Red Hat Knowledgebase

Problem: Large FTP uploads do not complete reliably. Since many public FTP servers (such as dropbox.redhat.com) use blind upload directories, failed uploads to these servers must be resumed from the beginning.

Cause: Some FTP clients cannot properly handle files 2 GB or larger. Additionally, mild network congestion is more likely to disrupt uploads that take a long time to complete.

Recommendation: Use the split command to break a large file into smaller chunks. If a single chunk upload fails, only that chunk needs to be repeated.

Example:

[root@localhost example]# ll
total 4538044
-rw-r--r-- 1 root root 4642406400 May 8 15:41 reallybigfile.tar.bz2
[root@localhost example]# split -b 512m -d reallybigfile.tar.bz2
reallybigfile.tar.bz2.part
[root@localhost example]# ll
total 9076144
-rw-r--r-- 1 root root 4642406400 May 8 15:41 reallybigfile.tar.bz2
-rw-r--r-- 1 root root 536870912 May 8 15:49 reallybigfile.tar.bz2.part00
-rw-r--r-- 1 root root 536870912 May 8 15:50 reallybigfile.tar.bz2.part01
-rw-r--r-- 1 root root 536870912 May 8 15:50 reallybigfile.tar.bz2.part02
-rw-r--r-- 1 root root 536870912 May 8 15:51 reallybigfile.tar.bz2.part03
-rw-r--r-- 1 root root 536870912 May 8 15:51 reallybigfile.tar.bz2.part04
-rw-r--r-- 1 root root 536870912 May 8 15:52 reallybigfile.tar.bz2.part05
-rw-r--r-- 1 root root 536870912 May 8 15:52 reallybigfile.tar.bz2.part06
-rw-r--r-- 1 root root 536870912 May 8 15:52 reallybigfile.tar.bz2.part07
-rw-r--r-- 1 root root 347439104 May 8 15:52 reallybigfile.tar.bz2.part08

This example splits a 4.6 GB file into 9 parts, each no larger than 512 MB. The parts can be reassembled using cat.