[fnord123]

More is not better. Repair time gets slower as the ratio for transport speed to capacity gets lower and lower. This means that more file pieces can be lost during the longer repair window resulting in possible data loss.

Keep in mind that when people calculate lifetimes and repairs they usually assume that drive failures are independent. Given that they are installed at the same time and usually from the same manufacturer and bought at the same time (e.g. same batch), it's not great to assume that all these things are independent.

[jnwatson]

In my 50 TB RAID 5, it has never finished a monthly scheduled raid sync because it takes roughly a week to complete, and performance during the sync is so bad that it is unusable.

[manquer]

You can always buy lower capacity drives and plug more in.