Given the comments regarding the cost of true hardware RAID in some of my searches like here or here, it would appear that $500 solutions like Synology DS413, Netgear ReadyNAS Ultra 4, QNAP TS-419P must use software-based RAID. True? Are they using a hybrid hardware-software combo?
All manufacturers appear to offer some proprietary version of expandable RAID (Netgear X-RAID, Synology Hybrid RAID, etc). I believe these boxes run Linux inside, are these proven Linux software RAID algorithms that the manufacturers are branding, or truly proprietary? Any less reliable than tried-and-true RAID-1, 5, 10, etc?
I would just like to understand the internals of these machines a little better before trusting them with terabytes of important data. Thanks.
There’s no point in re-inventing the wheel. I know that Synology and QNAP use
mdadm (all bets are off with Netgear hardware). It’s a tried and true solution, and in a NAS a huge cost saving and performance is OK. Given that new file systems like ZFS basically make hardware-level raid redundant, this is an OK thing.
The only time when it’s not so great is for high throughput on heavy protocols like iSCSI. Then the challengine of pushing all that data, the iSCSI protocol and the RAIDing system will run the system to 100% CPU and 100% RAM easily.