hi I am new user for xen i have VM and i run java application on it .. i want to empty cache for vm i do that with echo 3 >/proc/sys/vm/drop_caches and the same command in physical machine but there is not any effect i think the vm have own cache in xen how can empty xen disk cache?? thanks _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
________________________________ From: Radhya sahal <rad_cs_2006@yahoo.com> To: xen-users@lists.xensource.com Sent: Friday, July 22, 2011 5:36 PM Subject: [Xen-users] how can empty xen disk cache?? hi I am new user for xen i have VM and i run java application on it .. i want to empty cache for vm i do that with echo 3 >/proc/sys/vm/drop_caches and the same command in physical machine but there is not any effect i think the vm have own cache in xen how can empty xen disk cache?? thanks check options in /etc/sysconfig/xendomains or (etc/default -- in debian) and turn off save/restore. -- Mark _______________________________________________ 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
On Fri, Jul 22, 2011 at 07:11:57PM -0700, Mark Pryor wrote:> -------------------------------------------------------------------------- > > From: Radhya sahal <rad_cs_2006@yahoo.com> > To: xen-users@lists.xensource.com > Sent: Friday, July 22, 2011 5:36 PM > Subject: [Xen-users] how can empty xen disk cache?? > > hi > I am new user for xen > i have VM and i run java application on it .. > i want to empty cache for vm > i do that with > echo 3 >/proc/sys/vm/drop_caches > and the same command in physical machine > but there is not any effect > i think the vm have own cache in xen > how can empty xen disk cache?? > thanks > > check options in /etc/sysconfig/xendomains or (etc/default -- in debian) > and turn off save/restore. >I don''t think the question has nothing to do with save/restore. Dom0 does not usually cache domU disk IO, unless you''re using file: backend. Which disk backends are you using? tap:aio and phy: backends bypass the dom0 page cache, and thus those backends don''t have any caching in xen dom0. Xen hypervisor itself does not have cache of any kind. -- Pasi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
thank''s Mark and Pasi, i use centos and xen ,either dom0 and vm run centos 5.5. in the vm i run java application which it reads e.g( text file ,table in database,....). in the first read get actual total run-time but if i try to read more than one . the file be in cache and get a very very short time ..!!! although i try to empty the vm cache and physical(dom0) cache!!! echo 3 >/proc/sys/vm/drop_caches i want to read more than one to calculate the the right average run-time for the vm resource allocation and compare this averages with other vm resource allocations ??? --- On Sat, 7/23/11, Pasi Kärkkäinen <pasik@iki.fi> wrote: From: Pasi Kärkkäinen <pasik@iki.fi> Subject: Re: [Xen-users] how can empty xen disk cache?? To: "Mark Pryor" <tlviewer@yahoo.com> Cc: "Radhya sahal" <rad_cs_2006@yahoo.com>, "xen-users@lists.xensource.com" <xen-users@lists.xensource.com> Date: Saturday, July 23, 2011, 6:44 AM On Fri, Jul 22, 2011 at 07:11:57PM -0700, Mark Pryor wrote:> -------------------------------------------------------------------------- > > From: Radhya sahal <rad_cs_2006@yahoo.com> > To: xen-users@lists.xensource.com > Sent: Friday, July 22, 2011 5:36 PM > Subject: [Xen-users] how can empty xen disk cache?? > > hi > I am newuser for xen> i have VM and i run java