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From: Tomasz Chmielewski <mangoo@wpkg.org>
To: Chris Mason <chris.mason@oracle.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: LVM vs btrfs as a "volume manager" for SANs
Date: Thu, 02 Jul 2009 17:22:24 +0200	[thread overview]
Message-ID: <4A4CD0B0.2080907@wpkg.org> (raw)
In-Reply-To: <1240576718.29896.2.camel@think.oraclecorp.com>

Chris Mason wrote:
> On Fri, 2009-04-24 at 01:34 +0200, Tomasz Chmielewski wrote:
>> Chris Mason schrieb:
>>
>>>> However, with btrfs, I'm not sure about:
>>>>
>>>> - what happens if SAN machine crashes while the iSCSI file images were 
>>>> being written to; with LVM and its block devices, I'm somehow more 
>>>> confident it wouldn't make more data loss than necessary
>>> If iscsi is writing with O_DIRECT|O_SYNC it should work.
>> What if it doesn't?
>>
> 
> Writes would go to the page cache only (not O_DIRECT) and the metadata
> wouldn't get flushed with each write (not O_SYNC).

What about the "administrative" part of using btrfs as a volume manager?

For example, I can partition (fdisk + kpartx), extend volumes in LVM 
easily, on the host.


Are there any tools to "partition" or "extend" file images?

qemu-nbd and nbd-client come to mind, but it's a bit of an overhead (in 
typing, I mean).


-- 
Tomasz Chmielewski
http://wpkg.org



  reply	other threads:[~2009-07-02 15:22 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-22 19:20 LVM vs btrfs as a "volume manager" for SANs Tomasz Chmielewski
2009-04-23  0:13 ` Dmitri Nikulin
2009-04-23 18:45 ` Chris Mason
2009-04-23 23:34   ` Tomasz Chmielewski
2009-04-24 12:38     ` Chris Mason
2009-07-02 15:22       ` Tomasz Chmielewski [this message]
2009-07-06 18:51         ` Chris Mason

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