Cannot copy files > 2 GB to NFS mount on Ubuntu 12.04 server

taylorkh · 08-30-2013, 08:48 AM

My "server" is really just an overgrown hard drive used for backup. It has 3 x 1 TB and 1 x 2 TB individual drives - no RAID. All are accessible via NFS, Samba and SSH.

The machine has run Ubuntu 8.04 and 10.04 just fine for many years. Recently I upgraded to Ubuntu 12.04 (yes I know I should reinstall rather than upgrade but I may be doing that or decommissioning in near future so I said what the heck). The upgrade seemed to work fine.

Today I noticed that I could not copy a file > 2 GTB to the sever via NFS. I get the message "Error writing file: File too large." I observed this in Gnome Commander and Nautilus on my CentOS 6 workstation. Here are some of the key configuration files.

fstab on the Ubuntu server

Quote:

# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
/dev/sda1 / ext3 errors=remount-ro 0 1
/dev/sda3 /data0 ext4 defaults 0 2
/dev/sdb1 /data1 ext4 defaults 0 2
/dev/sdc1 /data2 ext4 defaults 0 2
/dev/sda2 none swap sw 0 0
/dev/sdd1 /data3 ext4 defaults 0 2

exports on the Ubuntu server

Quote:

# /etc/exports: the access control list for filesystems which may be exported
# to NFS clients. See exports(5).
#
# Example for NFSv2 and NFSv3:
# /srv/homes hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)
#
# Example for NFSv4:
# /srv/nfs4 gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)
# /srv/nfs4/homes gss/krb5i(rw,sync,no_subtree_check)

/data0 192.168.0.112(rw,no_root_squash,async)
/data1 192.168.0.112(rw,no_root_squash,async)
/data2 192.168.0.112(rw,no_root_squash,async)
/data3 192.168.0.112(rw,no_root_squash,async)

Mounting script on the CentOS machine

Quote:

sudo mount taylor10:/data0 /t10/data0
sudo mount taylor10:/data1 /t10/data1
sudo mount taylor10:/data2 /t10/data2
sudo mount taylor10:/data3 /t10/data3

A couple of notes: The Ubuntu machine is listed in /etc/hosts as taylor10. The CentOS machine has a reserved address of 192.168.0.112 and is the only machine which will access nfs on the server.

I have no problems writing smaller files to the server. I CAN write larger files between drives on the server when I access the server with ssh or vnc. I CAN copy files > 2 GB from the CentOS machine to the server over a "connect to sever by SSH" connection in Nautilus or Gnome Commander. I CAN write files > 2 GB to the server using Samba on a Windows virtual machine.

There is probably an easy configuration tweak of NFS to fix this but I have not been able to find it in my searching. This seems to be an issue caused by the upgrade to Ubuntu 12.04. Any advice?

TIA,

Ken

eSelix · 08-30-2013, 10:06 AM

Maybe you connected with version 2 of NFS (which does not support files larger than 2GB). Check "mount -lv" on client. If yes, then force using other version by "mount -t nfs -o vers=3 ..." or "mount -t nfs4 ..." and/or disable other versions on server.

taylorkh · 08-30-2013, 12:09 PM

Thanks eSelix,

mount -lv did not show me any version information when I was connected to my server. I created a 12.04 server from scratch on VMware. I can mount it and copy > 2 GB files to it. It shows me version=4 when I issue the mount -lv command. I think I will uninstall and reinstall nfs on the physical server and see what happens. If that does not work I am planning to swap some drives around and will reinstall the server OS.

Thanks again,

Ken

taylorkh · 08-30-2013, 12:25 PM

Well I spoke (posted) too soon

I was copying my 4 GB test file with gnome-commander. The progress bar showed 3+ GB transferred and I declared victory. After making the prior post I found that the transfer had still not completed and as I poked around my gui on the CentOS machine froze. I remoted in and rebooted. I have examined the virtual server and I find that only 2 GB transferred to it. I may setup a test CentOS server and see what happens.

Ken

taylorkh · 09-03-2013, 07:58 AM

I threw in the towel on testing this with VMWare. I installed CentOS 6.4 on an old Pentium 4 box about the same vintage and horsepower as my server. I could copy files > 2 GB to an NFS mount but the throughput was horrible. System Monitor showed a good flow for about 100 MB then the flow would drop to zero for about the same amount of time then back up for another 100 MB. The machine only has a 100 Mb/s network card but it was not using it to its capacity.

And for my next trick I installed Ubuntu 12.04 server on the old test PC. Setup NFS same as I had done on the VMWare machine. I can copy files > 2 GB and the data flow flat lines at the limit of the 100 Mb/s NIC.

Finally I installed Ubuntu 12.04 server on a new hard drive (WD Caviar Blue 500 GB) in the server. NFS works great! I can achieve speeds > 70 MB/s over my gigabit network. I then added back 3 of the original server drives (2 x 1 TB WD Green and 1 x 2 TB WD Green) and a new Toshiba 2 TB (Intellipower or something like that). It seems that all this time I have been hard drive limited in throughput. I know that the WD Green drives are not the fastest but I can write to them at only a little over half what the WD Blue will do. So now I am good to go. I only have to figure out what to store where on my overgrown hard drive.

Ken