similar to: Choosing best io elevator/scheduler for dom0

Can anyone explain how the disk elevator works and if there is anyway to tweak it? I have an email server which likely has a large number of read and write requests and was wandering if there was anyway to improve performance. Matt

In past on my machines with single drive or software RAID I have always had to change elevator to deadline. Mainly due to fact I was running email server with a great deal of I/O. Switching from CFQ to Deadline made a huge difference. I am wandering if with a hardware RAID controller should I still switch too Deadline or does the RAID controller do reordering etc. for me? Likely best answer is

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi everyone, I found an article about libvirt, and one thing that I have not seen anywhere else: > IMPORTANT: If you boot a Linux VM, you might want to add > “elevator=noop” to your Linux boot command line to force the disk > scheduler to let the host machine handle the disk writes > reorganisations (like tunnelling tcp over tcp, it

I'm having load problems on a server. The bottleneck appears to be disk IO. iostat would show ~100, under %util, during peak usage. i'm running things like clam antivirus, pop, exim, apache, mysql on the server. is there a way to check which process and which file is taking up disk IO? or see what is being written to the disk? i'm very puzzled as the amount of writes is 10 times

Greetings all- I'm on a quest to do some serious tuning to some of my production systems. All are on CentOS 5.x ranging from 5.0 to 5.4. I've been reading up on the various IO schedulers available in the kernel and I'm hoping some of you can lend some insightful suggestions. I typically have three classes of system in production: 1. Storage/DB - Backend nodes for the application

Hello, I'd like to set the io scheduler on some of the disks on our Dom0 (CentOS 5) to "deadline". The way I found to do this is with "echo deadline > /sys/block/sdb/queue/scheduler". What is the Right Way(TM) to set this automatically during boot? I sort of expected to use sysctl but it appears to only deal with pseudo-files under /proc/sys, not /sys. Also

I am trying to install the binary version of xen 3.1. When I boot, after some console output, I get the following: :: Loading Initramfs scsi_mod: no version for "struct_module" found: kernel tainted. SCSI subsystem intialized :: Running Hook [udev] :: Loading udev...input: AT Translated Set 2 keyboard as /class/inpt/input0 done. :: Running Hook [keymap] :: Loading keymap...Cannot find

As long as I'm still awake, I tried to install CentOS 5 (earlier) from a DVD I downloaded via bittorrent about a week or so ago. It boots fine, but once it starts to load the kernel (in graphics mode), it gets to the point where it announces the four i/o schedulers and then stops dead. No disk activity, no DVD activity, nada. Is there a known problem here and if so what, or is this a new

Hello, I just wrote a step-by-step tutorial how to install the latest Xen 4.0.1 hypervisor on Fedora 13 (x86_64) host from src.rpm packages, and the pvops dom0 kernel from git repository. Check it out: http://wiki.xensource.com/xenwiki/Fedora13Xen4Tutorial It also shows how to install various Xen PV guests using the native distro installers: - CentOS 5.5 - Fedora 13 - Ubuntu 10.04 LTS

Hello, I just wrote a step-by-step tutorial how to install the latest Xen 4.0.1 hypervisor on Fedora 13 (x86_64) host from src.rpm packages, and the pvops dom0 kernel from git repository. Check it out: http://wiki.xensource.com/xenwiki/Fedora13Xen4Tutorial It also shows how to install various Xen PV guests using the native distro installers: - CentOS 5.5 - Fedora 13 - Ubuntu 10.04 LTS

On Sat, 2015-05-09 at 14:07 +0200, Romain Mourier wrote: > On 09/05/2015 13:25, Ian Campbell wrote: > > On Sat, 2015-05-09 at 03:41 +0200, Romain Mourier wrote: > > [...] > >> xen-create-image --hostname=test0 --lvm=raid10 --fs=ext4 > >> --bridge=br-lan --dhcp --dist=jessie > > [...] > >> root at hv0:~# xl create /etc/xen/test0.cfg && xl

On a selection of boxes, ntpd running in Xen Dom0 reproducibly exhibits extermely high noise/jitter. Switching back to -default, non-xen kernel ntpd runs with very low jitter/noise. Question -- how can I ''tame'' ntpd noise & jitter when running in Dom0? Is the problem a config issue, or a bug? Already reported this downstream; everybody''s "stumped".

On a selection of boxes, ntpd running in Xen Dom0 reproducibly exhibits extermely high noise/jitter. Switching back to -default, non-xen kernel ntpd runs with very low jitter/noise. Question -- how can I ''tame'' ntpd noise & jitter when running in Dom0? Is the problem a config issue, or a bug? Already reported this downstream; everybody''s "stumped".

On 09/05/2015 13:25, Ian Campbell wrote: > On Sat, 2015-05-09 at 03:41 +0200, Romain Mourier wrote: > [...] >> xen-create-image --hostname=test0 --lvm=raid10 --fs=ext4 >> --bridge=br-lan --dhcp --dist=jessie > [...] >> root at hv0:~# xl create /etc/xen/test0.cfg && xl console test0 > What does /etc/xen/test0.cfg contain? I suspect it is reusing the dom0

Hi, I encounter a problem that has puzzled me for a long time.On a Xen virtualization platform, some VMs ,whose virtual disks are image files ,are running in DomUs.Under this situation ,does the Dom0 cache the pages from the VMs?Does the filesystem in Dom0 see the VMs as general processes? HXK _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com

Hey George, I was wondering if you could explain in simple terms how the scheduler would handle per-physical CPU when there are say 16 guests (each guest is using one VCPU), 32 physical CPUs and dom0 is not restricted to any CPUs. Would the scheduler per physical CPU schedule: guest, dom0, guest, dom0, and so on; or would it be more random? (I assume that both guest and dom0 would do a hypercall

after shutdown many domu, the memory is not release to dom0, before:  host: 8g phy memory 16g swap (4g used) dom0: 600m domu: consumed all memory, no new domu could be created after shutdown many domu:  host: 8g phy memory 16g swap (4g used) dom0: 600m domu: 2g why memory of dom0 is still 600m? how to release more to dom0? pls advise. Yahoo!香港提供網上安全攻略，教你如何防範黑客! 請前往

Hi, short question: Which schedulers are recommended on running a samba smb server using > 1000 files but high I/O on reads/writes on those files? - Julian Wichtiger Hinweis: Der Inhalt dieser E-Mail ist vertraulich und ausschlie?lich f?r den bezeichneten Adressaten bestimmt. Wenn Sie nicht der vorgesehene Adressat dieser E-Mail oder dessen Vertreter sein sollten, so beachten Sie bitte,

Hello list! I''ve noticed this problem a couple of times now.. so I''m wondering if it''s a known bug? Symptoms: After "long" dom0 uptime (174 days when it happened now, was something similar on previous times too) cannot start new pv domUs anymore.. pygrub runs and boots the kernel, but kernel newer gets to actually running initrd and the console output

Odd question I know. I am looking for source for as recent a kernel as possible running the old style xenlinux/xenified kernel (i.e. capable of running the xen3.3.x hypervisor). Any ideas where I can get this - preferably in git form? I think Stefano Stabellini had something that worked up to 2.6.36 (from memory). And yes, we would all prefer all our customers moved to xen4 but this is difficult