H3C UIS Manager

Configuration Cautions and Guidelines

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Document version: 5W100-20210615

Contents

H3C UIS configuration cautions and guidelines· 1

Web-based configuration cautions and guidelines· 1

About Web-based configuration cautions and guidelines· 1

System·· 1

Critical: Connecting to the database on UIS· 1

Major: Installing third-party software· 1

Critical: Changing the shared file system heartbeat network· 1

Major: Mapping a shared storage pool on UIS to a host or VM on another platform. 2

Critical: Reinstalling UIS on a host 2

VM management 2

Major: Powering off a VM·· 2

Critical: Deleting a VM·· 2

Minor: Operating VMs in bulk· 3

Major: Migrating storage for an online VM·· 3

Major: Repairing storage volumes for a VM·· 3

Major: Moving storage volumes in bulk· 4

Major: Editing a VM in a protection group· 4

Minor: Installing a heterogeneous migration client for a VM·· 4

Minor: Editing permissions for resources· 4

Host management 5

Critical: Deleting a host 5

Critical: Shutting down a host when the host is in abnormal state· 5

Critical: Restarting a host when the host is in abnormal state· 5

Major: Importing VMs· 6

Critical: Changing the management network IP for a host 6

Critical: Suspending a vSwitch· 6

Critical: Editing a vSwitch· 6

Minor: Suspending a storage pool 7

Critical: Deleting a storage pool 7

Critical: Formatting a shared file system·· 7

Storage management 7

Major: Deleting a disconnected monitor node· 7

Major: Deleting a monitor node· 8

Minor: Setting the number of replicas to 2 for a storage pool 8

Major: Editing NTP settings· 8

Major: Creating a storage volume larger than the available capacity of a storage pool 9

Major: Expanding a storage volume to be larger than the available capacity of a storage pool 9

Critical: Destroying a storage volume· 9

Critical: Removing a service host from a service host group. 9

Critical: Shutting down the port of a storage front-end NIC· 10

Critical: Editing iSCSI HA· 10

Critical: Disabling iSCSI HA· 10

Critical: Removing a storage volume from a service host group· 11

Minor: Deleting an asynchronous remote replication pair 11

Major: Synchronizing an asynchronous remote replication pair 11

Major: Splitting an asynchronous remote replication pair 11

Critical: Performing a primary/secondary switchover for an asynchronous remote replication pair 12

Critical: Disabling secondary block device protection for an asynchronous remote replication pair 12

CLI-based configuration cautions and guidelines· 1

About CLI-based configuration cautions and guidelines· 1

CLI-based configuration cautions and guidelines· 1

H3C UIS configuration cautions and guidelines

This document contains information that if not or followed can result in severe or undesirable impact on the system or services.

Only trained and qualified personnel are allowed to do the configuration tasks described in this guide.

Before you configure your device, read the information in this document carefully. This document uses the following alert levels to tag information depending on their impact on services:

·     Critical—An alert that calls attention to important information that if not understood or followed can result in system unavailability or service interruption.

·     Major—An alert that calls attention to important information that if not understood or followed can result in unavailability of most functions or services.

·     Minor—An alert that calls attention to important information that if not understood or followed can result in unavailability of some functions without impacting ongoing services.

Web-based configuration cautions and guidelines

About Web-based configuration cautions and guidelines

The following information describes the Web-based tasks that are critical to system functionality and service availability. Only trained and qualified personnel are allowed to do these configuration tasks. If these tasks are not correctly performed, issues such as system shutdown, system reboot, service interruption, service malfunctioning, and deletion of configuration or important files might occur. These issues might cause inaccessibility of the system or services, or cause unexpected logoff of users.

Before you perform a critical task, read the information in this document carefully.

System

Critical: Connecting to the database on UIS

Procedure

Log in to the database from the CLI or use third-party database client software to connect to the database.

Impact

A misoperation might cause database corruption and adversely impact the data-related services running in the system.

Guidelines

Do not perform this operation.