application on it .. > i want to empty cache for vm > i do that with > echo 3 >/proc/sys/vm/drop_caches > and the same command in physical machine > but there is not any effect > i think the vm have own cache in xen > how can empty xen disk cache?? > thanks > > check options in /etc/sysconfig/xendomains or (etc/default -- in debian) > and turn off save/restore. >I don''t think the question has nothing to do with save/restore. Dom0 does not usually cache domU disk IO, unless you''re using file: backend. Which disk backends are you using? tap:aio and phy: backends bypass the dom0 page cache, and thus those backends don''t have any caching in xen dom0. Xen hypervisor itself does not have cache of any kind. -- Pasi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sat, Jul 23, 2011 at 06:46:58PM -0700, Radhya sahal wrote:> thank''s Mark and Pasi, > i use centos and xen ,either dom0 and vm run centos 5.5. > in the vm i run java application which it reads e.g( text file ,table in > database,....). > in the first read get actual total run-time but if i try to read more than > one . the file be in cache and get a very very short time ..!!! > although i try to empty the vm cache and physical(dom0) cache!!! > echo 3 >/proc/sys/vm/drop_caches > i want to read more than one to calculate the the right average run-time for > the vm resource allocation and compare this averages with other vm resource > allocations ??? >I repeat the question: Which disk backend are you using in dom0 for the VM ? -- Pasi> --- On Sat, 7/23/11, Pasi Kärkkäinen <pasik@iki.fi> wrote: > > From: Pasi Kärkkäinen <pasik@iki.fi> > Subject: Re: [Xen-users] how can empty xen disk cache?? > To: "Mark Pryor" <tlviewer@yahoo.com> > Cc: "Radhya sahal" <rad_cs_2006@yahoo.com>, > "xen-users@lists.xensource.com" <xen-users@lists.xensource.com> > Date: Saturday, July 23, 2011, 6:44 AM > > On Fri, Jul 22, 2011 at 07:11:57PM -0700, Mark Pryor wrote: > > > -------------------------------------------------------------------------- > > > > From: Radhya sahal <rad_cs_2006@yahoo.com> > > To: xen-users@lists.xensource.com > > Sent: Friday, July 22, 2011 5:36 PM > > Subject: [Xen-users] how can empty xen disk cache?? > > > > hi > > I am new user for xen > > i have VM and i run java application on it .. > > i want to empty cache for vm > > i do that with > > echo 3 >/proc/sys/vm/drop_caches > > and the same command in physical machine > > but there is not any effect > > i think the vm have own cache in xen > > how can empty xen disk cache?? > > thanks > > > > check options in /etc/sysconfig/xendomains or (etc/default -- in > debian) > > and turn off save/restore. > > > > I don''t think the question has nothing to do with save/restore. > > Dom0 does not usually cache domU disk IO, unless you''re using file: > backend. > Which disk backends are you using? > > tap:aio and phy: backends bypass the dom0 page cache, > and thus those backends don''t have any caching in xen dom0. > > Xen hypervisor itself does not have cache of any kind. > > -- Pasi_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
