I'm trying to decide whether to go for FreeNAS self build, unraid self build or buy a synology. I have a lot of randomly sized hard drives. My data is very important to me, so I want at least 2 parity drives. I found a calculator for Synology, which tells me it'll give me 18.5tb of space with 2 parity drives under RAID array type "SH2". It also shows standard RAID 6 (with 2 parity drives) would only provide 4.5TB of space. Is there any similar raid type to SH2 with unraid?
My spare hard drives (in TB): 2, 2, 3, 3, 2, 4, 0.5, 6, 2, 6, 1
Synology SH2 & RAID space calculator for random hard drive sizes:
https://www.synology.com/en-uk/support/RAID_calculator?hdds=2 TB|2 TB|3 TB|3 TB|2 TB|6 TB|2 TB|6 TB|500 GB|1 TB|4 TB
Also, is there a similar calculator for UNRAID with its supported raid types? The only one I could find was an old out-dated unraid calculator that was made in 2009 (!) by an unraid user and doesn't allow you to select the number of parity drives or raid type like the synology calculator.
Old unraid calculator from 2009, probably out of date: http://unraid.category5.tv/
Would appreciate thoughts on this.
Thanks in advance