Is it possible to set resource limitation on disk(cinder volume)?

Environment

• Red Hat Open Stack
• Cinder

Issue

• set resource limitation on disk(cinder volume)?

Resolution

• cinder qos* commands for the same. Go through following example for more details:

# cinder qos-create low-iops consumer="front-end" read_iops_sec=10 write_iops_sec=10
+----------+-----------------------------------------------------+
| Property |                        Value                        |
+----------+-----------------------------------------------------+
| consumer |                      front-end                      |
|    id    |         79bc1bc6-555d-4c1b-9042-7051a50943be        |
|   name   |                       low-iops                      |
|  specs   | {u'write_iops_sec': u'10', u'read_iops_sec': u'10'} |
+----------+-----------------------------------------------------+

# cinder type-create low-iops
+--------------------------------------+----------+
|                  ID                  |   Name   |
+--------------------------------------+----------+
| 47e46918-d2d2-4624-bb16-77bba59199f9 | low-iops |
+--------------------------------------+----------+

# cinder qos-associate 79bc1bc6-555d-4c1b-9042-7051a50943be 47e46918-d2d2-4624-bb16-77bba59199f9

# cinder create --display-name slow --volume-type  low-iops 2
+---------------------+--------------------------------------+
|       Property      |                Value                 |
+---------------------+--------------------------------------+
|     attachments     |                  []                  |
|  availability_zone  |                 nova                 |
|       bootable      |                false                 |
|      created_at     |      2014-05-01T14:44:17.895541      |
| display_description |                 None                 |
|     display_name    |                 slow                 |
|          id         | af148419-4de5-428b-816c-e17dc33e765e |
|       metadata      |                  {}                  |
|         size        |                  2                   |
|     snapshot_id     |                 None                 |
|     source_volid    |                 None                 |
|        status       |               creating               |
|     volume_type     |               low-iops               |
+---------------------+--------------------------------------+

# nova volume-attach  e4ab6634-f0dd-4d2d-a12c-f20db23bf478 af148419-4de5-428b-816c-e17dc33e765e /dev/vdh
+----------+--------------------------------------+
| Property | Value                                |
+----------+--------------------------------------+
| device   | /dev/vdh                             |
| serverId | e4ab6634-f0dd-4d2d-a12c-f20db23bf478 |
| id       | af148419-4de5-428b-816c-e17dc33e765e |
| volumeId | af148419-4de5-428b-816c-e17dc33e765e |
+----------+--------------------------------------+

- Now from instance, try dd some content on /dev/vdh and monitor the speed:
---
# time dd if=/dev/zero of=/mnt/test.out bs=1M count=500 oflag=direct
---

For ex:
[root@test test]# mount |grep -i ext
/dev/vdc on /root/test type ext4 (rw,relatime,seclabel,data=ordered) <== with qos(slow)
/dev/vdd on /mnt type ext4 (rw,relatime,seclabel,data=ordered)   <== without qos(normal)


[root@test test]# dd if=/dev/zero of=/mnt/test.txt  bs=1M count=15  oflag=direct
15+0 records in
15+0 records out
15728640 bytes (16 MB) copied, 0.282361 s, 55.7 MB/s  <====


[root@test test]# dd if=/dev/zero of=/root/test/test.txt  bs=1M count=15  oflag=direct
15+0 records in
15+0 records out
15728640 bytes (16 MB) copied, 4.33381 s, 3.6 MB/s  <==== 

• QoS options:

 total_bytes_sec: the total allowed bandwidth for the guest per second
 read_bytes_sec: sequential read limitation
 write_bytes_sec: sequential write limitation
 total_iops_sec: the total allowed IOPS for the guest per second
 read_iops_sec: random read limitation
 write_iops_sec: random write limitation

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