Samba mount and access large 2GB+ files from share or NAS device

Q. I’m using NAS server share to make a backup of my webserver. However samba is not allowing me to backup of large files (2GB+).

My Samba share mount command is as follows:
smbmount // /datanas -o username=LOGINNAME,password=LOGINPASSWORD

Now if I copy file called /var/log/httpd/access.log (which is 3.5 GB file):
cp /var/log/httpd/access.log /datanas

I get ab error – file size limit exceeded

How do I solve this problem and copy large files to NAS samba share?

A. Linux kernel use smbfs.ko/smbfs.o module and it does not support file sizes greater than 2 GB. This is well known problem.

Mount your NAS samba share with lfs (large file system) option. General syntax is as follows:
smbmount //Hostname/Username /local/mountpoint -o username=username,password=password,lfs

For example:
# smbmount // /datanas -o username=LOGINNAME,password=LOGINPASSWORD,lfs


  • // : Server and Share name
  • /datanas : Local mount point
  • -o username=LOGINNAME,password=LOGINPASSWORD,lfs : Specify login, password and lfs options

Now you should be able to copy large files w/o a problem.

Posted by: SXI ADMIN

The author is the creator of SXI LLC and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.