to expecting a single value from ‘lfs getstripe’.<br/> sanity test 27i, 27w, 27A - <a href="https://testing.hpdd.intel.com/test_sets/5cc43d3c-23b8-11e7-8920-5254006e85c2" class="external-link" target="_blank" rel="nofollow noopener">https://testing.hpdd.intel.com/test_sets/5cc43d3c-23b8-11e7-8920-5254006e85c2</a></p> LU-9362

PFL: Files with multiple components should not return multiple values for ‘lfs getstripe’

Technical task LU-9349 Critical Resolved Fixed Zhenyu Xu James Nunez pfl Tue, 18 Apr 2017 22:38:22 +0000 Tue, 16 May 2017 06:17:48 +0000 Tue, 16 May 2017 06:17:48 +0000 Lustre 2.10.0 Lustre 2.10.0 0 6 <p>The patch of <a href="https://jira.whamcloud.com/browse/LU-9359" title="sanity test_27p: /mnt/lustre/d27p.sanity/f27p.sanity has size 4, not 80000004" class="issue-link" data-issue-key="LU-9359"><del>LU-9359</del></a> causes this issue.</p> <p>On further reflection, I think that always returning the parameters from the last instantiated component makes more sense than returning the sum of all the components. For example, it doesn't make sense to return the sum of the stripe sizes, or the sum of the pools (what would that even be?), or the sum of the stripe indices. The only one item that is even practical is the sum of the stripe counts, but I think this exception would be confusing, and even then it isn't clearly the best option.</p> <p>Returning the stripe count (and size, pool) of the last <b>instantiated</b> component allows applications that don't know about PFL or are copying the file to a non-PFL filesystem to create a file layout that has (approximately) the same performance as the the (normally) largest part of the file, and what would be used if more data is being written to the file (at least until it grows into the next component). This would preserve the "use best layout based on file size" property of PFL even if the file has to be flattened to use a plain layout.</p> <p>Bobijam, can you please provide a fix for this issue. As mentioned above, I think when asking for a simple value that the result from the last instantiated component. </p> <p>Bobi Jam (bobijam@hotmail.com) uploaded a new patch: <a href="https://review.whamcloud.com/26947" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/26947</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-9362" title="PFL: Files with multiple components should not return multiple values for ‘lfs getstripe’" class="issue-link" data-issue-key="LU-9362"><del>LU-9362</del></a> lfs: getstripe print last init-ed component info<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: b7e74920805416ba5eef6caa556d7c9a217bbd37</p> <p>Oleg Drokin (oleg.drokin@intel.com) merged in patch <a href="https://review.whamcloud.com/26947/" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/26947/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-9362" title="PFL: Files with multiple components should not return multiple values for ‘lfs getstripe’" class="issue-link" data-issue-key="LU-9362"><del>LU-9362</del></a> lfs: getstripe print last init-ed component info<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: da47e9c0320c9da342b7366e45a010e5a9ba239d</p> Gantt End to End LU-9359 Related LU-8998 LU-9424 Development Rank 1|hzzajj: Rank (Obsolete) 9223372036854775807