qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] QCow v2


From: Johannes Schindelin
Subject: Re: [Qemu-devel] QCow v2
Date: Tue, 4 Jul 2006 15:28:29 +0200 (CEST)

Hi,

On Tue, 4 Jul 2006, Christian MICHON wrote:

> ok, I used "split -b 4k" on a 7716864 bytes qcow.
> I used standard lzma compression and get 1884 7z-clusters
> with a grand total of 3558617 bytes (indeed the gain is small).
> 
> The standard zlib qcow gave 3704180 bytes...

That is what I expected.

> Does it make sense to have a cluster based compression ?
> Indeed the actual compression is not so impressive then (zlib
> or not zlib based).

Absolutely! Remember, you want to emulate a _random_ access device here. 
And it is no good if you need 10 minutes just to access the last cluster 
of the emulated hard drive, especially if this is the only one you are 
interested in.

Hth,
Dscho





reply via email to

[Prev in Thread] Current Thread [Next in Thread]