Home / server / Questions / 978504
In Process
KdgDev
Asked: 2019-08-09 07:34:06 +0800 CST

Delay on NFS mounts

  • 772

My setup:

3 machines, 2 client, 1 server. The server is redhat 7.6, the clients are ubuntu server 18.04.2.

The mount is a few dozen TB, the files placed on the clients are a few 100Gigs each.

The behavior I'm seeing is as follows:

A file gets placed on machine1. Another service then sees it appear on machine2 and tries to append something to it. However, the file on machine2 is not yet complete and this fails.

So there's some sort of latency going on there and I wonder how I should deal with that.

I'm getting the following output when checking the configuration of the mounts(anonymized):

machine1:~$ nfsstat -m
/mnt/dirA from <SERVER_IP>:/dirA
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

/mnt/dirB from <SERVER_IP>:/dirB
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

machine1:~$ cat /proc/mounts | grep <SERVER_IP>
<SERVER_IP>:/dirA /mnt/dirA nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0
<SERVER_IP>:/dirB /mnt/dirB nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0



machine2:~$ nfsstat -m
/mnt/dirA from <SERVER_IP>:/dirA
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

/mnt/dirB from <SERVER_IP>:/dirB
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

<SERVER_IP>:/dirA /mnt/dirA nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0
<SERVER_IP>:/dirB /mnt/dirB nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0

Which all seems pretty normal.

My question is: how can I measure this latency, perhaps monitor it, and deal with it? Is it inevitable? Is there a way to make it so the file won't be shown until complete? Or is there a better solution I haven't considered yet?

ubuntu

0 Answers