Re: {* 05.00 *}Re: Desperate with 870 QVO and ZFS

Stefan Esser <[email protected]> Thu, 7 Apr 2022 12:05:42 +0200
Newsgroups gmane.os.freebsd.devel.hackers,gmane.os.freebsd.devel.file-systems,gmane.os.freebsd.performance
Message-ID <[email protected]>
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From: Stefan Esser <[email protected]>
To: [email protected]
Cc: [email protected], [email protected],
 [email protected], Rainer Duffner <[email protected]>
Message-ID: <[email protected]>
Subject: Re: {* 05.00 *}Re: Desperate with 870 QVO and ZFS
References: <[email protected]>
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In-Reply-To: <[email protected]>

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Am 06.04.22 um 23:49 schrieb Stefan Esser:
> Am 06.04.22 um 18:34 schrieb [email protected]:
>=20
>>> The 870 QVO is specified for 370 full capacity
>>> writes, i.e. 370 TB for the 1 TB model. That's still a few hundred
>>> GB a day - but only if the write amplification stays in a reasonable
>>> range ...
>>> =C2=A0
>>> *Well yes... 2880TB in our case....not bad.. isn't it?*
>=20
> I assume that 2880 TB is your total storage capacity? That's not too ba=
d, in
> fact. ;-)

I just noticed that this is not the extreme total size of a ZFS pool
(should have noticed this while answering late at night ...)

And no, a specified life-time of 2880 TB written is not much, it is
at the absolute lower end of currently available SSDs at 360 TB per
1 TB of capacity.

This is equivalent to 360 total capacity writes, but given the high
amount of write amplification that can be assumed to occur in your
use case, I'd heavily over-provision a system with such SSDs ...
(or rather: strictly avoid them in a non-consumer setting).

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