Major: Installing third-party software

Procedure

Install non-H3C approved third-party software from the CLI of a host or replace the software provided with UIS with non-H3C approved third-party software.

Impact

This operation might cause unpredictable reliability or compatibility issues.

Guidelines

Do not perform this operation.

Critical: Changing the shared file system heartbeat network

Procedure

Change the shared file system heartbeat network to a non-default network.

Impact

This operation might cause the shared file system to restart because of a fencing event and adversely impact upper layer services.

Guidelines

Before you perform this operation, shut down all VMs in the cluster and suspend the shared file system.

Major: Mapping a shared storage pool on UIS to a host or VM on another platform.

Procedure

Map a shared storage pool on UIS to a host or VM on another platform.

Impact

This operation will cause storage data conflict and might cause data corruption or loss.

Guidelines

Do not perform this operation.

Critical: Reinstalling UIS on a host

Procedure

Reinstall UIS on a host.

Impact

This operation might adversely impact services running on other hosts in the cluster.

Guidelines

Before you perform this operation, remove the host from the cluster.

VM management

Major: Powering off a VM

Procedure

Click Power Off on the VM management page to power off a VM.

Impact

This operation might cause guest OS failure.

Guidelines

Shut down the VM from its guest OS.

Critical: Deleting a VM

Procedure

Delete a VM by formatting the disk and deleting data files.

Impact

·     This operation might cause service anomaly.

·     Data files for a VM are permanently deleted on deletion of the VM and they cannot be restored.

·     While the system formats the disk and deletes the data files, storage performance and service might degrade and service issues might occur.

Guidelines

Perform this operation with caution.

·     Before you perform this operation, make sure the VM is not in use, and will not be used any more.

·     Shut down the VM if the VM is running.

·     As a best practice, do not select the formatting the disk and deleting data files option for non-sensitive data. If you have to select this option, make sure the data files will not be used any more.

Minor: Operating VMs in bulk

Procedure

Operate VMs in bulk, for example, starting, restarting, and migrating VMs.

Impact

Bulk VM operations are resources intensive and can degrade host performance.

Guidelines

Perform this operation when no services are running on VMs.

Major: Migrating storage for an online VM

Procedure

Migrate VM storage while a VM is online.

Impact

·     This operation will rate limit disk I/O and might degrade service performance or cause other service issues.

·     If VM storage migration has not finished before the migration timer expires, the system will suspend the VM. Services running on the VM will become unavailable.

Guidelines

Perform this operation while the service running on the VM is idle.

Major: Repairing storage volumes for a VM

Procedure

Repair the storage volumes and the file system attached to a VM when the VM fails to start because of storage volume errors.

Impact

This operation might cause disk data loss.

Guidelines

Contact technical support to repair the storage volumes.

Major: Moving storage volumes in bulk

Procedure

Move storage volumes in bulk.

Impact

This operation might cause VM data loss.

Guidelines

Do not move storage volumes in bulk when a VM backup, VM clone, VM snapshot, VM deployment, or DRX task is in progress.

Major: Editing a VM in a protection group

Procedure

Edit a VM in a protection group.

Impact

This operation will cause VM startup failure if you run a test recovery or failure recovery task.

Guidelines

Do not edit the configuration of the VMs in protection groups in a production environment, unless necessary. Especially, do not perform hardware operations such as adding a vNIC or disk to the VM. If you must edit a VM in a protection group, remove that VM from the group first. After the configuration takes effect, add the VM to the protection group again.

Minor: Installing a heterogeneous migration client for a VM

Procedure

Install a heterogeneous migration client for a VM.

Impact

This operation might cause compatibility issues between the heterogeneous migration client and the CDP backup software from other vendors.

Guidelines

Before you perform this operation, make sure the source VM is not installed with CDP software from a third-party vendor.

Minor: Editing permissions for resources

Procedure

Assign permissions for system resources, such as cluster, host, and VM for an operator group to another operator group.

Impact

The original operator group will not have the permissions.

