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-11829 Lustre <p>Currenly a PCC backend can provide caching services for both RW-PCC and RO-PCC which both use lhsmposix naming structure as follows:</p> <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java"> <span class="code-quote">"%04x/%04x/%04x/%04x/%04x/%04x/"</span> DFID_NOBRACE </pre> </div></div> <p>However, sharing the same naming structure may cause some confusions. For example, when RO-PCC cache a HSM archived file (not HSM released), it may confuse the user that whether the cached file object in the PCC device is RO-PCC cached file or a HSM archive. Moreover, a HSM remove request maybe delete the RO-PCC cached file wrongly.<br/> To solve this problem, we add a suffix .rdonly for RO-PCC naming strcuture to distingush from the RW-PCC and HSM solution:</p> <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java"> <span class="code-quote">"%04x/%04x/%04x/%04x/%04x/%04x/"</span>DFID_NOBRACE<span class="code-quote">".rdonly"</span> </pre> </div></div> LU-11829

Separate the naming structure between RW-PCC and RO-PCC

Technical task LU-12714 Minor Open Unresolved Qian Yingjin Qian Yingjin PCC Thu, 27 Dec 2018 09:16:18 +0000 Fri, 17 Jul 2020 00:43:52 +0000 0 4 <p>Note also that the current lhsmtool_posix naming convention for objects is not very good, and should be avoided for new deployments. It currently puts the low part of the FID at the top of the directory tree, and the high part of the FID in the lower directories. This means that each directory leaf will only ever have a single filename in it until many billions of files are archived.</p> <p> Instead, the naming should be changed to do the opposite - put the high word of SEQ at the top of the directory tree, and the low word of the OID at the bottom. This will keep some reasonable number of objects in each leaf directory (eg. 65000) and keep a more compact directory tree. </p> <p>If this needs a change to the POSIX copytool, then for compatibility it should create a config file or marker at the top of the tree (eg.<tt>lhsm_posix_v2</tt>) and check for that at startup to determine if the new naming format should be used or the old one. </p> <p>Hi Andreas,</p> <p>Thanks for you comments.</p> <p>I think we should create a new ticket to discuss and improve the usage efficiency of the current lhsmtool_posix naming convention for objects.</p> <p> </p> <p>Regards,</p> <p>Qian</p> <p>Yingjin Qian (qian@ddn.com) uploaded a new patch: <a href="https://review.whamcloud.com/33942" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/33942</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-11829" title="Separate the naming structure between RW-PCC and RO-PCC" class="issue-link" data-issue-key="LU-11829">LU-11829</a> pcc: Separate the naming between RW-PCC and RO-PCC<br/> Project: fs/lustre-release<br/> Branch: pcc<br/> Current Patch Set: 1<br/> Commit: 4e0acfaf9d892db32da4fa99dc2665f8e28ac979</p> <p>Yingjin Qian (qian@ddn.com) uploaded a new patch: <a href="https://review.whamcloud.com/38309" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/38309</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-11829" title="Separate the naming structure between RW-PCC and RO-PCC" class="issue-link" data-issue-key="LU-11829">LU-11829</a> pcc: Use different fnames for RW-PCC and RO-PCC modes<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: dff3b6ab81c8e11cf79e4f67447fc884c7747aa5</p> Related Development Rank 1|i008qn: Rank (Obsolete) 9223372036854775807