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* [Qemu-devel] Question about IDE TRIM Command
@ 2012-02-02 11:55 kazushi takahashi
  0 siblings, 0 replies; 2+ messages in thread
From: kazushi takahashi @ 2012-02-02 11:55 UTC (permalink / raw)
  To: qemu-devel

Hi all

I have a question about IDE TRIM Command.

As you know, QEMU have supported TRIM command since QEMU 0.15.0.

Some QEMU disk images such as qcow2 support bdrv_discard function
which will be called when guest OS executes ATA TRIM command.

So, I think qcow2 image has a function to delete the disk pages which are
recognized as discarded by guest OS.

I think that to enable TRIM Command, we have to emulate guest HDD as
Solid State Drive. However, it seems QEMU does not emulate guest
HDD as Solid State Drive. Thus, I think that bdrv_discard functions in
qemu images are never called by guest OS.

Is my thinking correct?

Thanks,
Kazushi Takahashi

^ permalink raw reply	[flat|nested] 2+ messages in thread
* [Qemu-devel] Question about IDE TRIM Command
@ 2012-02-02 13:20 kazushi takahashi
  0 siblings, 0 replies; 2+ messages in thread
From: kazushi takahashi @ 2012-02-02 13:20 UTC (permalink / raw)
  To: qemu-devel

Hi all

I have a question about IDE TRIM Command.

As you know, QEMU have supported TRIM command since QEMU 0.15.0.

Some QEMU disk images such as qcow2 support bdrv_discard function
which will be called when guest OS executes ATA TRIM command.

So, I think qcow2 image has a function to delete the disk pages which are
recognized as discarded by guest OS.

I think that to enable TRIM Command, we have to emulate guest HDD as
Solid State Drive. However, it seems QEMU does not emulate guest
HDD as Solid State Drive. Thus, I think that bdrv_discard functions in
qemu images are never called by guest OS.

Is my thinking correct?

Thanks,
Kazushi Takahashi

^ permalink raw reply	[flat|nested] 2+ messages in thread
end of thread, other threads:[~2012-02-02 13:20 UTC | newest]

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