Guidelines

Before you perform this operation, verify the permissions of this and the target operator groups.

Host management

Critical: Deleting a host

Procedure

Delete a host from a cluster.

Impact

·     You cannot revoke this operation.

·     Deleting a host from a cluster will delete all VMs running on the host, including VMs that were removed from the host to the recycle bin.

·     Deleting a host will trigger data balancing, and the data on the host will be balanced to other hosts in the cluster.

·     Deleting a host will delete it from both the compute cluster and storage cluster. If the number of monitor nodes in the cluster cannot satisfy the requirements after the deletion, the system will change other non-monitor nodes to monitor nodes.

Guidelines

·     Before you perform this operation, make sure the host will not be used any more or the host is faulty and cannot be restored.

·     Before you perform this operation, disable cluster HA, suspend and then delete the shared storage pool, and remove the mapping between the host and the shared storage pool.

·     For a host that has been deleted from the cluster, reinstall CVK for the host, and then add the host to the cluster.

·     If the deletion operation fails, and the system prompts a connection error, reconnect the host to the system and then delete the host.

Critical: Shutting down a host when the host is in abnormal state

Procedure

Shut down a host when the host is in abnormal state.

Impact

This operation might cause host startup failure.

Guidelines

Please contact technical support.

Critical: Restarting a host when the host is in abnormal state

Procedure

Restart a host when the host is in abnormal state.

Impact

This operation might cause host startup failure.

Guidelines

Please contact technical support.

Major: Importing VMs

Procedure

Restore VMs by importing VMs when the VMs are running correctly.

Impact

This operation might cause VM data loss.

Guidelines

As a best practice, do not perform this operation when VMs are running correctly.

Critical: Changing the management network IP for a host

Procedure

Change the management network IP for a host.

Impact

This operation might cause connectivity issues between the host and the cluster network and might cause the host to restart because of a fencing event and affect services.

Guidelines

Before you perform this operation, stop all services on the host, suspend and delete the shared storage pool, and delete the host from the cluster. For more information, contact technical support.

Critical: Suspending a vSwitch

Procedure

Suspend a vSwitch.

Impact

This operation will cause service interruption.

Guidelines

Before you perform this operation, make sure the vSwitch is not in use.

Critical: Editing a vSwitch

Procedure

Edit vSwitch settings such as VLAN ID, physical interface, and IP address.

Impact

This operation might cause network connectivity issues and service interruption.

Guidelines

Before you perform this operation, make sure no services are running on the vSwitch and the related settings on the physical switch are also edited.

Minor: Suspending a storage pool

Procedure

Suspend an active storage pool.

Impact

This operation will cause VMs startup failure.

Guidelines

Before you perform this operation, verify that the storage services are not in use, and migrate VMs that you want them to continue operation to anther storage pool.

Critical: Deleting a storage pool

Procedure

Delete a storage pool when it is used by a running VM or other processes.

Impact

This operation will cause unavailability of VMs.

Guidelines

Before you perform this operation, verify that the storage services are not in use, and migrate VMs that you want them to continue operation to anther storage pool.

Critical: Formatting a shared file system

Procedure

Format a shared file system after it has been running for a period of time.

Impact

This operation will clear all files in the shared file system and clear all data.

Guidelines

Before you perform this operation, and make sure the data in the shared file system will not be used any more.

Storage management

Major: Deleting a disconnected monitor node

Procedure

Delete a monitor node that is disconnected from UIS due to management network anomaly.

Impact

·     This operation deletes only information about the monitor node from UIS. The configuration, data, and components issued by UIS remain on the monitor node.

·     This operation does not remove the roles other than monitor node, storage node in a cluster for example.

·     To assign the deleted monitor node to a storage cluster again, you must first destroy the node and remove all its roles in a cluster.

Guidelines

Perform this operation only when a monitor node is abnormal and cannot be recovered.

Before you assign the deleted monitor node to a storage cluster again, contact technical support.

Major: Deleting a monitor node

Procedure

Delete a monitor node from a cluster.

