80% Rule for larger Zpools

Hello,

is the rule of filling a Zpool to max. around 80% still valid, nowadays?
If I think about a larger pool of around 20 TB size, this would mean that 4 TB cannot be used. Is it fine with larger pools to fill them up to a higher percentage?
Is there a percentage value which is a “best practice” for larger pools?

Thanks a lot in advance,

Thomas

The real rule is that you shouldn’t fill it past 95%, where allocation modes change (or is it 90%… perhaps things do change)

Anyway, at 80% start planning an upgrade, and aim to finish before you get to 90%

And yes, all the performance reasons justifying that still apply.

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