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From: Roman Mamedov <rm@romanrm.ru>
To: Suman C <schakrava@gmail.com>
Cc: "Fajar A. Nugraha" <list@fajar.net>,
	Mike Fleetwood <mike.fleetwood@googlemail.com>,
	linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: lvm volume like support
Date: Tue, 26 Feb 2013 11:57:04 +0600	[thread overview]
Message-ID: <20130226115704.50102196@natsu> (raw)
In-Reply-To: <CAPF83mvfLrDvBvbP5Oe_R94BM7Lr5pZD=gpnDrr4TquBq88q5Q@mail.gmail.com>

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On Mon, 25 Feb 2013 21:35:08 -0800
Suman C <schakrava@gmail.com> wrote:

> Yes, zvol like feature where a btrfs subvolume like construct can be
> made available as a LUN/block device. This device can then be used by
> any application that wants a raw block device. iscsi is another
> obvious usecase. Having thin provisioning support would make it pretty
> awesome.

I think what you are missing is that btrfs is a filesystem, not a block device
management mechanism.

For your use case can simply create a snapshot and then make a sparse file
inside of it.

  btrfs sub create foobar
  dd if=/dev/zero of=foobar/100GB.img bs=1 count=1 seek=100G

If you need this to be a block device, use 'losetup' to make foobar/100GB.img
appear as one (/dev/loopX). But iSCSI/AoE/NBD can export files as well as block
devices, so this is not even necessary.

-- 
With respect,
Roman

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  parent reply	other threads:[~2013-02-26  5:57 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-25 23:35 lvm volume like support Suman C
2013-02-26  0:59 ` Mike Fleetwood
2013-02-26  1:46   ` Fajar A. Nugraha
2013-02-26  5:35     ` Suman C
2013-02-26  5:48       ` Remco Hosman - Yerf-IT
2013-02-26  5:57       ` Roman Mamedov [this message]
2013-02-26  6:25         ` Suman C
2013-02-26  6:28           ` Remco Hosman - Yerf IT
2013-02-26  6:37             ` Alex Elsayed
2013-02-26  7:08             ` Dave Chinner
2013-04-19 18:13           ` Andy Grover
2013-02-26 10:30     ` Martin Steigerwald
2013-02-27  2:23       ` Fajar A. Nugraha
2013-02-27  4:05         ` Roman Mamedov
2013-02-27  8:42           ` Martin Steigerwald
2013-02-27  9:17             ` Roman Mamedov
2013-02-27  8:50           ` Alex Elsayed
2013-02-27  9:57             ` Alex Elsayed
2013-02-27 10:12               ` Alex Elsayed
2013-04-08 12:01                 ` David Sterba
2013-04-11 12:29                   ` David Sterba
2013-03-02  6:24               ` Marcus Sorensen

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