AlexEv1337
Member
In physical machines I have Ubuntu 16.04 with QEMU/KVM, virtual machines Ubuntu 16.04 too. Speed of disk writing under KVM extremely low, installation process doing more than day and time on time never finished at all. And speed of second machines 100 times less than fist. But this is brand new computer with fast disks. Why it working so slow? What I must to check?
# hdparm -Tt /dev/sda
/dev/sda:
Timing cached reads: 25588 MB in 1.99 seconds = 12861.67 MB/sec
Timing buffered disk reads: 1518 MB in 3.00 seconds = 505.46 MB/sec
# hdparm -Tt /dev/sdb
/dev/sdb:
Timing cached reads: 24748 MB in 1.99 seconds = 12435.68 MB/sec
Timing buffered disk reads: 1512 MB in 3.00 seconds = 503.95 MB/sec
# hdparm -Tt /dev/sdc
/dev/sdc:
Timing cached reads: 24766 MB in 1.99 seconds = 12444.51 MB/sec
Timing buffered disk reads: 1512 MB in 3.00 seconds = 503.83 MB/sec
# virsh domblkstat U226 sda --human
Device: sda
number of read operations: 15650
number of bytes read: 370658304
number of write operations: 1335
number of bytes written: 14706688
number of flush operations: 577
total duration of reads (ns): 895910866
total duration of writes (ns): 157488133
total duration of flushes (ns): 705676395
# virsh domblkstat U227 vda --human
Device: vda
number of read operations: 2890
number of bytes read: 29400064
number of write operations: 62919
number of bytes written: 3077697536
number of flush operations: 15855
total duration of reads (ns): 262241702
total duration of writes (ns): 56456643605
total duration of flushes (ns): 277285135
# virsh dominfo U226
Id: 3
Name: U226
UUID: 027a5df5-4211-4451-be4f-ca1bf9941e7b
OS Type: hvm
State: running
CPU(s): 2
CPU time: 114.4s
Max memory: 2097152 KiB
Used memory: 2097152 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: none
Security DOI: 0
# virsh dominfo U227
Id: 4
Name: U227
UUID: f1966b82-2bea-46ec-94b7-d0a52e6e32be
OS Type: hvm
State: running
CPU(s): 2
CPU time: 441.9s
Max memory: 2097152 KiB
Used memory: 2097152 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: none
Security DOI: 0
# virsh domblkerror U227
No errors found
# hdparm -Tt /dev/sda
/dev/sda:
Timing cached reads: 25588 MB in 1.99 seconds = 12861.67 MB/sec
Timing buffered disk reads: 1518 MB in 3.00 seconds = 505.46 MB/sec
# hdparm -Tt /dev/sdb
/dev/sdb:
Timing cached reads: 24748 MB in 1.99 seconds = 12435.68 MB/sec
Timing buffered disk reads: 1512 MB in 3.00 seconds = 503.95 MB/sec
# hdparm -Tt /dev/sdc
/dev/sdc:
Timing cached reads: 24766 MB in 1.99 seconds = 12444.51 MB/sec
Timing buffered disk reads: 1512 MB in 3.00 seconds = 503.83 MB/sec
# virsh domblkstat U226 sda --human
Device: sda
number of read operations: 15650
number of bytes read: 370658304
number of write operations: 1335
number of bytes written: 14706688
number of flush operations: 577
total duration of reads (ns): 895910866
total duration of writes (ns): 157488133
total duration of flushes (ns): 705676395
# virsh domblkstat U227 vda --human
Device: vda
number of read operations: 2890
number of bytes read: 29400064
number of write operations: 62919
number of bytes written: 3077697536
number of flush operations: 15855
total duration of reads (ns): 262241702
total duration of writes (ns): 56456643605
total duration of flushes (ns): 277285135
# virsh dominfo U226
Id: 3
Name: U226
UUID: 027a5df5-4211-4451-be4f-ca1bf9941e7b
OS Type: hvm
State: running
CPU(s): 2
CPU time: 114.4s
Max memory: 2097152 KiB
Used memory: 2097152 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: none
Security DOI: 0
# virsh dominfo U227
Id: 4
Name: U227
UUID: f1966b82-2bea-46ec-94b7-d0a52e6e32be
OS Type: hvm
State: running
CPU(s): 2
CPU time: 441.9s
Max memory: 2097152 KiB
Used memory: 2097152 KiB
Persistent: yes
Autostart: disable
Managed save: no
Security model: none
Security DOI: 0
# virsh domblkerror U227
No errors found