doubt in NFS mounted filesystem in linux

Linux and Unix-Like Red Hat
1

Hi,
I have some filesystem which is nfs mounted and shared to other servers.
Nfs server name= nfsserver (here filesystem is locally mounted)
server name where filesystem is shared = sharedserver1 and sharedserver2
filesystem which is shared = /filesystem1
when i am checking utilization by command df -k, there is some difference in space utilized for "used" and "Available". Could you please let me know is it normal or some issue with servers.
OS = Linu

 
details on NFS server
> df -k /filesystem1
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mapper/vg_optibm-lv_optibm
                     103208224  43843692  54121860  45% /filesystem1
> grep "/filesystem1" /etc/fstab
/dev/vg_optibm/lv_optibm        /filesystem1                ext3    defaults        1 2

 
details on sharedserver1
> df -k /filesystem1
Filesystem           1K-blocks      Used Available Use% Mounted on
157.241.44.26:/      103208224  43842944  54122592  45% /filesystem1
> grep "/filesystem1" /etc/fstab
157.241.44.26:/         /filesystem1                nfs4    rw,hard,intr    1 2

 
details on sharedserver2
> df -k /filesystem1
Filesystem           1K-blocks      Used Available Use% Mounted on
157.241.44.26:/      103208224  43843776  54121760  45% /filesystem1
> grep "/filesystem1" /etc/fstab
157.241.44.26:/         /filesystem1             nfs4     rw,hard,intr    1 2

Thanks,
Anshu

2

Not sure... but do realize that NFS is NOT a cluster aware filesystem. That is, it's not a shared filesystem... it's a network file system (NFS). The view of each client is not guaranteed. I guess you could say that NFS tries to keep from flying apart but doesn't try to keep every client's view integral. If you need true live shared storage, look into a cluster aware filesystem (e.g. ocfs2, GFS2, Veritas, etc.)