[CentOS] nfs causes Centos 7.7 system to hang

On 12/26/19 11:15 AM, Nikolaos Milas wrote:
> Hello,
> 
> MERRY CHRISTMAS to all in list!
> 
> After I upgraded to latest: CentOS Linux release 7.7.1908 (Core) I am
> facing nfs crashes which cause the system to hang frequently.
> 
> This is caused by cp to nfs-mounted shares.
> 
> Below is dmesg output; you will see call traces. These cause system to
> gradually overload:
> 
> [root at hesperia1 ~]# top
> top - 10:09:40 up 10:16,  1 user,  load average: 53.66, 54.13, 52.98
> Tasks: 475 total,   2 running, 436 sleeping,   0 stopped,  37 zombie
> %Cpu(s):  0.1 us,  0.6 sy,  0.0 ni, 99.2 id,  0.0 wa,  0.0 hi, 0.0 si, 
> 0.1 st
> KiB Mem :  3879928 total,   813504 free,  1733216 used,  1333208 buff/cache
> KiB Swap:  4063228 total,  4062708 free,      520 used.  1797264 avail Mem
> 
> and finally hangs showing messages (which I have not recorded precisely)
> in the CLI login screen like "System out of memory". Then I have to reboot.
> 
> I tried to downgrade nfs-utils and rpcbind to earlier versions (in case
> there is a bug in latest ones), but I couldn't:
> 
>    [root at hesperia1 ~]# yum downgrade rpcbind-0.2.0-47 nfs-utils-1.3.0-61
>    Loaded plugins: fastestmirror
>    Loading mirror speeds from cached hostfile
>      * base: ftp.ntua.gr
>      * epel: mirrors.daticum.com
>      * extras: ftp.ntua.gr
>      * updates: ftp.ntua.gr
>    No package rpcbind-0.2.0-47 available.
>    No package nfs-utils-1.3.0-61 available.
>    Error: Nothing to do
> 

...


you don't have to specify versions, just

yum downgrade rpcbind nfs-utils

and then yum will work out the versions by itself, and their
dependencies - in this case, it appears that you'll have to downgrade
some libraries as well.

HTH,
Kay