Compatability of Seagate 4TB USB 3.0 External Drive?

Connect the disk up to a PC and see if you can use the SeaGate utility for the disk to disable the sleep timer.

^ Thanks.

I think I have made progress. Hours of effort unfortunately...

If you format your external USB drive using ext2/3 format the Seagate tools (both Mac and Windows versions) WILL NOT recognize the drive. There seem to be methods to disable sleep, but many seem to be tied to the computer and a particular USB port rather than the drive itself. I reformatted the drive using FAT format, then used the Seagate tools (GoFlex Bundled Software, which includes SeaTools) to change the sleep to never. Finally used the NAS to reformat back to ext2/3. Now I am testing to see if it will stay connected for at least 24 hours. Looks promising so far.

All sorted out. External HD now cooperating and not going offline so backups are working. Thanks mdgm!

Ugh. One step forward and one back. My scheduled backups now run with about 50% repeatability due to the external USB hard disk periodically going off line. The email message reports that the backup was aborted because the destination is not connected. Powering down the drive and powering back up seems to work for some small number of backups. I realize this is now more of a Seagate issue than a Readynas issue. I expect better advise here than from Seagate though... Thanks again.