--- On Mon, 7/25/11, Pasi Kärkkäinen <pasik@iki.fi> wrote: T hank''s Pasi , I tried to run this command drop cache in VM and physical(dom0) before i put my question in the group !!! echo 3 >/proc/sys/vm/drop_caches dom0 actually empty cache but there is not any effect the files in VM still in the cache?? On Sun, Jul 24, 2011 at 08:45:49AM -0700, Radhya sahal wrote:> HI Pasi, > thanks for your cooperation,this the XML configuration VM file > name = "vm2" > uuid = "70bf5c52-91ed-fbd5-4eb7-f6acc52c3168" > maxmem = 2277 > memory = 1024 > vcpus = 1 > bootloader = "/usr/bin/pygrub" > kernel = "/var/lib/xen/boot_kernel.313tN4" > ramdisk = "/var/lib/xen/boot_ramdisk.vV9Kd9" > extra = "ro root=/dev/VolGroup00/LogVol00 rhgb quiet" > on_poweroff = "destroy" > on_reboot = "restart" > on_crash = "restart" > vfb = [ "type=vnc,vncunused=1,keymap=en-us" ] > disk = [ "tap:aio:/var/lib/xen/images/vm2.img,xvda,w" ] > vif = [ > "mac=00:16:36:1e:3a:dc,bridge=virbr0,script=vif-bridge,vifname=vif2.0" ] > i am new user for xen so i think maybe you the backend in xen tap:aio ?? > how can be sure the VM cache is empty with out restart VM?? >So yeah, you''re using tap:aio: backend. You shouldn''t have any dom0 caching then. Do you perhaps have a RAID controller with memory cache module? You could try running the "drop caches" in dom0, and see if that changes anything.. -- Pasi> > --- On Sun, 7/24/11, Pasi Kärkkäinen <pasik@iki.fi> wrote: > > From: Pasi Kärkkäinen <pasik@iki.fi> > Subject: Re: [Xen-users] how can empty xen disk cache?? > To: "Radhya sahal" <rad_cs_2006@yahoo.com> > Cc: "xen list" <xen-users@lists.xensource.com> > Date: Sunday, July 24, 2011, 3:21 AM > > On Sat, Jul 23, 2011 at 06:46:58PM -0700, Radhya sahal wrote: > > thank''s Mark and Pasi, > > i use centos and xen ,either dom0 and vm run centos 5.5. > > in the vm i run java application which it reads e.g( text file ,table > in > > database,....). > > in the first read get actual total run-time but if i try to read more > than > > one . the file be in cache and get a very very short time ..!!! > > although i try to empty the vm cache and physical(dom0) cache!!! > > echo 3 >/proc/sys/vm/drop_caches > > i want to read more than one to calculate the the right average > run-time for > > the vm resource allocation and compare this averages with other vm > resource > > allocations ??? > > > > I repeat the question: Which disk backend are you using in dom0 for the VM > ? > > -- Pasi > > > --- On Sat, 7/23/11, Pasi Kärkkäinen <[1]pasik@iki.fi> wrote: > > > > From: Pasi Kärkkäinen <[2]pasik@iki.fi> > > Subject: Re: [Xen-users] how can empty xen disk cache?? > > To: "Mark Pryor" <[3]tlviewer@yahoo.com> > > Cc: "Radhya sahal" <[4]rad_cs_2006@yahoo.com>, > > "[5]xen-users@lists.xensource.com" > <[6]xen-users@lists.xensource.com> > > Date: Saturday, July 23, 2011, 6:44 AM > > > > On Fri, Jul 22, 2011 at 07:11:57PM -0700, Mark Pryor wrote: > > > > > > -------------------------------------------------------------------------- > > > > > > From: Radhya sahal <[7]rad_cs_2006@yahoo.com> > > > To: [8]xen-users@lists.xensource.com > > > Sent: Friday, July 22, 2011 5:36 PM > > > Subject: [Xen-users] how can empty xen disk cache?? > > > > > > hi > > > I am new user for xen > > > i have VM and i run java application on it .. > > > i want to empty cache for vm > > > i do that with > > > echo 3 >/proc/sys/vm/drop_caches > > > and the same command in physical machine > > > but there is not any effect > > > i think the vm have own cache in xen > > > how can empty xen disk cache?? > > > thanks > > > > > > check options in /etc/sysconfig/xendomains or (etc/default -- > in > > debian) > > > and turn off save/restore. > > > > > > > I don''t think the question has nothing to do with save/restore. > > > > Dom0 does not usually cache domU disk IO, unless you''re using