There was a problem with our raid controller this morning, raid array was degraded ( I reinstalled the hard drive and its state was <b>rebuilding</b> right after that ) and from messages log, i saw many warnings like this: <br>
<br><i>Jan 26 13:59:13 OST6 kernel: Lustre: 9589:0:(filter.c:1363:filter_parent_lock()) lustre-OST0006: slow parent lock 49s<br>Jan 26 13:59:13 OST6 kernel: Lustre: 9589:0:(filter.c:1363:filter_parent_lock()) Skipped 10 previous similar messages<br>
Jan 26 13:59:13 OST6 kernel: Lustre: 9638:0:(filter_io.c:398:filter_preprw_read()) lustre-OST0006: slow preprw_read setup 34s</i><br><br>I have never seen <i>slow parent lock </i>or <i>preprw-read </i>before. Maybe everything is going down fast and severely, Do all you guys have any ideas for my situation ? <br>
<br>Just guess, i think it was impacted by performance decreasing issue during rebuild raid array.<br><br>Best regards <br><br><div class="gmail_quote">On Tue, Jan 26, 2010 at 9:05 AM, Lex <span dir="ltr"><<a href="mailto:lexluthor87@gmail.com">lexluthor87@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div><div></div><div class="h5"><br><br><div class="gmail_quote">On Tue, Jan 26, 2010 at 12:07 AM, Mark Hahn <span dir="ltr"><<a href="mailto:hahn@mcmaster.ca" target="_blank">hahn@mcmaster.ca</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
Sorry Erik if i'm rising such a "bad" question, could u tell me more about<br>
OST journal device ? I even don't know what it is as well as haven't seen it<br>
before, in the lustre manual.<br>
</blockquote>
<br></div>
an OST is an ext3-ish filesystem associated with some OST server processes.<br>
since it's basically ext3, the properties of ext3 apply, including the use of a journal, and the ability to use an "external" journal device.<br>
</blockquote></div><br></div></div>I think we don't have any separate or external journal device like you said. So could anyone tell me exactly what stuff make the warning about slow xxx in our OST logs like i described above is ? Is there any role of lustre in this situation ? And how? What is the relationship with journal device and my problem ? <br>
<br>Best regards <br>
</blockquote></div><br>