I plan to move from linux o/s a directory which is mounted on SAN(offboard) to external storage for backup. The dir size is 14TB.

I do have experience moving files in/out using rsync but never done this with large size directories/files like now.

The directories are laid down in terms on year/month/days/hours hierarchy and support raw-logs for analysis.

**Problem**

So with the above told, due to resource restrictions I'm not able to move complete 14TB to external/backup storage space. The backup space I have currently is max 8 TB. So is there a command or switch / parameter i can tell rsync to only copies files to the mentioned size i.e TB only.

NOTE I don't care less about the file nature its just the beyond certain size i don't want to move any data.

Perhaps rsync is not the best tool for this.

You are not doing a sync, you seem to be copying and backin up. Please correct this impression if I misunderstand.

Assuming these files are not compressed, a backup tool that does compression might serve your purpose better. It may allow you to back up more of that data, perhaps all of it depending upon the compression ratio you achieve.

The nature of the storage is also unclear. If that 8T is on a remote server, you might prioritize your structure and pull data from the remote end until some storage saturation level is reached that you can accept (90%?). If that 8T is running under a mature OS, perhaps it can be mounted with compression and you can do simple copy operations (scp perhaps).

Rsync is wonderful for keeping two file systems in sync, but for doing the initial copy it is less than optimal.
More detail on the nature of the storage (at both ends) and the nature of the files might lead to more targeted and appropriate advice.
I hope that this helps.