Expanding the Storage Space

The storage classes that can be expanded for CCE nodes are as follows:

Table 1 Capacity expansion methods

Type

Name

Purpose

Capacity Expansion Method

Node disk

System disk

A disk attached to a node for installing the operating system

Expanding System Disk Capacity

Data disk

A disk that must be attached to a node for the container engine and kubelet

Container storage

Pod container space

The base size of a container, which is, the upper limit of the disk space occupied by each pod (including the storage space occupied by container images)

Expanding the Capacity of a Data Disk Used by Pod (basesize)

PVC

Storage resources mounted to the containers

Expanding a PVC

Expanding System Disk Capacity

EulerOS 2.9 is used as the sample OS. There is only one partition (/dev/vda1) with a capacity of 50 GiB in the system disk /dev/vda, and then 50 GiB is added to the system disk. In this example, the additional 50 GiB is allocated to the existing /dev/vda1 partition.

  1. Expand the capacity of the system disk on the EVS console.
  2. Log in to the node and run the growpart command to check whether growpart has been installed.

    If the tool operation guide is displayed, the growpart has been installed. Otherwise, run the following command to install growpart:

    yum install cloud-utils-growpart

  3. Run the following command to view the total capacity of the system disk /dev/vda:

    fdisk -l

    If the following information is displayed, the total capacity of /dev/vda is 100 GiB.

    [root@test-48162 ~]# fdisk -l
Disk /dev/vda: 100 GiB, 107374182400 bytes, 209715200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x78d88f0b

Device     Boot Start       End   Sectors Size Id Type
/dev/vda1  *     2048 104857566 104855519  50G 83 Linux

Disk /dev/vdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/mapper/vgpaas-dockersys: 90 GiB, 96632569856 bytes, 188735488 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/mapper/vgpaas-kubernetes: 10 GiB, 10733223936 bytes, 20963328 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

  4. Run the following command to check the capacity of the system disk partition /dev/vda1:

    df -TH

    Information similar to the following is displayed:

    [root@test-48162 ~]# df -TH
Filesystem                    Type      Size  Used Avail Use% Mounted on
devtmpfs                      devtmpfs  1.8G     0  1.8G   0% /dev
tmpfs                         tmpfs     1.8G     0  1.8G   0% /dev/shm
tmpfs                         tmpfs     1.8G   13M  1.8G   1% /run
tmpfs                         tmpfs     1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/vda1                     ext4      53G  3.3G   47G   7% /
tmpfs                         tmpfs     1.8G   75M  1.8G   5% /tmp
/dev/mapper/vgpaas-dockersys  ext4       95G  1.3G   89G   2% /var/lib/docker
/dev/mapper/vgpaas-kubernetes ext4       11G   39M   10G   1% /mnt/paas/kubernetes/kubelet
...

  5. Run the following command to extend the partition using growpart:

    growpart System disk Partition number

    The partition number is 1 because there is only one /dev/vda1 partition in the system disk, as shown in the following command:

    growpart /dev/vda 1

    Information similar to the following is displayed:

    CHANGED: partition=1 start=2048 old: size=104855519 end=104857567 new: size=209713119 end=209715167

  6. Run the following command to extend the file system:

    resize2fs Disk partition

    An example command is as follows:

    resize2fs /dev/vda1

    Information similar to the following is displayed:

    resize2fs 1.45.6 (20-Mar-2020)
Filesystem at /dev/vda1 is mounted on /; on-line resizing required
old_desc_blocks = 7, new_desc_blocks = 13
The filesystem on /dev/vda1 is now 26214139 (4k) blocks long.

  7. Run the following command to view the new capacity of the /dev/vda1 partition:

    df -TH

    Information similar to the following is displayed:

    [root@test-48162 ~]# df -TH
Filesystem                    Type      Size  Used Avail Use% Mounted on
devtmpfs                      devtmpfs  1.8G     0  1.8G   0% /dev
tmpfs                         tmpfs     1.8G     0  1.8G   0% /dev/shm
tmpfs                         tmpfs     1.8G   13M  1.8G   1% /run
tmpfs                         tmpfs     1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/vda1                     ext4     106G  3.3G   98G   4% /
tmpfs                         tmpfs     1.8G   75M  1.8G   5% /tmp
/dev/mapper/vgpaas-dockersys  ext4       95G  1.3G   89G   2% /var/lib/docker
/dev/mapper/vgpaas-kubernetes ext4       11G   39M   10G   1% /mnt/paas/kubernetes/kubelet
...

  8. Log in to the CCE console and click the cluster. In the navigation pane, choose Nodes. Click More > Sync Server Data in the row containing the target node.

Expanding the Capacity of a Data Disk Used by Container Engines

CCE divides the data disk space for two parts by default. One part is used to store the Docker/containerd working directories, container images, and image metadata. The other is reserved for kubelet and emptyDir volumes. The available container engine space affects image pulls and container startup and running. This section uses Docker as an example to describe how to expand the container engine capacity.

