12:13 p.m.
Hi There,
I've moved some Windows2012 with MSSQL VMs from an hold ESXi 5.5 machine
to a more recent and powerful machine running Fedora 24 x86_64 and related libvirt + KVM
virtualization. I've moved the VMs filesystem to LVM slices and installed the VirtIO
drivers
in to all Windows VMs. I've also set both Disk and Network interface to work using
VirtIO.
So far so good everything works pretty fine. Now I would like to tune at best the MSSQL
VM
for both Disk and Network interfaces in order to get the best performance possible.
Regarding network interface I've set it to work as bridge instead to go through to
macvtap, so I'm
not sure what is the best in this case.
Regarding disk, since it's LVM I've chosen to go to cache mode none and IO mode
native. Also
here cannot judge what's the best setup for the workload. I'm undecided to use IO
mode threads
along directsync cache mode.
Finally I've set "ionice -c 1 -p <qemu-pid> -n 0" and "renice -n
-10 <qemu-pid>" for the interested
VM that I want to get best performance possible.
Even with the above setup, the MSSQL VM has performance similar to the old machine
running
ESXi 5.5, so does anyone can suggest where too look at and/or what would be the right
setup?
Thanks in advance.
Roberto Fichera
11:06 p.m.
Hi Roberto,
What is the cpu and memory configuration of your guest? Are you
pinning to dedicated CPUs, are you exposing host topology and cpu
features, do you have dedicated I/O threads? Are you backing the guest
memory with hugepages? All of the above will likely increase
performance and minimise noise.
Cheers,
On 6 December 2016 at 05:13, Roberto Fichera <kernel(a)tekno-soft.it> wrote:
Hi There,
I've moved some Windows2012 with MSSQL VMs from an hold ESXi 5.5 machine
to a more recent and powerful machine running Fedora 24 x86_64 and related libvirt + KVM
virtualization. I've moved the VMs filesystem to LVM slices and installed the VirtIO
drivers
in to all Windows VMs. I've also set both Disk and Network interface to work using
VirtIO.
So far so good everything works pretty fine. Now I would like to tune at best the MSSQL
VM
for both Disk and Network interfaces in order to get the best performance possible.
Regarding network interface I've set it to work as bridge instead to go through to
macvtap, so I'm
not sure what is the best in this case.
Regarding disk, since it's LVM I've chosen to go to cache mode none and IO mode
native. Also
here cannot judge what's the best setup for the workload. I'm undecided to use IO
mode threads
along directsync cache mode.
Finally I've set "ionice -c 1 -p <qemu-pid> -n 0" and "renice -n
-10 <qemu-pid>" for the interested
VM that I want to get best performance possible.
Even with the above setup, the MSSQL VM has performance similar to the old machine
running
ESXi 5.5, so does anyone can suggest where too look at and/or what would be the right
setup?
Thanks in advance.
Roberto Fichera
_______________________________________________
libvirt-users mailing list
libvirt-users(a)redhat.com
https://www.redhat.com/mailman/listinfo/libvirt-users
--
Cheers,
~Blairo
2:01 a.m.
On 12/06/2016 06:06 AM, Blair Bethwaite wrote:
Hi Roberto,
Hi Blair
What is the cpu and memory configuration of your guest?
I've set to copy host configuration (16 cores) and memory is set to 24GB, host has
64GB.
Guest is Windows 2012 64bits version
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 16
On-line CPU(s) list: 0-15
Thread(s) per core: 2
Core(s) per socket: 8
Socket(s): 1
NUMA node(s): 1
Vendor ID: GenuineIntel
CPU family: 6
Model: 79
Model name: Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
Stepping: 1
CPU MHz: 1200.219
CPU max MHz: 3000.0000
CPU min MHz: 1200.0000
BogoMIPS: 4194.79
Virtualization: VT-x
L1d cache: 32K
L1i cache: 32K
L2 cache: 256K
L3 cache: 20480K
NUMA node0 CPU(s): 0-15
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
pse36 clflush dts acpi mmx fxsr
sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts
rep_good nopl xtopology
nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3
sdbg fma cx16 xtpr pdcm pcid
dca sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm
abm 3dnowprefetch epb
intel_pt tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2
erms invpcid rtm cqm rdseed
adx smap xsaveopt cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local dtherm ida arat pln
pts
Are you pinning to dedicated CPUs,
no
are you exposing host topology and cpu
features,
Yes
do you have dedicated I/O threads?
if you are talking about disk I/O, no. Should I do that?
Are you backing the guest memory with hugepages?
Don't know, how can I check or set it?
All of the above will likely increase performance and minimise
noise.
Cheers,
On 6 December 2016 at 05:13, Roberto Fichera <kernel(a)tekno-soft.it> wrote:
> Hi There,
>
> I've moved some Windows2012 with MSSQL VMs from an hold ESXi 5.5 machine
> to a more recent and powerful machine running Fedora 24 x86_64 and related libvirt +
KVM
> virtualization. I've moved the VMs filesystem to LVM slices and installed the
VirtIO drivers
> in to all Windows VMs. I've also set both Disk and Network interface to work
using VirtIO.
> So far so good everything works pretty fine. Now I would like to tune at best the
MSSQL VM
> for both Disk and Network interfaces in order to get the best performance possible.
>
> Regarding network interface I've set it to work as bridge instead to go through
to macvtap, so I'm
> not sure what is the best in this case.
>
> Regarding disk, since it's LVM I've chosen to go to cache mode none and IO
mode native. Also
> here cannot judge what's the best setup for the workload. I'm undecided to
use IO mode threads
> along directsync cache mode.
>
> Finally I've set "ionice -c 1 -p <qemu-pid> -n 0" and
"renice -n -10 <qemu-pid>" for the interested
> VM that I want to get best performance possible.
>
> Even with the above setup, the MSSQL VM has performance similar to the old machine
running
> ESXi 5.5, so does anyone can suggest where too look at and/or what would be the right
setup?
>
> Thanks in advance.
> Roberto Fichera
>
>
> _______________________________________________
> libvirt-users mailing list
> libvirt-users(a)redhat.com
> https://www.redhat.com/mailman/listinfo/libvirt-users
8:42 p.m.
Hi Roberto,
On 6 December 2016 at 19:01, Roberto Fichera <kernel(a)tekno-soft.it> wrote:
I've set to copy host configuration (16 cores) and memory is set
to 24GB, host has 64GB.
Guest is Windows 2012 64bits version
Is the guest configured with 16 cpus or 16 cores?
> Are you pinning to dedicated CPUs,
no
I would, to ensure cpu or cache performance is absolutely not a
problem, and it's simple to do (see vcpupin).
> are you exposing host topology and cpu
> features,
Yes
So you have something like:
<cpu mode='host-passthrough'>
<topology sockets='1' cores='8' threads='2'/>
In your domain xml?
> do you have dedicated I/O threads?
if you are talking about disk I/O, no. Should I do that?
Hard to say what the problem is without a lot more information - maybe
the system in question is performance limited by the DB design...
But if you are bottlenecking on I/O in the guest whilst the host seems
to have more I/O available then you probably want to consider tuning
this:
https://libvirt.org/formatdomain.html#elementsIOThreadsAllocation
> Are you backing the guest memory with hugepages?
Don't know, how can I check or set it?
You can either use transparent huge pages (assuming you are not doing
any PCI passthrough), or create a static hugepage allocation for
guests. Search for documentation specific to your OS.
--
Cheers,
~Blairo
2907
days inactive
2909
days old
3 comments
2 participants
participants (2)
-
Blair Bethwaite -
Roberto Fichera