Jürgen Keil wrote: > Is it true (it seems so...) that the linux dom0 pv block backend driver > is bypassing the buffer / page cache of dom0 [*]? > And the solaris dom0 block backend driver doesn't? > > Are there any technical reasons why linux doesn't cache in dom0? > > Is it a bug or feature that solaris does cache in dom0? > > Well, a positive effect of solaris dom0 cacheing seems to be > that /boot/solaris/bin/create_ramdisk inside a solaris domU is > much faster when running on a solaris dom0 than on a linux dom0. > E.g. (8G - 1G) dom0 ubuntu amd64 + 1G solaris amd64 PV domU > needs ~40 seconds for create_ramdisk in domU, while > (4G - 0.5G) dom0 solaris amd64 + .5G solaris amd64 PV domU > needs ~22 seconds for create_ramdisk in domU. > > > [*] http://lists.xensource.com/archives/html/xen-devel/2005-05/msg01167.html >
Heres's Stu's answer... "the Solaris backend caches deliberately since we are emulating a disk with a write buffer, and we support the flush cache operation to ensure that front end software has a way to guarantee that written data is on stable storage. In the same way that issuing a flush to a disk with a write cache will. " MRJ _______________________________________________ xen-discuss mailing list [email protected]
