Alberto García

O Grove (Spain), 1978

One of the founding members of Igalia, Alberto loves computing since he got his first ZX Spectrum in the early nineties.

Latest Updates

Alberto García 08/02/2017

QEMU and the qcow2 metadata checks

When choosing a disk image format for your virtual machine one of the factors to take into considerations is its I/O performance. In this post I’ll talk a bit about the internals of qcow2 and about one of the aspects that can affect its performance...

Alberto García 24/05/2016

I/O bursts with QEMU 2.6

QEMU 2.6 was released a few days ago. One new feature that I have been working on is the new way to configure I/O limits in disk drives to allow bursts and increase the responsiveness of the virtual machine. In this post I’ll try to explain how it...

Alberto García 17/12/2015

Improving disk I/O performance in QEMU 2.5 with the qcow2 L2 cache

QEMU 2.5 has just been released, with a lot of new features. As with the previous release, we have also created a video changelog. I plan to write a few blog posts explaining some of the things I have been working on. In this one I’m going to talk...


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hmp: Make block_stream set an explicit job ID

hmp: Make block_stream set an explicit job ID A job ID is always required in order to create a block job on a non-root node. The default ID (obtained with bdrv_get_device_name()) is otherwise empty in this scenario and the job cannot be created. The...

Alberto García19/01/2017

qemu-iotests: Test the 'base-node' parameter of 'block-stream'

qemu-iotests: Test the 'base-node' parameter of 'block-stream' The block-stream command has traditionally used the 'base' parameter to indicate the image to copy the data from. This test checks that the 'base-node'...

Alberto García19/01/2017

block: Add 'base-node' parameter to the 'block-stream' command

block: Add 'base-node' parameter to the 'block-stream' command The way to specify the node from which to copy data in the block-stream operation is by using the 'base' parameter. This parameter however takes a file name, not a...

Alberto García19/01/2017

qemu-iotests: Test streaming to a Quorum child

qemu-iotests: Test streaming to a Quorum child Quorum children are special in the sense that they're not directly attached to a block backend but they're not used as backing images either. However the intermediate block streaming code...

Alberto García19/01/2017

qemu-iotests: Add iotests.supports_quorum()

qemu-iotests: Add iotests.supports_quorum() There's many tests that need Quorum support in order to run. At the moment each test implements its own check to see if Quorum is enabled. This patch centralizes all those checks in a new function called...

Alberto García19/01/2017