From: Johannes Thumshirn <Johannes.Thumshirn@wdc.com>
To: "dsterba@suse.cz" <dsterba@suse.cz>
Cc: David Sterba <dsterba@suse.com>,
"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>,
Damien Le Moal <Damien.LeMoal@wdc.com>
Subject: Re: [PATCH] btrfs-progs: default to SINGLE profile on zoned devices
Date: Mon, 12 Jul 2021 19:16:36 +0000 [thread overview]
Message-ID: <PH0PR04MB74163E89A308E4A7760B41119B159@PH0PR04MB7416.namprd04.prod.outlook.com> (raw)
In-Reply-To: PH0PR04MB74164EDF2921DB4141CD40579B1A9@PH0PR04MB7416.namprd04.prod.outlook.com
On 07/07/2021 17:02, Johannes Thumshirn wrote:
> On 07/07/2021 16:53, David Sterba wrote:
>> On Tue, Jul 06, 2021 at 06:19:22PM +0900, Johannes Thumshirn wrote:
>>> On zoned devices we're currently not supporting any other block group
>>> profile than the SINGLE profile, so pick it as default value otherwise a
>>> user would have to specify it manually at mkfs time for rotational zoned
>>> devices.
>>
>> Yes this is annoying but careful with setting defaults, it's hard to
>> change them. And in case of zoned devices it will be possible to set
>> something else in the future so defaulting to single/single needs to be
>> justified in another way than "currently we don't support anything
>> else".
>>
>> The SSD fallback to single is not showing as useful and there's ongoing
>> work to make it default to dup for metadata again. For consistency I'd
>> rather have simple logic for selecting defaults and give hints
>> eventually instead of checking random things in the system and then
>> selectin on behalf of the user. Unfortunatelly it's not that easy as
>> there are conflicting valid interests and we don't have defaults that
>> fits all scenarios.
>>
>
> Agreed, but without this patch mkfs with default parameters on a rotational
> zoned device will fail with:
>
> johannes@redsun60:btrfs-progs(master)$ sudo ./mkfs.btrfs /dev/sda
> btrfs-progs v5.12.1
> See http://btrfs.wiki.kernel.org for more information.
>
> Zoned: /dev/sda: host-managed device detected, setting zoned feature
> ERROR: cannot use RAID/DUP profile in zoned mode
>
> So defaulting to not creating a filesystem won't work either.
>
> We could improve the error message hinting the user to specify
> "-m single -d single" on mkfs but that feels more hacky than setting
> the defaults to something working.
>
So what's the way to go here? The current default won't create a file
system so it's unusable.
next prev parent reply other threads:[~2021-07-12 19:16 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-06 9:19 [PATCH] btrfs-progs: default to SINGLE profile on zoned devices Johannes Thumshirn
2021-07-06 13:41 ` Nikolay Borisov
2021-07-07 14:50 ` David Sterba
2021-07-07 15:01 ` Johannes Thumshirn
2021-07-12 19:16 ` Johannes Thumshirn [this message]
2021-07-30 14:09 ` David Sterba
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