On 2009-12-23, at 04:11, Andrea Pieretti wrote: > Dear Andreas, sorry for the delay, > I work with Miguel, so i'll write for him. > > We have one question, > is it possible (safe) to use debugfs on a mounted Lustre filesystem?
Yes, this is safe unless you open the filesystem with "-w" (write mode). Without that you shouldn't be able to modify the filesystem, and it is safe. > Andreas Dilger wrote: >> On 2009-12-16, at 06:28, Miguel Molowny Lopez wrote: >> >>> we are running lustre 1.8.1.1 on our storage cluster based on IB. >>> >>> We are building a "bulldozer" for a scratch area and we have found >>> an >>> odd behaviour in the e2scan utility (maybe a bug or a ... "defined >>> behaviour" we don't know about). >>> >>> We have reproduced this behavior several time and we are having >>> these >>> results: >>> - we run e2scan on the MDT to have the files newer than 3 days ago: >>> command line used was like: >>> * e2scan -l -N '2009-12-13' /dev/mapper/mdt >>> or: >>> * e2scan -l -n /tmp/file.timestamp /dev/mapper/mdt >>> where file.timestamp has been created with the date of >>> 3 days ago using touch >>> The result is sorted and saved in a file called: 3daysago.list >>> - we then run another e2scan looking for files newer than 2 days ago >>> using the same command line and the result is sorted and saved in >>> a file called: 2daysago.list >>> >>> The problem is that there are files whose last modification time is >>> before the date at which we run the two e2scan commands (they were >>> not >>> modified during the run of e2scan) _BUT_ they appear only in the >>> list >>> 3daysago.list. Here is an example: >>> >>> - first run of e2scan at: Dec 15 16:20 (produce list 3daysago.list) >>> - second run of e2scan at: Dec 15: 16:50 (produce list >>> 2daysago.list) >>> - file: /scratch/foobar.txt has mtime=ctime = Dec 14 03:19 >>> >>> This file is still on filesystem after the run of the two e2scan >>> cmd >>> well, this file appears only in the 3daysago.list. And this happen >>> for >>> a _LONG_ list of files. >>> >> >> >> This is definitely odd. It is worthwhile to check what the timestamp >> is on the MDS, via "debugfs -c -R 'stat foobar.txt'", in addition to >> checking via "stat /scratch/foobar.txt" in the filesystem. >> >> Cheers, Andreas >> -- >> Andreas Dilger >> Sr. Staff Engineer, Lustre Group >> Sun Microsystems of Canada, Inc. >> >> _______________________________________________ >> Lustre-discuss mailing list >> [email protected] >> http://lists.lustre.org/mailman/listinfo/lustre-discuss >> > > -- > +------------------------------------------------------- > + Andrea Pieretti > + C.A.S.P.U.R., > + Via dei Tizii, 6b > + 00185 Roma ITALY > + tel: +39-06-44486712 > + mob: +39-328-4280841 > + fax: +39-06-4957083 > + e-mail: [email protected] > + http://www.caspur.it > +------------------------------------------------------- > + > + "Nitwit! Blubber! Oddment! Tweak!" > + > + Albus Percival Wulfric Brian Dumbledore > +------------------------------------------------------- > > _______________________________________________ > Lustre-discuss mailing list > [email protected] > http://lists.lustre.org/mailman/listinfo/lustre-discuss Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
