# nfsd in D-state

## akshimassar

Hello, guys.

I have a problem with my nfs. My home dir (desktop) is mounted via nfs (from router). Both (desktop and router) runs gentoo, connected over gigabit switch.

Problem can be reproduced by running firefox at desktop. As I assume, firefox generate many io and nfs (nfsd at router) fall into D-state from time to time. nfsd (all 8 threads) could stay in D-state up to 10-20 seconds.

Everything was O.K. until I changed hdd at router (soft RAID-0 to 1 hdd) and upgraded to nfs4. It was some time ago and now I cannot fall back to previous configuration.

Here is my config:

```
exports:

/home/akshi-desktop/ 10.255.0.13(rw,no_subtree_check,no_root_squash)

fstab:

10.255.0.1:/home/akshi-desktop/home/akshimassar /home/akshimassar   nfs      rw,nfsvers=3,proto=tcp,noatime         0 0
```

And call trace (got it with magic sysrq) when all nfsd in d-state. Can anyone say something useful about this log?

What can I test to determine a reason?

Copying big file over nfs is about 50MB/s.

Copying (to router) 20MB files over nfs takes about 3secs on each file. 2 seconds on copying date and 1 sec pause.

Yeah, after "upgrade" creating a little files is very slow.

Thank you for your help.

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## akshimassar

No ideas?   :Sad: 

On my router, еvery process who writes a disk fall to D-state from time to time. E.g. nfsd, kjournald, jbd2/sda4-8. And four last lines are always the same:

```

? kthread+0x9e/0xb0

? kernel_thread_helper+0x4/0x10

? kthread_worker_fn+0x130/0x130

? gs_change+0xb/0xb

```

May be something wrong with my kernel config or hdd?

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## akshimassar

Found something similar: https://bugzilla.redhat.com/show_bug.cgi?id=828521

But I used TCP

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