Best solution advice for backup to NAS over WAN

Question

What is the best solution for daily backup of Linux folder to NAS server over WAN? Here is the situation: My customer has expressed a wish that source code for his project must be backed up every day on my local server and then exported to his NAS. He gave me access to NAS via FTP protocol, and now I want to use cron scheduler for ftp upload to his server. Is this OK, and how is this done?

Answer 1

As per comments rsync is a good tool to use. Basic rsync usage simply mirrors a directory. For example:

rsync -a --delete /source/dir /backup/dir

Will make the backup directory match the source; if there is stuff in the backup that isn't in the source, it will be deleted (--delete), and if there is stuff that is in both, it will be updated in the backup if the timestamp in the source is more recent (i.e., the file has changed).

Note you can also use rsync via SSH if you don't have the remote directory locally mounted (and the NAS machine also runs an ssh server).

rsync -a --delete user@ip:/source/dir /backup/dir

This requires that you keep the mirror directory on your backup machine. If you want rolling backups, you could then archive and compress this:

tar -cjf  backup.tb2 /source/dir

This can then be extracted with tar -xjf backup.tb2. To prevent each backup from overwriting the last, you could use a timestamp:

tar -cjf backup.`date +%m%d%y`.tb2 /source/dir

This will produce a filename with a MMDDYY timestamp in it such as backup.030814.tb2.

So, that's a two line script you can execute daily via cron.

Answer 2

The simplest approach, assuming you want to back up folder /foo would be to create a simple little crontab to run rsync daily.

1. Create your crontab by running crontab -e. In the editor window that will appear, add this line (assuming your NAS is mounted locally, you can use ssh if not):

   @daily rsync -glprtu /foo /path/to/NAS/mount
   

2. Close the editor window. That's it, your folder will now be backed up to your NAS daily.

The rsync options used in this example are:

-g, --group                 preserve group
-l, --links                 copy symlinks as symlinks
-p, --perms                 preserve permissions
-r, --recursive             recurse into directories
-t, --times                 preserve modification times
-u, --update                skip files that are newer on the receiver

I suggest you read through man rsync for more options, it is a very powerful tool. You might, for example, be interested in

--delete                delete extraneous files from dest dirs
-z, --compress              compress file data during the transfer
-C, --cvs-exclude           auto-ignore files in the same way CVS does

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UPDATE: If you need to do this via ftp, I recommend you mount his NAS locally first:

1. Install curlftps

   sudo aptitude install curlftpfs
   

2. Edit /etc/fstab and add a line for the NAS:

   curlftpfs#ftpUsername:ftpPassword@ftp://ftpUrl /localDirectory fuse rw,uid=1000,umask=0777,user,suid,allow_other,exec,auto,utf8  0   1
   

Then, point your rsync command to the local mountpoint.