Impact

The cluster might become unavailable.

Guidelines

Before you perform this operation, perform the following tasks:

·     Determine the number of monitor nodes based on the condition of the storage cluster.

·     Verify that the monitor node to delete is no longer needed.

Minor: Setting the number of replicas to 2 for a storage pool

Procedure

Use replication for data redundancy and set the number of replicas to 2 during storage pool creation.

Impact

The possibility of data loss is high if the number of replicas is smaller than 3.

Guidelines

For important services and scenarios that require high reliability, set the number of replicas to 3 or more if the data redundancy policy is replication.

Major: Editing NTP settings

Procedure

Edit NTP settings.

Impact

·     Disabling NTP synchronization might cause the time skew between storage nodes to increase and eventually interrupt services.

·     Changing the NTP server might cause the storage cluster to malfunction if a large time skew exists between the new NTP server and the cluster.

Guidelines

Perform this operation with caution.

·     As a best practice, enable NTP synchronization.

·     Make sure only a small time skew exists between the new NTP server and the cluster.

Major: Creating a storage volume larger than the available capacity of a storage pool

Procedure

Create a storage volume so the total capacity of storage volumes is larger than the available capacity of a thin provisioned block storage pool.

Impact

The storage volumes in a thin provisioned storage pool share the capacity of the storage pool. UIS allows overcommitment as UIS assigns storage space dynamically to optimize storage usage. However, when the storage traffic is large, this operation might cause storage service interruption.

Guidelines

Plan storage volumes sizes based on storage service requirements.

Major: Expanding a storage volume to be larger than the available capacity of a storage pool

Procedure

Expand a storage volume so the total capacity of storage volumes is larger than the available capacity of a thin provisioned block storage pool.

Impact

The storage volumes in a thin provisioned storage pool share the capacity of the storage pool. UIS allows overcommitment as UIS assigns storage space dynamically to optimize storage usage. However, when the storage traffic is large, this operation might cause storage service interruption.

Guidelines

Plan storage volumes sizes based on storage service requirements.

Critical: Destroying a storage volume

Procedure

Destroy a storage volume when deleting it.

Impact

This operation deletes a storage volume and its data completely, and the data cannot be recovered.

Guidelines

Make sure the storage volume is no longer needed.

Critical: Removing a service host from a service host group.

Procedure

Remove a service host from a service host group.

Impact

The removed service host cannot access the mapped storage volumes of the service host group.

Guidelines

·     Make sure services of the service host have been stopped on the mapped storage volumes of the service host group.

·     Make sure the service host is no longer needed.

Critical: Shutting down the port of a storage front-end NIC

Procedure

Shut down the port of a storage front-end NIC.

Impact

This operation interrupts the services conveyed by the shutdown port.

Guidelines

·     Make sure services have been stopped on the port to shut down.

·     Make sure the port is no longer needed.

Critical: Editing iSCSI HA

Procedure

Edit iSCSI HA settings.

Impact

This operation will cause the HA IP address of iSCSI block storage to be unavailable. Service hosts cannot access the block storage resources of the cluster at the HA IP address.

Guidelines

·     Stop the services provided by the iSCSI HA group.

·     To prevent service interruption, configure routing to make sure the nodes in the same iSCSI HA group can reach one another at Layer 3.

·     Verify that the iSCSI HA group is no longer needed.

Critical: Disabling iSCSI HA

Procedure

Disable iSCSI HA.

Impact

This operation will cause the HA IP address of iSCSI block storage to be unavailable. Service hosts cannot access the block storage resources of the cluster at the HA IP address.

Guidelines

·     Stop the services provided by the iSCSI HA group.

·     Verify that the iSCSI HA group is no longer needed.

Critical: Removing a storage volume from a service host group

Procedure

Remove a storage volume from a service host group.

Impact

This operation will disable the service host group from accessing the storage volume and cause service interruption.

Guidelines

·     Stop the services provided by the storage volume to remove.

