eG Monitoring
 

Measures reported by CorOSContImgTest

Images are utilized as read-only templates for building multiple containers. The containers so created will share common files and enhance disk usage and downloads on the containers. Once the containers are created, multiple applications can be installed on them. The applications can also be updated to a new version by simply building a new layer on the existing images rather than replacing the whole image or entirely rebuilding the containers. The containers can be mapped to a single image or to multiple images. If a single image is alone over-utilized in creating the containers or if any image remains unmapped to the containers, then such unmapped images will remain under-utilized but still occupy a considerable amount of disk space. If too many such unmapped images exists, then, new images could not be created and applications cannot be bundled to the existing images/containers. As a result, the disk space will be decreased while the disk usage will drastically increase along with a reduction in the building speed of the containers. This is why, administrators need to frequently check for the images and the disk space occupied by those images. The CorOSContImgTest does this check.

This test reports the total number of images that are available on the CRIO Container Engine. Using this test, administrators can figure out those images that are mapped to the containers and those that are not mapped to any containers. Likewise, administrators can also figure out the disk space utilization of the images that are mapped to the containers and the disk space utilization of the images that are not mapped to the containers. This way, administrators can figure out the images that are sparsely utilized, the images that are consuming too much of disk space etc and take remedial actions to restrict the disk space utilization of the images.

Outputs of the test : One set of results for the target CRIO Engine being monitored

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
total_images Indicates the total numberof images available in the CRIO Container Engine. Number  
image_container Indicates the number of images that are mapped to the containers launched by the CRIO Engine. Number Ideally, the value of this measure should be high. A low value for this measure indicates that more number of images are left idle and more disk space is occupied by unused images. This may cause potential space crunch on the disk.

The detailed diagnosis of this measure lists the images, size of the images and the containers to which the images are mapped.
image_not_container Indicates the number of images that are not mapped to the containers launched by the CRIO Engine. Number Ideally, the value of this measure should be low.

The detailed diagnosis of this measure lists the name of the images, Image ID and the size of each image.
size_img_container Indicates the amount of disk space utilized by the images that are mapped to the containers launched by the CRIO Engine. MB The detailed diagnosis of this measure lists the name of the images, image IDs, name of the containers and the size of the images
size_image_not_container Indicates the amount of disk space utilized by the images that were not mapped to the containers launched by the CRIO Engine. MB A high value of this measure indicates space crunch on the disk.

The detailed diagnosis of this measure lists the name of the images, image ID and the size of the images. Use the detailed diagnosis to identify the image that is consuming the maximum amount of disk space.