From: Christoph Hellwig <hch@infradead.org>
To: Valerie Aurora Henson <vaurora@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>,
Ray Van Dolson <rayvd@bludgeon.org>,
linux-btrfs@vger.kernel.org
Subject: Re: Data-deduplication?
Date: Fri, 17 Oct 2008 16:10:46 -0400 [thread overview]
Message-ID: <20081017201046.GA20862@infradead.org> (raw)
In-Reply-To: <20081016192501.GE16946@shell>
On Thu, Oct 16, 2008 at 03:25:01PM -0400, Valerie Aurora Henson wrote:
> Both deduplication and compression have an interesting side effect in
> which a write to a previously "allocated" block can return ENOSPC.
> This is even more exciting when you factor in mmap. Any thoughts on
> how to handle this?
Note that this can already happen in todays filesystems. Writing into
some preallocated space can always cause splits of the allocation or
bmap btrees as the pervious big preallocated extent now is split into
one allocated and at least one (or two if writing into the middle)
preallocated extents.
prev parent reply other threads:[~2008-10-17 20:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-12 2:06 Data-deduplication? Ray Van Dolson
2008-10-13 8:52 ` Data-deduplication? Andi Kleen
2008-10-15 13:39 ` Data-deduplication? Avi Kivity
2008-10-15 14:15 ` Data-deduplication? Andi Kleen
2008-10-15 14:43 ` Data-deduplication? Miguel Sousa Filipe
2008-10-15 15:00 ` Data-deduplication? Andi Kleen
2008-10-15 17:49 ` Data-deduplication? Avi Kivity
2008-10-13 11:02 ` Data-deduplication? Chris Mason
2008-10-16 19:25 ` Data-deduplication? Valerie Aurora Henson
2008-10-16 19:30 ` Data-deduplication? Chris Mason
2008-10-17 18:24 ` Data-deduplication? Valerie Aurora Henson
2008-10-20 0:16 ` Data-deduplication? Chris Mason
2008-10-21 20:33 ` Data-deduplication? Valerie Aurora Henson
2008-10-17 20:10 ` Christoph Hellwig [this message]
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