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

by on March 6, 2007 · 5 comments· LAST UPDATED March 6, 2007

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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.

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{ 5 comments… read them below or add one }

1 gary June 9, 2007 at 10:39 am

Thank you for adding this information. It proved very helpful.


2 Leonard Lilla September 10, 2007 at 1:40 am


Well, I had been looking for this a long time. I don’t know why I never landed on this site before. But I am here and thank you for this post. Saves me a lot of trouble!



3 John January 27, 2008 at 10:42 pm

Did you format the drive using the NTFS format? it sounds to me the drive is formatted as FAT32, which does not allow for files larger than 2GB


4 DanD March 3, 2008 at 3:22 pm

FAT32 allows files larger than 2GB, up to almost 4GB

“You cannot create a file larger than (2^32)-1 bytes (this is one byte less than 4 GB) on a FAT32 partition.”



5 nisarg March 4, 2008 at 6:49 pm

Hi, thanks!
Thats been very useful.
I was stuck at 2GB trying to rescue 60gb disk, writing to an NFTS partition mounted via SMBMOUNT.
Just one question. With this lfs option – is there any limits at all? i hope not


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