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<p class="MsoNormal">Thanks Andreas and Cory very helpful. -D will help for what I am using it for.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks!<o:p></o:p></p>
<p class="MsoNormal"> Keith <o:p></o:p></p>
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<p class="MsoNormal"><a name="_____replyseparator"></a><b>From:</b> Spitz, Cory James <cory.spitz@hpe.com>
<br>
<b>Sent:</b> Friday, March 20, 2020 12:57 PM<br>
<b>To:</b> Andreas Dilger <adilger@whamcloud.com>; Mannthey, Keith <keith.mannthey@intel.com><br>
<b>Cc:</b> lustre-discuss@lists.lustre.org; Koutoupis, Petros <petros.koutoupis@hpe.com><br>
<b>Subject:</b> Re: [lustre-discuss] DNE2 settings are not propagated?<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As Andreas says, it isn’t really recommended, but you can get sub-directories to inherit the striping by using the -D, --default option to `lfs mkdir` or `lfs setdirstripe`. From the man page:<o:p></o:p></p>
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<p class="MsoNormal"> -D, --default<o:p></o:p></p>
<p class="MsoNormal"> Set the default striping pattern of subdirectories. Newly cre-<o:p></o:p></p>
<p class="MsoNormal"> ated sub-directories will use the new default striping pattern,<o:p></o:p></p>
<p class="MsoNormal"> but existing sub-directories will not be affected. The newly<o:p></o:p></p>
<p class="MsoNormal"> created sub-directories will also inherit the specified default<o:p></o:p></p>
<p class="MsoNormal"> striping pattern. Only default stripe count is supported for<o:p></o:p></p>
<p class="MsoNormal"> now.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> Note that striping all directories across all MDTs by default is<o:p></o:p></p>
<p class="MsoNormal"> not recommended at this time, as the clients will have to do<o:p></o:p></p>
<p class="MsoNormal"> more RPCs to create and access each directory, hurting perfor-<o:p></o:p></p>
<p class="MsoNormal"> mance rather than improving it. Default striped directories are<o:p></o:p></p>
<p class="MsoNormal"> preferred for cases where large subdirectories will be created<o:p></o:p></p>
<p class="MsoNormal"> (e.g. file-per-process job output directories).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">-Cory<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-left:.5in">On 3/20/20, 2:33 PM, "lustre-discuss on behalf of Andreas Dilger" <<a href="mailto:lustre-discuss-bounces@lists.lustre.org">lustre-discuss-bounces@lists.lustre.org</a> on behalf of
<a href="mailto:adilger@whamcloud.com">adilger@whamcloud.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:.5in">On Mar 20, 2020, at 13:02, Mannthey, Keith <<a href="mailto:keith.mannthey@intel.com">keith.mannthey@intel.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:.5in">I am doing some work with Lustre 2.13 (Downloaded from Whamcloud) and DNE 2 there are 6 MDTs.
<br>
<br>
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"<br>
[root@colts52-clx01 for-test]# lfs getdirstripe TEST<br>
lmv_stripe_count: 6 lmv_stripe_offset: 1 lmv_hash_type: fnv_1a_64<br>
mdtidx FID[seq:oid:ver]<br>
1 [0x2c0000400:0x5:0x0]<br>
5 [0x300000403:0x5:0x0]<br>
3 [0x340000403:0x5:0x0]<br>
0 [0x200000403:0x5:0x0]<br>
4 [0x240000402:0x5:0x0]<br>
2 [0x280000401:0x5:0x0]<br>
[root@colts52-clx01 for-test]# mkdir TEST/now<br>
[root@colts52-clx01 for-test]# lfs getdirstripe TEST/now/<br>
lmv_stripe_count: 0 lmv_stripe_offset: 2 lmv_hash_type: none<br>
"<br>
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Directory stripping settings are not being propagated. Is this expected? <o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:.5in">Yes, this working as designed. It isn't necessarily good for all directories to be striped, as that adds overhead without necessary improving performance.<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:.5in">The current recommendation is that DNE should be used for e.g. a top-level directory to distribute files and subdirectories across MDTs, or in the case of large directories with millions of files.<o:p></o:p></p>
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<p class="MsoNormal" style="margin-left:.5in"><span style="color:black">Cheers, Andreas<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><span style="color:black">--<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><span style="color:black">Andreas Dilger<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><span style="color:black">Principal Lustre Architect<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:.5in"><span style="color:black">Whamcloud<o:p></o:p></span></p>
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