I run CloudStack 4.3 using KVM on an Intel(R) Xeon(R) CPU E5-2620 on Ubuntu 14.04 LTS. When I first start a virtual machine it runs quickly. Over the course of the day it slows down to acceptable. After two days run time, it is virtually unusable. Restarting the VM brings it back to full speed.
This appears to affect both Windows and Linux VMs, though it appears to affect the most heavily machines the most.
I have disabled swap on the host machine. Running iotop, top, and iftop doesn't show anything out of the ordinary. Additionally, the CPUs themselves don't appear to be overtaxed; most of them are running at a lower frequency, though they do spin up when load increases.
No warnings or errors appear in the CloudStack log.
-- System Info --
The other 23 cores are identical.
processor : 23
vendor_id : GenuineIntel
cpu family : 6
model : 45
model name : Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz
stepping : 7
microcode : 0x710
cpu MHz : 2001.000
cache size : 15360 KB
physical id : 1
siblings : 12
core id : 5
cpu cores : 6
apicid : 43
initial apicid : 43
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
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 cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips : 4002.70
clflush size : 64
cache_alignment : 64
address sizes : 46 bits physical, 48 bits virtual
power management:
# cat /proc/cpuinfo | grep MHz | sort | uniq -c
16 cpu MHz : 1200.000
8 cpu MHz : 2001.000
#free
total used free shared buffers cached
Mem: 65943828 65186960 756868 1744 242204 28397924
-/+ buffers/cache: 36546832 29396996
Swap: 0 0 0
df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/cloud--vg-root 166G 6.3G 152G 4% /
none 4.0K 0 4.0K 0% /sys/fs/cgroup
udev 32G 4.0K 32G 1% /dev
tmpfs 6.3G 1.4M 6.3G 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 32G 0 32G 0% /run/shm
none 100M 0 100M 0% /run/user
/dev/sdc1 236M 37M 188M 17% /boot
/dev/mapper/cloud--vg-lv_images 7.3T 1.3T 5.7T 18% /srv/images
172.27.1.1:/srv/images/primary 7.3T 1.3T 5.7T 18% /mnt/cf428915-5736-30ce-b0b1-0535e28ce1b9