Hi, I've seen this as well in a specific circumstance on my server. I run an M4000, Solaris 10 U4, Oracle 10.2.0.3, UFS filesystems managed by SVM (RAID 5), talking to Storedge 3510's and 6140's. I use RMAN to make backups of the database to a 3Tb filesystem mounted on /backup.
In particular, when I delete obsolete RMAN backups using the command RMAN> delete obsolete noprompt; For about 2 minutes after the delete returns control to the terminal, if I run df -k in another terminal, it will pause or hang while trying to report on /backup. I can do other operations on /backup. I can CD, ls files, du -sk directories. It's only the df -k that causes any problems. After about 2 minutes, the df -k completes, and fron them after I can run subsequent df -k with no problems. It's not dtrace or truss data, but I hope it helps. I'm off to run truss myself. Thanks for the tip Glen Parker On Fri, Feb 13, 2009 at 7:20 AM, Asif Iqbal <vad...@gmail.com> wrote: > On Thu, Feb 12, 2009 at 4:59 PM, Michael Schuster > <michael.schus...@sun.com> wrote: >> Asif Iqbal wrote: >>> >>> How do I find out why df -k is taking soo long to respond only sometimes? >> >> apply some analysing techniques: >> - define "soo long". > > more than a min. however I will try the truss method, like Chip > Bennett suggesting, > first to see where in the system call it is delaying > >> - what are you running 'df -k' on? the whole system or only a specific >> filesystem? > > just `df -k' , so yes the whole system > >> - is an NFS-mounted FS among the list of FSs examined? > > there is no nfs mounted fs in this host > >> - are there any messages in /var/adm/messages corresponding to the times >> where you see the slowdown? > > I am not sure exactly when it is slow. It happens at random time and delays > some > monitor script which calls `df -k' hourly and considers `df -k' failed > if it does not > respond in 60 secs. May be add a logic to the script to run some > `truss' or `dtrace' > at that time to collect some system state info > >> - describe the behaviour in a little more detail ... > > df -k does takes longer than 60 secs to result with an output, sometimes. > >> - what OS are you using? (this is not a joke question) > > Solaris 10 sparc update 3 on Sun Fire 420R with 4G mem > >> - what's the machine setup? how many users, etc... > > Usually one or two user login > >> - ... (you get the idea I hope) >> >> is this something related to DTrace, or is dtrace-discuss the first alias >> that came to mind? > > No. I am looking for the system calls when df -k is slow. Dtrace can be run > in daemon mode and if crafted correctly can collect tons of output *only* when > `df -k' takes longer than 60 sec to output > > >> >> HTH >> Michael >> -- >> Michael Schuster http://blogs.sun.com/recursion >> Recursion, n.: see 'Recursion' >> > > > > -- > Asif Iqbal > PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu > A: Because it messes up the order in which people normally read text. > Q: Why is top-posting such a bad thing? > _______________________________________________ > dtrace-discuss mailing list > dtrace-discuss@opensolaris.org > _______________________________________________ dtrace-discuss mailing list dtrace-discuss@opensolaris.org
