From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53162) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ynrv5-0000t5-64 for qemu-devel@nongnu.org; Thu, 30 Apr 2015 13:06:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ynrnj-000226-UW for qemu-devel@nongnu.org; Thu, 30 Apr 2015 12:59:07 -0400 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:53370) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ynrnj-00020q-AA for qemu-devel@nongnu.org; Thu, 30 Apr 2015 12:59:03 -0400 Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 30 Apr 2015 22:28:57 +0530 From: Nikunj A Dadhania In-Reply-To: References: <1430204006-10160-1-git-send-email-nikunj@linux.vnet.ibm.com> <1430204006-10160-2-git-send-email-nikunj@linux.vnet.ibm.com> <20150428133029.3494542e@thh440s> <20150429015638.GC32589@voom.redhat.com> <87sibjxsfo.fsf@abhimanyu.in.ibm.com> <5540975F.3090804@redhat.com> <87pp6nxq0x.fsf@abhimanyu.in.ibm.com> <5540A00D.4080500@redhat.com> <87twvy5it1.fsf@linux.vnet.ibm.com> <5541F34D.3070603@suse.de> <20150430114041.412238a2@thh440s> Date: Thu, 30 Apr 2015 22:28:51 +0530 Message-ID: <87h9rxk0xg.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [REBASE PATCH v5 1/2] machine: add default_ram_size to machine class List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf , Thomas Huth Cc: "aik@ozlabs.ru" , "qemu-devel@nongnu.org" , "armbru@redhat.com" , "qemu-ppc@nongnu.org" , "marcel.apfelbaum@gmail.com" , "imammedo@redhat.com" , Paolo Bonzini , David Gibson Alexander Graf writes: >> Am 30.04.2015 um 11:40 schrieb Thomas Huth : >> On Thu, 30 Apr 2015 11:18:05 +0200 >> Alexander Graf wrote: >>>> On 30.04.15 06:41, Nikunj A Dadhania wrote: >>>> >>>> Hi Paolo, >>>> >>>> Paolo Bonzini writes: >>>>> On 29/04/2015 11:06, Nikunj A Dadhania wrote: >>>>>>> so David can push both patches. >>>>>>> >>>>>>> But isn't 1G a bit too much? At least on x86 you can easily boot with 512M. >>>>>> >>>>>> I understood this number as not the _minimum memory_ to boot the >>>>>> VM. And this will only come in picture when the user has not specified >>>>>> any memory. >>>>> >>>>> This in turn will basically only happen for QEMU developers. So keeping >>>>> the default on the low side would make sense. >>>>> >>>>> On my (4G memory) laptop I might not even be able to boot a PPC64 VM >>>>> with 1G and TCG, but I can do that nicely with 256M. >>>> >>>> That will be fine with me as well, i.e. 256M >>>> >>>> David/Alex, Do you have comments on this before we change it? >>> >>> I've seen RAM size combinations that seemed to work ok, but then failed >>> during grub2 execution for example. Please verify with all reasonably >>> realistically executed distributions that 256MB is enough. >> >> Since this default value will likely be there for the next couple of >> years, it's maybe better to use a slightly higher value than one that >> is too low - the amount of RAM that a guest requires likely rather >> increases in the next years instead of going down again. So I think >> using 512 MB instead is maybe a good compromise? > > Again, even with 512, please verify a few different distros and check that they run. Verified the few distro images available in my virt-test setup, we boot fine with 512MB memory. Will send an updated patch. Regards Nikunj