Hi Dan,<br><br>It should be completely safe to use a volume while fix-layout is going on after add-brick.<br><br>Even in case of fix-layout after remove brick, there is no harm in using volume while fix-layout is going on, but the issue is, the new entry creates (like creat(),mkdir(),mknod(),symlink() etc) would fail if its parent path has not yet undergone 'fix-layout'. If your application is creating a new directory for its operation, you can surely have a working volume while fix-layout operations are going on.<br>
<br>About the number of entries shown as extra, it is an issue with rebalance operation as such because the 'readdir()' operation happens on a directory while its layout gets fixed, hence the way the 'offset' is calculated internally may differ, and hence we would end up reading the same entry again some times.<br>
<br>Regards,<br>Amar<br><br><div class="gmail_quote">On Sun, Aug 7, 2011 at 5:50 PM, Dan Bretherton <span dir="ltr"><<a href="mailto:d.a.bretherton@reading.ac.uk">d.a.bretherton@reading.ac.uk</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;">
Hello All-<br>
I regularly increase the size of volumes using "add-brick" followed by "rebalance VOLNAME fix-layout". I usually allow normal use of an expanded volume (i.e reading and writing files) to continue while "fix-layout" is taking place, and I have not experienced any apparent problems as a result. The documentation does not say that volumes cannot be used during "fix-layout" after "add-brick", but I would like to know for certain that this practice is safe.<br>
<br>
I have a similar question about using volumes during"fix-layout" after "remove-brick"; is this a safe thing to do? Being cautious I assume not, but it would be very useful to know if files can actually be safely written to a volume in this situation. This weekend I had to shrink a volume using "remove-brick", and I am currently waiting for "fix-layout" to complete before copying the files from the removed brick into the shrunk volume. The problem is that there are 2.5TB of data to copy, but fix-layout is still going after two days. I was banking on completing the shrinking operation over the weekend and making the volume available for use again on Monday morning. Therefore I would really like to know if I can start the copy now while fix-layout is still going on.<br>
<br>
Incidentally, is there a way to estimate how long fix-layout will take for a particular volume? I don't understand why fix-layout is taking so long for my shrunk volume. According to the master_list.txt file I created recently during the GFID error fixing process, the volume in question has ~1.2 million paths, but "fix-layout VOLNAME status" shows that twice this number of layouts have been fixed already.<br>
<br>
Regards<br>
Dan.<br>
<br>
-- <br>
Mr. D.A. Bretherton<br>
Computer System Manager<br>
Environmental Systems Science Centre<br>
Harry Pitt Building<br>
3 Earley Gate<br>
University of Reading<br>
Reading, RG6 6AL<br>
UK<br>
<br>
Tel. +44 118 378 5205<br>
Fax: +44 118 378 6413<br>
<br>
______________________________<u></u>_________________<br>
Gluster-users mailing list<br>
<a href="mailto:Gluster-users@gluster.org" target="_blank">Gluster-users@gluster.org</a><br>
<a href="http://gluster.org/cgi-bin/mailman/listinfo/gluster-users" target="_blank">http://gluster.org/cgi-bin/<u></u>mailman/listinfo/gluster-users</a><br>
</blockquote></div><br>