ReadyNAS Duo drops off LAN

My condolences on joining the lost data club. I joined decades ago. Now you know why we beat the drum about maintaining a current and complete backup and to never ever trust your data to a single device, be it a single hard drive or an NAS. I would recommend that you get not one, but two external drives. When you back up to the first it is father. When you back up to the second a period of time later, that becomes father and the first one is grandfather. The period of time depends on how often your data changes.

Even though I have two NAS units, one backing up the other via rsync, I still have two WD passports which I use to maintain a backups of my critical financial and personal data. Father is always stored in my SD box at the bank, just in case of a disaster at my home. I used to use my desk at work until I retired. Before I got my second NAS, I updated my backup weekly, but now I only update the USB drive on a monthly basis.

But you must decide on your own schedule and how many USB drives you need to maintain a comfort level. BTW, my backups on the WD drive are FAT32, so I can read them on a Windows PC, they are my disaster recovery plan after all.