·     Verify that the storage volume is no longer needed.

Minor: Deleting an asynchronous remote replication pair

Procedure

Delete an asynchronous remote replication pair.

Impact

This operation will delete the replication relationship between the primary and secondary storage volumes. This operation cannot be revoked.

Guidelines

Verify that the asynchronous remote replication pair is no longer needed.

Major: Synchronizing an asynchronous remote replication pair

Procedure

Synchronize an asynchronous remote replication pair.

Impact

This operation will overwrite the data of the secondary storage volume with the data of the primary storage volume.

Guidelines

Verify that the asynchronous remote replication pair to synchronize is correct and the data of the secondary storage volume can be overwritten.

Major: Splitting an asynchronous remote replication pair

Procedure

Split an asynchronous remote replication pair.

Impact

This operation will stop the replication between the primary and secondary storage volumes and cause data inconsistency.

Guidelines

Verify that the asynchronous remote replication pair to split is correct and data synchronization is not needed between the primary and secondary storage volumes. To resume replication between the primary and secondary storage volumes, synchronize the asynchronous remote replication pair.

Critical: Performing a primary/secondary switchover for an asynchronous remote replication pair

Procedure

Perform a primary/secondary switchover for an asynchronous remote replication pair.

Impact

This operation will switch primary and secondary storage volumes. A misoperation might cause the data of the original primary storage volume to be overwritten by the data of the original secondary storage volume

Guidelines

Verify that the asynchronous remote replication pair is correct and a role switchover is required.

Critical: Disabling secondary block device protection for an asynchronous remote replication pair

Procedure

Disable secondary block device protection for an asynchronous remote replication pair.

Impact

This operation will place the secondary storage volume in read and write state. If data is written to the secondary storage volume, the service data synchronized from the primary storage volume will be overwritten, and data inconsistency will occur between the primary and secondary storage volumes.

Guidelines

Verify that secondary block device protection is no longer needed for the asynchronous remote replication pair.

 

CLI-based configuration cautions and guidelines

About CLI-based configuration cautions and guidelines

The following information describes the CLI-based tasks that are critical to system functionality and service availability.

Only trained and qualified personnel are allowed to do the configuration tasks described in this guide.

If these tasks are not correctly performed, issues such as system shutdown, system reboot, service interruption, service malfunctioning, and deletion of configuration or important files might occur. These issues might cause inaccessibility of the system or services, or cause unexpected logoff of users.

Before you configure your device, read the information in this document carefully.

