SnapRAID - Parity - Split Parity

Split the parity across multiple partitions.

Multiple files can be specified for a single parity.
As soon a file cannot grow anymore, the next one starts growing.

In the configuration file, just put more files in the same 'parity' line, separated by , (comma).

The parity disk needs to be as large or larger than the data disks.

NOTE: Historically, adding larger data disks to the array always required to similarly needing to also increase the parity disk to be as large or larger than the largest data disk.

This would mean needing to potentially acquire an additional large disk to ensure the parity was also as larger as this new data disk.
More cost…

Assuming the array is made up of (4) 4TB data disks and (1) 4TB parity disk.

If a new 8TB data disk was added to the array, then the current 4TB parity disk would not be large enough.
This would require to also having to replace the parity disk with a similar 8TB disk.

With split parity, there is no need to replace the parity disk with a new larger disk.

Instead, some smaller disks can be joined together as one complete set of parity.

For example, as there is a new 8TB data, this means that there should also be at least 8TB of parity.

(2) 4TB disks could be used, joined together as one complete set of parity; or
(4) 2TB disks, could be similarly joined.

Example

/etc/snapraid.conf

parity /mnt/split-parity/parity1-disk1/part1.parity,/mnt/split-parity/parity1-disk2/part2.parity
2-parity /mnt/split-parity/parity2-disk1/part1.parity,/mnt/split-parity/parity2-disk2/part2.parity

Split Parity