Scenario

You can mount cloud storage volumes to your containers and use these volumes as local directories.

This section describes how to set mount options when mounting SFS and OBS volumes. You can set mount options in a PV and bind the PV to a PVC. Alternatively, set mount options in a StorageClass and use the StorageClass to create a PVC. In this way, PVs can be dynamically created and inherit mount options configured in the StorageClass by default.

SFS Volume Mount Options

The everest add-on in CCE presets the options described in Table 1 for mounting SFS volumes. You can set other mount options if needed. For details, see Mounting an NFS File System to ECSs (Linux).

**Table 1** Preset mount options for SFS volumes
Option	Description
vers=3	File system version. Currently, only NFSv3 is supported, Value: 3
nolock	Whether to lock files on the server using the NLM protocol. If nolock is selected, the lock is valid for applications on one host. For applications on another host, the lock is invalid.
timeo=600	Waiting time before the NFS client retransmits a request. The unit is 0.1 seconds. Recommended value: 600
hard/soft	Mounting mode. hard: If the NFS request times out, the client keeps resending the request until the request is successful. soft: If the NFS request times out, the client returns an error to the invoking program. The default value is hard.

OBS Volume Mount Options

When mounting file storage, the everest add-on presets the options described in Table 2 and Table 3 by default. The options in Table 2 are mandatory.

**Table 2** Mandatory mount options configured by default
Option	Description
use_ino	If enabled, obsfs allocates the inode number. Enabled by default in read/write mode.
big_writes	If configured, the maximum size of the cache can be modified.
nonempty	Allows non-empty mount paths.
allow_other	Allows other users to access the parallel file system.
no_check_certificate	Disables server certificate verification.
enable_noobj_cache	Enables cache entries for objects that do not exist, which can improve performance. Enabled by default in object bucket read/write mode. This option is no longer set by default since everest 1.2.40.
sigv2	Specifies the signature version. Used by default in object buckets.

**Table 3** Optional mount options configured by default
Option	Description
max_write=131072	If specified, obsfs allocates the inode number. Enabled by default in read/write mode.
ssl_verify_hostname=0	Disables verifying the SSL certificate based on the host name.
max_background=100	Allows setting the maximum number of waiting requests in the background. Used by default in parallel file systems.
public_bucket=1	If set to 1, public buckets are mounted anonymously. Enabled by default in object bucket read/write mode.

You can log in to the node to which the pod is scheduled and view all mount options used for mounting the OBS volume in the process details.

Object bucket: ps -ef | grep s3fs

root     22142     1  0 Jun03 ?        00:00:00 /usr/bin/s3fs pvc-82fe2cbe-3838-43a2-8afb-f994e402fb9d /mnt/paas/kubernetes/kubelet/pods/0b13ff68-4c8e-4a1c-b15c-724fd4d64389/volumes/kubernetes.io~csi/pvc-82fe2cbe-3838-43a2-8afb-f994e402fb9d/mount -o url=https://{{endpoint}}:443 -o endpoint=xxxxxx -o passwd_file=/opt/everest-host-connector/1622707954357702943_obstmpcred/pvc-82fe2cbe-3838-43a2-8afb-f994e402fb9d -o nonempty -o big_writes -o enable_noobj_cache -o sigv2 -o allow_other -o no_check_certificate -o ssl_verify_hostname=0 -o max_write=131072 -o multipart_size=20 -o umask=0

Parallel file system: ps -ef | grep obsfs

root      1355     1  0 Jun03 ?        00:03:16 /usr/bin/obsfs pvc-86720bb9-5aa8-4cde-9231-5253994f8468 /mnt/paas/kubernetes/kubelet/pods/c959a91d-eced-4b41-91c6-96cbd65324f9/volumes/kubernetes.io~csi/pvc-86720bb9-5aa8-4cde-9231-5253994f8468/mount -o url=https://{{endpoint}}:443 -o endpoint=xxxxxx -o passwd_file=/opt/everest-host-connector/1622714415305160399_obstmpcred/pvc-86720bb9-5aa8-4cde-9231-5253994f8468 -o allow_other -o nonempty -o big_writes -o use_ino -o no_check_certificate -o ssl_verify_hostname=0 -o umask=0027 -o max_write=131072 -o max_background=100 -o uid=10000 -o gid=10000

Prerequisites

The everest add-on version must be 1.2.8 or later.
The add-on identifies the mount options and transfers them to the underlying storage resources, which determine whether the specified options are valid.

Notes and Constraints

Mount options cannot be configured for secure containers.

Setting Mount Options in a PV

You can use the mountOptions field to set mount options in a PV. The options you can configure in mountOptions are listed in SFS Volume Mount Options and OBS Volume Mount Options.

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv-obs-example
  annotations:
    pv.kubernetes.io/provisioned-by: everest-csi-provisioner
spec:
  mountOptions:
  - umask=0027
  - uid=10000
  - gid=10000
  accessModes:
  - ReadWriteMany
  capacity:
    storage: 1Gi
  claimRef:
    apiVersion: v1
    kind: PersistentVolumeClaim
    name: pvc-obs-example
    namespace: default
  csi:
    driver: obs.csi.everest.io
    fsType: obsfs
    volumeAttributes:
      everest.io/obs-volume-type: STANDARD
      everest.io/region: eu-de
      storage.kubernetes.io/csiProvisionerIdentity: everest-csi-provisioner
    volumeHandle: obs-normal-static-pv
  persistentVolumeReclaimPolicy: Delete
  storageClassName: csi-obs

After a PV is created, you can create a PVC and bind it to the PV, and then mount the PV to the container in the workload.

Setting Mount Options in a StorageClass

You can use the mountOptions field to set mount options in a StorageClass. The options you can configure in mountOptions are listed in SFS Volume Mount Options and OBS Volume Mount Options.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: csi-obs-mount-option
mountOptions:
- umask=0027
- uid=10000
- gid=10000
parameters:
  csi.storage.k8s.io/csi-driver-name: obs.csi.everest.io
  csi.storage.k8s.io/fstype: s3fs
  everest.io/obs-volume-type: STANDARD
provisioner: everest-csi-provisioner
reclaimPolicy: Delete
volumeBindingMode: Immediate

After the StorageClass is configured, you can use it to create a PVC. By default, the dynamically created PVs inherit the mount options set in the StorageClass.