I have two nodes running CentOS Linux release 7.3.1611 (Core), one for computing (mu01), the other for storage (io01). As root, I mounted a directory /data on io01 to /data on mu01 by mount -t nfs -o vers=4 io01:/data /data. However, when I tried to write to the directory (as root or any other users), I got the following error message:
[root@mu01 data]# touch test1
touch: cannot touch 'test1': Read-only file system
mount returns (on mu01):
io01:/data on /data type nfs4 (rw,relatime,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=10.10.10.200,local_lock=none,addr=10.10.10.201)
cat /proc/mounts returns (on mu01):
io01:/data /data nfs4 rw,relatime,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=10.10.10.200,local_lock=none,addr=10.10.10.201 0 0
My /etc/fstab reads (on mu01):
#
# /etc/fstab
# Created by anaconda on Wed Jun 13 19:15:02 2018
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=f2f4003d-48fe-41db-af00-811e6bc8ec73 / xfs defaults 0 0
UUID=b01e3e3f-2c51-494e-b74b-f72e2ba0a1c1 /boot xfs defaults 0 0
UUID=9dbef967-1854-4079-96c5-8905674d446b swap swap defaults 0 0
my /etc/exports (on io01) reads:
/data 10.10.10.200 10.10.10.100(rw,no_root_squash,sync)
Edit 1: add more information on io01:
mount returns (on io01):
/dev/sdb1 on /data type xfs (rw,relatime,attr2,inode64,sunit=512,swidth=512,noquota)
cat /proc/mounts returns (on io01):
/dev/sdb1 /data xfs rw,relatime,attr2,inode64,sunit=512,swidth=512,noquota 0 0
/etc/fstab on io01:
#
# /etc/fstab
# Created by anaconda on Wed Jun 13 18:53:31 2018
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=57ae8e97-40cc-419f-bf6b-50e3de3256e2 / xfs defaults 0 0
UUID=ee35005e-9211-4bc6-9b5f-22fde47cc27d /boot xfs defaults 0 0
UUID=4273c2f3-7465-46af-8489-4f8f75848f6c swap swap defaults 0 0
/data is writable on io01.
