Also, while I have never tried it, sysdig looks interesting, and might be able to do what you are looking for.
http://www.sysdig.org/ rgt Whitehead Network/System Administrator ----- On Sep 1, 2016, at 4:54 PM, Rob Taylor(Whitehead) [email protected] wrote: > Have you tried iotop? > It will tell you what processes are moving the most disk io at any given > instant. > Still might not get you what you want, but it might make it easier to narrow > down. > > rgt > > Whitehead Network/System Administrator > > ----- On Sep 1, 2016, at 3:05 PM, Daniel Feenberg [email protected] wrote: > >> Apparently heavy random I/O overloaded our fileserver last week, and >> response was very slow. We solved the problem with additional spindles, >> but we are curious to know which process is doing the random I/O. Perhaps >> we could approach that user with an offer to help improve their turnaround >> time by changing the code. Our users are mostly inexperienced students so >> the possibility of suboptimal code is certainly there. Most usage is >> sequential access to very large files that does not load the fileserver >> much at all so this has been a new experience for us. >> >> We can easily track bytes/second but a process doing random I/O may use >> very few bytes/second, but still occupy much of the fileservers capacity, >> so it hasn't been fruitful to identify the processes doing the most reads >> and writes. During the period of overload, few disks were showing more >> than kilobytes/second of read or write, yet iostat revealed that several >> disks were continuously at 100%. >> >> A program such as iostat will tell us which physical disk is busy, lsof >> will tell us which file is open by which process, netstat and nfstat will >> give aggregate statistics over all processes, but I can't find a program >> that will tell us which process is occupying the fileservers attention >> with expensive requests. >> >> We couldn't replace all the disks with SSD, but might be able to provide >> SSD for some files, if we could identify the culprits. >> >> Daniel Feenberg >> >> _______________________________________________ >> bblisa mailing list >> [email protected] >> http://www.bblisa.org/mailman/listinfo/bblisa > > _______________________________________________ > bblisa mailing list > [email protected] > http://www.bblisa.org/mailman/listinfo/bblisa _______________________________________________ bblisa mailing list [email protected] http://www.bblisa.org/mailman/listinfo/bblisa