file: > > backend. > > Which disk backends are you using? > > > > tap:aio and phy: backends bypass the dom0 page cache, > > and thus those backends don''t have any caching in xen dom0. > > > > Xen hypervisor itself does not have cache of any kind. > > > > -- Pasi > > References > > Visible links > 1. file:///mc/compose?to=pasik@iki.fi > 2. file:///mc/compose?to=pasik@iki.fi > 3. file:///mc/compose?to=tlviewer@yahoo.com > 4. file:///mc/compose?to=rad_cs_2006@yahoo.com > 5. file:///mc/compose?to=xen-users@lists.xensource.com > 6. file:///mc/compose?to=xen-users@lists.xensource.com > 7. file:///mc/compose?to=rad_cs_2006@yahoo.com > 8. file:///mc/compose?to=xen-users@lists.xensource.com_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Mon, Jul 25, 2011 at 12:24:55PM -0700, Radhya sahal wrote:> --- On Mon, 7/25/11, Pasi Kärkkäinen <pasik@iki.fi> wrote: > > T hank''s Pasi , > I tried to run this command drop cache in VM and physical(dom0) before i > put my question in the group !!! > echo 3 >/proc/sys/vm/drop_caches > dom0 actually empty cache but there is not any effect the files in VM > still in the cache?? >So then Xen dom0 is NOT caching anything. Your problem is somewhere else! Perhaps hardware RAID controller (with memory cache onboard) ? -- Pasi> On Sun, Jul 24, 2011 at 08:45:49AM -0700, Radhya sahal wrote: > > HI Pasi, > > thanks for your cooperation,this the XML configuration VM file > > name = "vm2" > > uuid = "70bf5c52-91ed-fbd5-4eb7-f6acc52c3168" > > maxmem = 2277 > > memory = 1024 > > vcpus = 1 > > bootloader = "/usr/bin/pygrub" > > kernel = "/var/lib/xen/boot_kernel.313tN4" > > ramdisk = "/var/lib/xen/boot_ramdisk.vV9Kd9" > > extra = "ro root=/dev/VolGroup00/LogVol00 rhgb quiet" > > on_poweroff = "destroy" > > on_reboot = "restart" > > on_crash = "restart" > > vfb = [ "type=vnc,vncunused=1,keymap=en-us" ] > > disk = [ "tap:aio:/var/lib/xen/images/vm2.img,xvda,w" ] > > vif = [ > > > "mac=00:16:36:1e:3a:dc,bridge=virbr0,script=vif-bridge,vifname=vif2.0" ] > > i am new user for xen so i think maybe you the backend in xen > tap:aio ?? > > how can be sure the VM cache is empty with out restart VM?? > > > > So yeah, you''re using tap:aio: backend. > You shouldn''t have any dom0 caching then. > > Do you perhaps have a RAID controller with memory cache module? > > You could try running the "drop caches" in dom0, and see if that changes > anything.. > > -- Pasi > > > > > --- On Sun, 7/24/11, Pasi Kärkkäinen <[1]pasik@iki.fi> wrote: > > > > From: Pasi Kärkkäinen <[2]pasik@iki.fi> > > Subject: Re: [Xen-users] how can empty xen disk cache?? > > To: "Radhya sahal" <[3]rad_cs_2006@yahoo.com> > > Cc: "xen list" <[4]xen-users@lists.xensource.com> > > Date: Sunday, July 24, 2011, 3:21 AM > > > > On Sat, Jul 23, 2011 at 06:46:58PM -0700, Radhya sahal wrote: > > > thank''s Mark and Pasi, > > > i use centos and xen ,either dom0 and vm run centos 5.5. > > > in the vm i run java application which it reads e.g( text file > ,table > > in > > > database,....). > > > in the first read get actual total run-time but if i try to > read more > > than > > > one . the file be in cache and get a very very short time > ..!!! > > > although i try to empty the vm cache and physical(dom0) > cache!!! > > > echo 3 >/proc/sys/vm/drop_caches > > > i want to read more than one to calculate the the right > average > > run-time for > > > the vm resource allocation and compare this averages with > other vm > > resource > > > allocations ??? > > > > > > > I repeat the question: Which disk backend are you using in dom0 for > the VM > > ? > > > > -- Pasi > > > > > --- On Sat, 7/23/11, Pasi Kärkkäinen <[1][5]pasik@iki.fi> > wrote: > > > > > > From: Pasi Kärkkäinen <[2][6]pasik@iki.fi> > > > Subject: Re: [Xen-users] how can empty xen disk cache?? > > > To: "Mark Pryor" <[3][7]tlviewer@yahoo.com> > > > Cc: "Radhya sahal" <[4][8]rad_cs_2006@yahoo.com>, > > > "[5][9]xen-users@lists.xensource.com" > > <[6][10]xen-users@lists.xensource.com> > > > Date: Saturday, July 23, 2011, 6:44 AM > > > > > > On Fri, Jul 22, 2011 at 07:11:57PM -0700, Mark Pryor wrote: > > > > > > > > > > -------------------------------------------------------------------------- > > > > > > > > From: Radhya sahal <[7][11]rad_cs_2006@yahoo.com> > > > > To: [8][12]xen-users@lists.xensource.com > > > > Sent: Friday, July 22, 2011 5:36 PM > > > > Subject: [Xen-users] how can empty xen disk cache?? > > > > > > > > hi > > > > I am new user for xen > > > > i have VM and i run java application on it .. > > > > i want to empty cache for vm > > > > i do that with > > > > echo 3 >/proc/sys/vm/drop_caches > > > > and the same command in physical machine > > > > but there is not any effect > > > > i think the vm have own cache in xen > > > > how can empty xen disk cache?? > > > > thanks > > > > > > > > check options in /etc/sysconfig/xendomains or > (etc/default -- > > in > > > debian) > > > > and turn off save/restore. > > > > > > > > > > I don''t think the question has nothing to do with > save/restore. > > > > > > Dom0 does not usually cache domU disk IO, unless you''re > using file: > > > backend. > > > Which disk backends are you using? > > > > > > tap:aio and phy: backends bypass the dom0 page cache, > > > and thus those backends don''t have any caching in xen dom0. > > > > > > Xen hypervisor itself does not have cache of any kind. > > > > > > -- Pasi > > > > References > > > > Visible links > > 1. file:///mc/compose?to=[13]pasik@iki.fi > > 2. file:///mc/compose?to=[14]pasik@iki.fi > > 3. file:///mc/compose?to=[15]tlviewer@yahoo.com > > 4. file:///mc/compose?to=[16]rad_cs_2006@yahoo.com > > 5. file:///mc/compose?to=[17]xen-users@lists.xensource.com > > 6. file:///mc/compose?to=[18]xen-users@lists.xensource.com > > 7. file:///mc/compose?to=[19]rad_cs_2006@yahoo.com > > 8. file:///mc/compose?to=[20]xen-users@lists.xensource.com > > References > > Visible links > 1. file:///mc/compose?to=pasik@iki.fi > 2. file:///mc/compose?to=pasik@iki.fi > 3. file:///mc/compose?to=rad_cs_2006@yahoo.com > 4. file:///mc/compose?to=xen-users@lists.xensource.com > 5. file:///mc/compose?to=pasik@iki.fi > 6. file:///mc/compose?to=pasik@iki.fi > 7. file:///mc/compose?to=tlviewer@yahoo.com > 8. file:///mc/compose?to=rad_cs_2006@yahoo.com > 9. file:///mc/compose?to=xen-users@lists.xensource.com > 10. file:///mc/compose?to=xen-users@lists.xensource.com > 11. file:///mc/compose?to=rad_cs_2006@yahoo.com > 12. file:///mc/compose?to=xen-users@lists.xensource.com > 13. file:///mc/compose?to=pasik@iki.fi > 14. file:///mc/compose?to=pasik@iki.fi > 15. file:///mc/compose?to=tlviewer@yahoo.com > 16. file:///mc/compose?to=rad_cs_2006@yahoo.com > 17. file:///mc/compose?to=xen-users@lists.xensource.com > 18. file:///mc/compose?to=xen-users@lists.xensource.com > 19. file:///mc/compose?to=rad_cs_2006@yahoo.com > 20. file:///mc/compose?to=xen-users@lists.xensource.com_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users