Modify allocatable storage to ephemeral-storage (#5490)

Update the doc to use ephemeral-storage instead of storage
This commit is contained in:
Jing Xu
2017-09-19 11:43:07 -07:00
committed by Steve Perry
parent af7c064877
commit f93a513d88
@@ -42,7 +42,7 @@ on each node.
`Allocatable` on a Kubernetes node is defined as the amount of compute resources `Allocatable` on a Kubernetes node is defined as the amount of compute resources
that are available for pods. The scheduler does not over-subscribe that are available for pods. The scheduler does not over-subscribe
`Allocatable`. `CPU`, `memory` and `storage` are supported as of now. `Allocatable`. `CPU`, `memory` and `ephemeral-storage` are supported as of now.
Node Allocatable is exposed as part of `v1.Node` object in the API and as part Node Allocatable is exposed as part of `v1.Node` object in the API and as part
of `kubectl describe node` in the CLI. of `kubectl describe node` in the CLI.
@@ -77,7 +77,7 @@ be configured to use the `systemd` cgroup driver.
### Kube Reserved ### Kube Reserved
- **Kubelet Flag**: `--kube-reserved=[cpu=100m][,][memory=100Mi][,][storage=1Gi]` - **Kubelet Flag**: `--kube-reserved=[cpu=100m][,][memory=100Mi][,][ephemeral-storage=1Gi]`
- **Kubelet Flag**: `--kube-reserved-cgroup=` - **Kubelet Flag**: `--kube-reserved-cgroup=`
`kube-reserved` is meant to capture resource reservation for kubernetes system `kube-reserved` is meant to capture resource reservation for kubernetes system
@@ -107,7 +107,7 @@ exist. Kubelet will fail if an invalid cgroup is specified.
### System Reserved ### System Reserved
- **Kubelet Flag**: `--system-reserved=[cpu=100mi][,][memory=100Mi][,][storage=1Gi]` - **Kubelet Flag**: `--system-reserved=[cpu=100mi][,][memory=100Mi][,][ephemeral-storage=1Gi]`
- **Kubelet Flag**: `--system-reserved-cgroup=` - **Kubelet Flag**: `--system-reserved-cgroup=`
@@ -135,7 +135,7 @@ Memory pressure at the node level leads to System OOMs which affects the entire
node and all pods running on it. Nodes can go offline temporarily until memory node and all pods running on it. Nodes can go offline temporarily until memory
has been reclaimed. To avoid (or reduce the probability of) system OOMs kubelet has been reclaimed. To avoid (or reduce the probability of) system OOMs kubelet
provides [`Out of Resource`](./out-of-resource.md) management. Evictions are provides [`Out of Resource`](./out-of-resource.md) management. Evictions are
supported for `memory` and `storage` only. By reserving some memory via supported for `memory` and `ephemeral-storage` only. By reserving some memory via
`--eviction-hard` flag, the `kubelet` attempts to `evict` pods whenever memory `--eviction-hard` flag, the `kubelet` attempts to `evict` pods whenever memory
availability on the node drops below the reserved value. Hypothetically, if availability on the node drops below the reserved value. Hypothetically, if
system daemons did not exist on a node, pods cannot use more than `capacity - system daemons did not exist on a node, pods cannot use more than `capacity -
@@ -191,8 +191,8 @@ So expect a drop in `Allocatable` capacity in future releases.
Here is an example to illustrate Node Allocatable computation: Here is an example to illustrate Node Allocatable computation:
* Node has `32Gi` of `memory`, `16 CPUs` and `100Gi` of `Storage` * Node has `32Gi` of `memory`, `16 CPUs` and `100Gi` of `Storage`
* `--kube-reserved` is set to `cpu=1,memory=2Gi,storage=1Gi` * `--kube-reserved` is set to `cpu=1,memory=2Gi,ephemeral-storage=1Gi`
* `--system-reserved` is set to `cpu=500m,memory=1Gi,storage=1Gi` * `--system-reserved` is set to `cpu=500m,memory=1Gi,ephemeral-storage=1Gi`
* `--eviction-hard` is set to `memory.available<500Mi,nodefs.available<10%` * `--eviction-hard` is set to `memory.available<500Mi,nodefs.available<10%`
Under this scenario, `Allocatable` will be `14.5 CPUs`, `28.5Gi` of memory and Under this scenario, `Allocatable` will be `14.5 CPUs`, `28.5Gi` of memory and