From: waxhead <waxhead@dirtcellar.net>
To: Anand Jain <anand.jain@oracle.com>,
Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Subject: Re: BTRFS subvolume RAID level
Date: Tue, 3 Dec 2019 00:27:47 +0100 [thread overview]
Message-ID: <fcbe2d91-a6ad-5b9b-fa66-aebb2edd14f1@dirtcellar.net> (raw)
In-Reply-To: <ed65c577-3971-8c4f-c690-83e85dd8188e@oracle.com>
Anand Jain wrote:
>
>> I imagine that RAIDc4 for example could potentially give a grotesque
>> speed increase for parallel read operations once BTRFS learns to
>> distribute reads to the device with the least waitqueue / fastest
>> devices.
>
> That exactly was the objective of the Readmirror patch in the ML.
> It proposed a framework to change the readmirror policy as needed.
>
> Thanks, Anand
Indeed. If I remember correctly your patch allowed for deterministic
reading from certain devices. As just a regular btrfs user the problem I
see with this is that you loose a "potential free scrub" that *might*
otherwise happen from often read data. On the other hand that is what
manual scrubbing is for anyway.
next prev parent reply other threads:[~2019-12-02 23:27 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-28 22:48 BTRFS subvolume RAID level waxhead
2019-11-29 0:44 ` Qu Wenruo
2019-12-02 10:48 ` Anand Jain
2019-12-02 23:27 ` waxhead [this message]
2019-12-03 1:30 ` Anand Jain
2019-12-03 20:31 ` waxhead
2019-12-05 12:10 ` Anand Jain
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