Bug 352827

Summary: KDE gets slow and malfunction once the NFS server is stopped
Product: [Frameworks and Libraries] kio-extras Reporter: Paulo Fidalgo <paulo.fidalgo.pt>
Component: NFSAssignee: Unassigned bugs mailing-list <unassigned-bugs>
Status: RESOLVED NOT A BUG    
Severity: normal CC: jjm
Priority: NOR    
Version: 18.04.3   
Target Milestone: ---   
Platform: Fedora RPMs   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Paulo Fidalgo 2015-09-17 09:19:14 UTC 
This is not a very easy to describe bug, although it happens every time.
If I mount an NFS drive (2TB almost full of data) and then stop the server (by shuting down the computer) KDE will start to become slow and not responding anymore, even in things like plasmashell.

Another test, is to put the computer to sleep and then shutdown the NFS server, you'll see a lot of problems arising.

Here is my fstab line:
htpc:/mnt/disk  /mnt/htpc                       nfs4    noauto,users  0  0

and my /etc/exports:
/mnt/disk       192.168.0.0/24(rw,no_subtree_check,async)



Reproducible: Always

Steps to Reproduce:
1. Mount an NFS drive
2. Stop NFS server
3. Observe KDE behaviour (Dolphin and PlasmaShell)
Comment 1 Jonathan Marten 2021-01-26 16:37:52 UTC 
This is not a KDE or Plasma problem.  If an NFS server is disconnected or shut down while a client has mounted any of its filesystems, any access to that filesystem will slow down or, in the worst case, hang indefinitely.  What precisely happens depends on the server's export options and the client's mount options, but the default in your case is 'hard' which means that access will be retried indefinitely.  Dolphin or any other application which needs to access the NFS filesystem can do nothing in this case.

Using the 'soft' mount option will give up eventually, but there is the possibility of data corruption.

The only way to recover, if you are able to get to a root shell, is to forcibly unmount any NFS filesystems.