bdf command wait so long then get output

[napoly]

dear all,

when i try to run bdf command it takes so long then display all filesystems

when i run glance to watch CPU utilization i found that there were nothing consume the CPU

thanks

[Frank de Vries]

Bdf uses df -k, what do you get when you use
df -k ?

You are right, if CPU utilization is not an indication then we need to look at other
things like:

It usually indicates an underlying problem with logical volume or filesystem or ultimately a disk or diskcontroller.
Yes, it is rather a wide range unfortunately.

When it concerns filesystems it could be
that you have a stale NFS for instance.
Or just plain FS need fsck -m (sanity check)

When it concerns logical volume you could
have stale extents. Check all logical volumes
with lvdisplay -v /dev/xxx/xxx

An ioscan -fnC disk may reveal a problem at disk level, unclaimed devices etc..
However, some caution
is required. If you have a severe underlying hardware problem then your kernel could hang during an ioscan. Then best wait untill a safe time to do it.

Also check your syslog and dmesg for possible other errors or messages.

[Raj D.]

Napoly,

What happens if you type # bdf -l

If you have some nfs mount it can take such long time or hung.

cheers,
Raj.

[Fabian Briseño]

I agree with RAJ

for example lets say you have 2 servers
BOX A and BOX B

BOX A has a filesystem of BOX B mounted on it, if for some reason BOX B rebbots or crashes to name a couple of reasons

if You do a BDF on BOX A while BOX B is down you will get a very slow BDF becuase its trying to find for something that not there anymore

[Pupil_1]

Either bdf -l response time or the o/p of bdf you get after the long wait should help to decide the next step.

[Doug O'Leary]

Hey;

When I see a long responding bdf, it usually ends up being a problem w/nfs.

Faulty/failing disks could also cause the problem, but in my experience, nfs is the more likely culprit.

Hope that helps.

Doug

[A. Clay Stephenson]

This is normal bdf behavior and while NFS can certainly be a culprit, local filesystems that are under heavy use can also cause delays in bdf output. Essentially, you have a lower priority event waiting on a higher priority event. If you see these delays every time you run bdf then look for underlying problems but if you see these things occasionally then this is normal for a busy system.

[napoly]

thanks all

i think A.Caly has the right thinking as today i have tried to run bdf on the same server and every thinks is fine no delay