  1. Expand the capacity of the data disk on the EVS console.
  2. Log in to the CCE console and click the cluster. In the navigation pane, choose Nodes. Click More > Sync Server Data in the row containing the target node.
  3. Log in to the target node.
  4. Run the lsblk command to check the block device information of the node.

    A data disk is divided depending on the container storage Rootfs:

    • Overlayfs: No independent thin pool is allocated. Image data is stored in the dockersys disk.
      # lsblk
NAME                MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
vda                   8:0    0   50G  0 disk 
└─vda1                8:1    0   50G  0 part /
vdb                   8:16   0  200G  0 disk 
├─vgpaas-dockersys  253:0    0   90G  0 lvm  /var/lib/docker               # Space used by the container engine
└─vgpaas-kubernetes 253:1    0   10G  0 lvm  /mnt/paas/kubernetes/kubelet  # Space used by Kubernetes

      Run the following commands on the node to add the new disk capacity to the dockersys disk:

      pvresize /dev/vdb 
lvextend -l+100%FREE -n vgpaas/dockersys
resize2fs /dev/vgpaas/dockersys
    • Devicemapper: A thin pool is allocated to store image data.
      # lsblk
NAME                                MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
vda                                   8:0    0   50G  0 disk 
└─vda1                                8:1    0   50G  0 part /
vdb                                   8:16   0  200G  0 disk 
├─vgpaas-dockersys                  253:0    0   18G  0 lvm  /var/lib/docker    
├─vgpaas-thinpool_tmeta             253:1    0    3G  0 lvm                   
│ └─vgpaas-thinpool                 253:3    0   67G  0 lvm                   # Space used by thinpool
│   ...
├─vgpaas-thinpool_tdata             253:2    0   67G  0 lvm  
│ └─vgpaas-thinpool                 253:3    0   67G  0 lvm  
│   ...
└─vgpaas-kubernetes                 253:4    0   10G  0 lvm  /mnt/paas/kubernetes/kubelet
      • Run the following commands on the node to add the new disk capacity to the thinpool disk:
        pvresize /dev/vdb 
lvextend -l+100%FREE -n vgpaas/thinpool
      • Run the following commands on the node to add the new disk capacity to the dockersys disk:
        pvresize /dev/vdb 
lvextend -l+100%FREE -n vgpaas/dockersys
resize2fs /dev/vgpaas/dockersys

Expanding the Capacity of a Data Disk Used by kubelet

CCE divides the data disk space for container engines and pods. The container engine space stores the Docker/containerd working directories, container images, and image metadata. The other is reserved for kubelet and emptyDir volumes. To expand the kubelet space, perform the following steps:

  1. Expand the capacity of the data disk on the EVS console.
  2. Log in to the CCE console and click the cluster. In the navigation pane, choose Nodes. Click More > Sync Server Data in the row containing the target node.
  3. Log in to the target node.
  4. Run lsblk to view the block device information of the node.

    # lsblk
NAME                MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
vda                   8:0    0   50G  0 disk 
└─vda1                8:1    0   50G  0 part /
vdb                   8:16   0  200G  0 disk 
├─vgpaas-dockersys  253:0    0   90G  0 lvm  /var/lib/docker               # Space used by the container engine
└─vgpaas-kubernetes 253:1    0   10G  0 lvm  /mnt/paas/kubernetes/kubelet  # Space used by Kubernetes

  5. Run the following commands on the node to add the new disk capacity to the Kubernetes disk:

    pvresize /dev/vdb
lvextend -l+100%FREE -n vgpaas/kubernetes
resize2fs /dev/vgpaas/kubernetes

Expanding the Capacity of a Data Disk Used by Pod (basesize)

  1. Log in to the CCE console and click the cluster name to access the cluster console.
  2. Choose Nodes from the navigation pane.
  3. Click the Nodes tab, locate the row containing the target node, and choose More > Reset Node in the Operation column.

    Resetting a node may make unavailable the node-specific resources (such as local storage and workloads scheduled to this node). Exercise caution when performing this operation to avoid impact on running services.

  4. Click Yes.
  5. Reconfigure node parameters.

    If you need to adjust the container storage space, pay attention to the following configurations:

    Storage Settings: Click Expand next to the data disk to set the following parameters:

    Space Allocation for Pods: indicates the base size of a pod. It is the maximum size that a workload's pods (including the container images) can grow to in the disk space. Proper settings can prevent pods from taking all the disk space available and avoid service exceptions. It is recommended that the value is less than or equal to 80% of the container engine space. This parameter is related to the node OS and container storage rootfs and is not supported in some scenarios. For details, see Data Disk Space Allocation.

  6. After the node is reset, log in to the node and run the following command to access the container and check whether the container storage capacity has been expanded:

    docker exec -it container_id /bin/sh or kubectl exec -it container_id /bin/sh

    df -h

Expanding a PVC

Cloud storage:

Parent topic: Storage