[CentOS] OT: Replacing Venerable NAS

I have an original-label Infrant (now NetGear) ReadyNAS storage appliance that's been running for 8+ years. Except for replacing its power supply, it has not skipped a beat in all this time.

I use it primarily as a backup device (via NFS) for a couple of Linux machines, (via SMB) for a couple of Windows PC's, and (via ftp) for web sites at my hosting provider.

SMART+ reporting shows ~75K hours operation, with zero sectors reallocated, on each of the four disks.

I'm thinking I should be looking for a replacement, even with all this good info/luck.

Would like to hear recommendations here. Besides the ReadyNAS, I have worked with a Thecus NAS (don't recall model). What are the features I should look at?

Thanks.