CLI-based configuration cautions and guidelines

Operation	Procedure		Impact	Guidelines
System management
Destroying a cluster	Use the destroy_all command to destroy a cluster.		This command will uninstall the UIS components from all cluster nodes and clear all UIS data and configuration on these nodes. Once deleted, the data and configuration cannot be restored.	Use this command with caution. Before executing this command, verify that the current cluster is the target cluster to delete and the cluster is no longer required.
Destroying a node pool	Use the destroy command to destroy a node pool.		This command will uninstall the UIS components from all nodes in the node pool to which the current node belongs and clear all UIS data and configuration on these nodes. Once deleted, the data and configuration cannot be restored.	Use this command with caution. As a best practice, do not execute this command unless the node pool anomaly cannot be resolved. Before adding a deleted node pool back to the storage cluster again, you must manually destroy the node pool.
Destroying a host	Use the destroy -hosts ip-address command to destroy a host.		This command will uninstall the UIS components from the specified node and clear all UIS data and configuration on the node. Once deleted, the data and configuration cannot be restored.	Use this command with caution. As a best practice, do not execute this command unless the host anomaly cannot be resolved. Before adding a deleted host back to the storage cluster again, you must remove all cluster node roles from the host and manually destroy the host.
Editing host name	Use the vi /etc/hosts, vim /etc/hosts, or hostnamectl command to edit the name of a host.		After you execute this command, the configuration file that contains the original host name will become invalid and services on the host will be interrupted.	Do not execute these commands.
Changing the system time of a node	Use the date -s command to change the system time of a node.		This command might cause cluster errors if the time between nodes in the cluster is out of synchronization.	Use this command with caution. Make sure you are fully aware of the impact of this command.
Restarting or shutting down a node	Use the following commands to restart, shut down, or power off a node: ·     reboot ·     shutdown ·     poweroff		These commands will cause unavailability of the node and interrupt services running on the node.	Use these commands with caution. Make sure you are fully aware of the impact of these commands. To restart or shut down a node, access the console of the node from HDM.
Stopping a process	Use the kill or killall command to stop a process.		Incorrect use of this command can cause feature or service anomaly.	Use these commands with caution. Make sure you are fully aware of the impact of these commands.
Stopping the crond daemon	Use either of the following commands to stop the crond daemon: ·     service crond stop ·     systemctl stop crond.service		The crond daemon executes scheduled commands or scripts in Linux. Stopping the daemon will cause cluster errors.	Do not execute these commands.
Restarting the libvirt service	Use either of the following commands to restart the libvirt service: ·     service libvirt-bin restart ·     systemctl restart libvirtd.service		These commands will create ghost VMs and damage the disks on the corresponding real VMs if VMs with a Chinese name exist on a host.	Use these commands with caution. Execute the virsh list --all command at the CLI of the host to verify that no VMs with a Chinese name exist on the host.
Freeing up storage space	Use the fstrim command to free up storage space.		This command will cause high storage latency, because freeing up storage space requires storage I/O operations.	Use this command with caution. As a best practice, execute this command when no services are running in the system. To obtain help, contact technical support.
Downloading a script	Use the wget command to download a script.		Unpredictable issues might occur if you download an unknown script.	Before executing this command, make sure the script is secure and reliable.
Running an unknown script	N/A		Unpredictable issues might occur if you download an unknown script.	Use this command with caution. Before executing this command, verify that the script is secure and reliable and make sure you are fully aware of the impact of the operation.
Changing the system directory or boot file	Use the chroot command to change the system directory or boot file.		This command might cause the host to malfunction.	Do not execute this command.
Storage management
Running a performance test	Use the fio command to run a storage performance test.		Incorrect use of this command might damage the disks or the shared file system.	As a best practice, run a performance test before service deployment. If you have to run a performance test after service deployment, contact technical support.
Managing storage	Use the fsmcli command to manage the storage.		Incorrect use of this command might cause service anomaly.	Do not execute this command.
Disk management
Formatting a disk	Use the mkfs command to format a disk.	Incorrect use of this command might cause disk data loss.		Do not execute this command.
Rebuilding a partition	Use the fdisk or parted command to rebuild a partition.	Incorrect use of this command might clear a partition.		Use this command with caution. Make sure the host does not have running services before you execute this command. To view all disk partitions, execute the fdisk –l command.
Deploying OSDs	Use the following commands to deploy OSDs: ·     ceph-disk prepare /dev/sd* ·     ceph-disk activate /dev/sd*	Executing these commands might affect the original OSDs in the cluster and cause service anomaly.		OSD settings will be automatically configured when you operate disks on the cluster management interface. If necessary, execute these commands in accordance with the maintenance guide.
