[ovirt-devel] VDSM changes Linux memory dirty ratios - why?

Sven Kieske s.kieske at mittwald.de
Wed Nov 30 12:10:31 UTC 2016


On 30/11/16 08:48, Martin Polednik wrote:
> It's not really irrelevant, the host still uses disk cache. Anyway,
> there is BZ[1] with a presentation[2] that (imho reasonably) states:
> 
> "Reduce dirty page limits in KVM host to allow
> direct I/O writer VMs to compete successfully
> with buffered writer processes for storage
> access"
> 
> I wonder why virtual-host tuned profile doesn't contain these values:
> 
> $ grep vm.dirty /usr/lib/tuned/virtual-host/tuned.conf
> vm.dirty_background_ratio = 5
> 
> [1]https://bugzilla.redhat.com/show_bug.cgi?id=740887
> [2]http://perf1.lab.bos.redhat.com/bengland/laptop/rhev/rhev-vm-rsptime.pdf

Could you share [2] with the wider community? This would be awesome!
-- 
Mit freundlichen Grüßen / Regards

Sven Kieske

Systemadministrator
Mittwald CM Service GmbH & Co. KG
Königsberger Straße 6
32339 Espelkamp
T: +495772 293100
F: +495772 293333
https://www.mittwald.de
Geschäftsführer: Robert Meyer
St.Nr.: 331/5721/1033, USt-IdNr.: DE814773217, HRA 6640, AG Bad Oeynhausen
Komplementärin: Robert Meyer Verwaltungs GmbH, HRB 13260, AG Bad Oeynhausen

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: OpenPGP digital signature
URL: <http://lists.ovirt.org/pipermail/devel/attachments/20161130/a719bb80/attachment-0001.sig>


More information about the Devel mailing list