Hi, is there a way to maintain an IO cache on dom0 for all domU ? I have near 1Go not used ram on a Dom0, and would like to use this memory to speedup all the domU. All my domU use LVM phy devices. Thanks, Olivier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Mon, Sep 7, 2009 at 11:13 PM, Olivier B.<xen.list@daevel.fr> wrote:> Hi, > > is there a way to maintain an IO cache on dom0 for all domU ?Generally not recommended as it could cause data corruption on domU side. If you REALLY want to use it anyway despite the consequences, AFAIK file:/ does that by default, and it should work even for block devices.> > I have near 1Go not used ram on a Dom0, and would like to use this memory to > speedup all the domU. All my domU use LVM phy devices.1G is not much :P. IMHO you better add it to the busiest domU. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, thanks, it can be a solution (from http://oss.oracle.com/pipermail/tmem-devel/2009-January/000002.html ), but not sure if it''s "automatic" in recent kernels. I''ll search that. Thanks. Olivier Hui Kang wrote:> Hi, > I am not sure if the pre-cache feature provided by tmem would meet you > need. > > - Hui > > Olivier B. wrote: >> Hi, >> >> is there a way to maintain an IO cache on dom0 for all domU ? >> >> I have near 1Go not used ram on a Dom0, and would like to use this >> memory to speedup all the domU. All my domU use LVM phy devices. >> >> Thanks, >> Olivier >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users >> >> . >> >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha wrote:> On Mon, Sep 7, 2009 at 11:13 PM, Olivier B.<xen.list@daevel.fr> wrote: > >> Hi, >> >> is there a way to maintain an IO cache on dom0 for all domU ? >> > > Generally not recommended as it could cause data corruption on domU side. > If you REALLY want to use it anyway despite the consequences, AFAIK > file:/ does that by default, and it should work even for block > devices. >Well if you only do read caching, what problem can you have ? And for write caching, the problem is the same as for write cache on RAID cards, so barriers should already avoid problems with that, no ? I will look at your suggestion, thanks.>> I have near 1Go not used ram on a Dom0, and would like to use this memory to >> speedup all the domU. All my domU use LVM phy devices. >> > > 1G is not much :P. IMHO you better add it to the busiest domU.Well to simulate a "raid hard card", it''s enough I think ;) Olivier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users