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Date: Mon, 27 Apr 2015 10:06:22 +0200
From: Richard Weinberger <richard@nod.at>
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To: Dolev Raviv <draviv@codeaurora.org>
Subject: Re: planning general storage capacity for y fs
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Am 27.04.2015 um 09:55 schrieb Dolev Raviv:
> Thanks Richard!
> Let me rephrase the question: In the past I knew there was a rule of thumb, 'leave free 30% of the storage space'. Nowadays I couldn't find any reference to this.

Most likely because this is and was always kind of superstition. ;)
An almost full filesystems has to do more to find free space, but I don't dare to
give rules of thumb.

> I was wondering, is there a known point in UBIFS (or ext4), where leaving less free storage space, that performance is dropping? Maybe a ratio of free-occupied is not the right way to look at it, but to leave a certain size free (e.g. 50MB)?

I don't think so. Maybe Ted can give you more details on ext4.
For UBIFS I'd say, figure yourself. i.e. run benchmarks...

Thanks,
//richard