From: Paolo Bonzini <pbonzini@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Kevin Wolf <kwolf@redhat.com>,
qemu-devel@nongnu.org,
Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Subject: Re: [Qemu-devel] [PATCH 00/17] Support mismatched host and guest logical block sizes
Date: Wed, 21 Dec 2011 18:00:03 +0100 [thread overview]
Message-ID: <4EF21093.6030408@redhat.com> (raw)
In-Reply-To: <20111221165528.GA27101@lst.de>
On 12/21/2011 05:55 PM, Christoph Hellwig wrote:
> On Wed, Dec 14, 2011 at 01:40:22PM +0100, Paolo Bonzini wrote:
>> If the partitions are aligned, the OS will always issue aligned requests,
>> because file system blocks are already 4k.
>
> It won't nessecarily. For example XFS will do a fair amount of sub-blocksize
> I/O for metadata and the log. Note that if you tell XFS that the
> minimal_io_size is 4k it will at least align the log write to it, which
> is what really matters.
The physical_block_size doesn't matter?
Paolo
prev parent reply other threads:[~2011-12-21 17:00 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-13 12:37 [Qemu-devel] [PATCH 00/17] Support mismatched host and guest logical block sizes Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 01/17] block: do not rely on open_flags for bdrv_is_snapshot Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 02/17] block: store actual flags in bs->open_flags Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 03/17] block: pass protocol flags up to the format Paolo Bonzini
2011-12-15 4:10 ` Zhi Yong Wu
2011-12-13 12:37 ` [Qemu-devel] [PATCH 04/17] block: non-raw protocols never cache Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 05/17] block: remove enable_write_cache Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 06/17] block: move flag bits together Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 07/17] raw: remove the aligned_buf Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 08/17] block: rename buffer_alignment to guest_block_size Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 09/17] block: add host_block_size Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 10/17] raw: probe host_block_size Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 11/17] iscsi: save host block size Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 12/17] block: allow waiting only for overlapping writes Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 13/17] block: allow waiting at arbitrary granularity Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 14/17] block: protect against "torn reads" for guest_block_size > host_block_size Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 15/17] block: align and serialize I/O when guest_block_size < host_block_size Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 16/17] block: default physical block size to host block size Paolo Bonzini
2011-12-13 12:37 ` [Qemu-devel] [PATCH 17/17] qemu-io: add blocksize argument to open Paolo Bonzini
2011-12-14 11:13 ` [Qemu-devel] [PATCH 00/17] Support mismatched host and guest logical block sizes Kevin Wolf
2011-12-14 11:47 ` Paolo Bonzini
2011-12-14 12:05 ` Kevin Wolf
2011-12-14 12:40 ` Paolo Bonzini
2011-12-21 16:55 ` Christoph Hellwig
2011-12-21 17:00 ` Paolo Bonzini [this message]
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