Clearing OSDs	Use the following commands to clear OSDs: ·     ceph osd out osd-id ·     ceph osd down osd-id ·     ceph osd rm osd-id ·     ceph osd crush remove osd. osd-id ·     ceph auth del osd. osd-id	A misoperation might cause cluster errors.		OSD settings will be automatically configured when you operate disks on the cluster management interface. If necessary, execute these commands in accordance with the maintenance guide.
Unmounting a disk	Use the umount command to unmount a disk.	Incorrect use of this command might corrupt the file system and data on a disk and cause service anomaly or data loss.		Do not execute this command.
Upgrade management
Performing an offline cluster upgrade	Use the ./uis_upgrade.sh offline command on the UIS management node to perform an offline cluster upgrade.	Once upgraded, the cluster cannot be rolled back.		Execute this command in accordance with the upgrade guide.
Performing an online cluster upgrade	Use the ./uis_upgrade.sh online command on the UIS management node to perform an online cluster upgrade.	Once upgraded, the cluster cannot be rolled back.		Execute this command in accordance with the upgrade guide.
VM management
Operating VMs	Use virsh commands to operate VMs.		Use execution commands such as virsh destroy, virsh snapshot, virsh undefine, and virsh migrate with caution. Incorrect use of these commands might adversely impact services. This caution is not true for query commands such as virsh list, virshpool-list, virsh domjobinfo, domblklist, and vncdisplay.	As a best practice, operate VMs on UIS.
Operating VM disks	Use qemu-img commands to operate VM disks.		Except for query commands such as qemu-img info, execute the qemu-img commands such as qemu-img check, rebase, create, and snapshot with caution. Executing these commands while a VM is running will corrupt its disk files.	Use these commands with caution. Shut down the VM before you execute these commands.
Network configuration
Editing network settings for a node	Use the following commands to edit network settings for a node: ·     ifdown ·     ifup ·     ifconfig down ·     ifconfig up ·     route		These commands will cause network errors on a node and eventually cause cluster errors if your network configuration is incorrect.	Use these command with caution. Carefully plan your network before executing these commands and make sure you are fully aware of the impact of these commands.
Deleting a vSwitch or vNetwork	Use the following commands to delete a vSwitch or a vNetwork: ·     ovs-vsctl del-br ·     ovs-vsctl del-port		Incorrectly deleting a vSwitch or vNetwork will cause network errors.	Use the commands with caution. Make sure the target vSwitch or vNetwork can be deleted and delete them from UIS.
Adding a port to a vSwitch	Use the ovs-vsctl add-port command to add a port to a vSwitch.		This command can cause loops if multiple ports are added without being aggregated.	As a best practice, edit vSwitch settings on UIS and verify the network settings for the vSwitch.
Adding or deleting a flow for a vSwitch	Use the following commands to add or delete a flow for a vSwitch: ·     ovs-ofctl add-flow ·     ovs-ofctl del-flows		Incorrect use of this command might cause service interruption and loops.	As a best practice, edit a flow by editing the ACL or vFirewall settings for the VMs on UIS. To edit a flow from the CLI, contact technical support.
File management
Changing the group ownership of a file or directory	Use the chgrp command to change the group ownership of a file or directory.		A misoperation might cause cluster errors.	Use this command with caution. Make sure you are fully aware of the impact of this command before executing this command.
Changing the ownership of files or directories	Use the chown command to change the ownership of files or directories.		A misoperation might cause cluster errors.	Use this command with caution. Make sure you are fully aware of the impact of this command before executing this command.
Changing the access permissions of files or directories	Use the chmod command to change the access permissions of files or directories.		A misoperation will cause cluster errors.	Use this command with caution. Make sure you are fully aware of the impact of this command before executing this command.
Removing a directory and its contents recursively	Use the rm –rf command to remove a directory and its contents recursively.		A misoperation might cause important file or data to be mistakenly deleted.	Use this command with caution. Verify the directory and its contents before executing this command.
Forcibly copying or moving a file	Use the following commands to copy, move, or create a file: ·     cp –rf ·     mv –f		Executing these commands will forcibly copy or move a file to a new directory without any warning or notification.	Use these commands with caution. Make sure the file to copy or move has a different name than the existing files in the new directory.
Operating a file descriptor	Use the echo or dd command to operate a file descriptor.		These commands will edit the files mapped from a disk to the /dev/ directory and might corrupt the file system and data on the disk.	Do not use these commands.
Editing a file	Use the vi or vim command to edit a file.		A misoperation might cause unpredictable issues.	Use these commands with caution. Make sure you are fully aware of the impact of these commands. Do not edit system files.
User management
Deleting a user account	Use the userdel command to delete a user account.		Incorrect use of this command might cause service anomaly.	Do not use this command.