Recommendations for Backup NAS

[Enquiries]

NAS for Backup

Need to backup Synology 1621xs+ to second nas,

1621xs+ running with 4 16TB hdd. May add 2 more hdd some point in the future but not soon.

Currenlty have 20TB data with 26TB free.

Prefer backup nas to be synology probably a plus (+) model . Debating if I need 4 bay or 5 bay. Looking at DS423+, 923+, 1522+, or 1621+.

I have 4 Western Digial Red HDDs i could put in them. 1-!4TB, 2-8TB, and 1-6TB i can use in the backup nas.

All my computers are Macs.

[ed]

Good setup with the 1621xs+! For a backup NAS, staying with Synology makes sense, and with your budget ($600-$900), here’s how the models stack up:

DS423+ – Affordable 4-bay option, but lacks ECC memory. If backups are the only use case, it could work, but it’s a bit underpowered compared to your main NAS.
DS923+ – More powerful than the DS423+, supports NVMe storage pools, but still no ECC RAM.
DS1522+ – Solid balance of performance and expandability. Having a 5th bay gives you flexibility for future storage growth. Also has ECC memory, which is great for reliability.
DS1621+ – Best match for your main NAS. ECC RAM, great long-term investment, and more storage flexibility. If you want to mirror your 1621xs+ more closely, this is the ideal pick.
Since you already have WD Red drives (14TB, 8TB x2, 6TB), a 5-bay NAS (DS1522+) might be a better fit to make use of them effectively without feeling limited later. If you can stretch the budget a bit, the DS1621+ is the most future-proof option.