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Re: Mount path

 
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juno2
Super Advisor

Mount path

Host A mount the path on Host B , now I have reboot the Host B but didn't umount the path.
When I run the command "bdf" , then the system nearly hang , how can i solve it except reboot the host A ? thx
8 REPLIES 8
Pete Randall
Outstanding Contributor

Re: Mount path

At this point, the only thing you can try is to unmount the path on hostA. If you can get it to unmount, then you can remount it. If it won't unmount, you're going to have to reboot.


Pete


Pete
Johnny Damtoft
Regular Advisor

Re: Mount path

You might have to wait until host B gets back online again so you can unmount your mountpoint.

I have been in the samt situartion, and my only solution was to reboot if the NFS server did not get back online.

Robert-Jan Goossens
Honored Contributor

Re: Mount path

If You can not umount it on A, you will have to reboot.

Robert-Jan.
T G Manikandan
Honored Contributor

Re: Mount path

Wait until the other machine boots up!!
RolandH
Honored Contributor
Solution

Re: Mount path

Hi JunoTWO,

if you use this nfs mount mainly for read operations you should change your mount option in your /etc/fstab file to soft the default is hard mount option.

See what the man page writes mount_nfs(1M)

...
Hard vs. Soft
File systems that are mounted read-write or that contain executable files should always be mounted with the hard option. Applications using soft mounted file systems may incur unexpected I/O errors.

To improve NFS read performance, files and file attributes are cached. File modification times get updated whenever a write occurs. However, file access times may be temporarily out-of-date until the cache gets refreshed. The attribute cache retains file attributes on the client. Attributes for a file are assigned a time to be flushed. If the file is modified before the flush time, then the flush time is extended by the time since the last modification (under the assumption that files that changed recently are likely to change soon). There is a minimum and maximum flush time extension for regular files and for directories. Setting actimeo=n sets flush time to n seconds for both regular files and directories.


Please see also the bg|fg in mount_nfs(1M)option.

So if you have mainly read operation on your nfs mount you should use the soft options.

another problem is, if you use the default value for nfs mounts (fg,hard) and you have one nfs mount in your /etc/fstab that will mount from system B, which is down. And system A is at startup. System A will stop booting until system B is up and the filesystem exported by system B. But now system A will boot further.


HTH
Roland
Sometimes you lose and sometimes the others win
Massimo Bianchi
Honored Contributor

Re: Mount path

Hi,
check on both hosts the file /etc/rmnttab and delete the entry relative to the other hosts.


Second, if you can shut down the nfs.client services and clean the /etc/mnttab.

Massimo
juno2
Super Advisor

Re: Mount path

I tried umount the path , but pop the message :umount2: Device or resource busy
umount: /usr/dvd/: Illegal seek: " ,
besised , i can't find the file /etc/rmnttab in my system , is there other method except reboot hostA ? thx
Rajeev  Shukla
Honored Contributor

Re: Mount path

Hi,
First thing is get the HostB up which serves as the NFS server if that doesn't solve the problem on HOSTA then stop the nfs.client and nfs.server on HostA and restart nfs.server and nfs.client
these startup and shutdown scripts are in /sbin/init.d
That should help you.