Manage instance

The following describes how to manage instances in the Virtual Machine service.

View instance list and basic information

You can view the list of running instances and their basic information.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.
2. In the Instance menu, check the list of currently running instances.

   Category	Description
   Name	User-defined instance name
   ID	Unique ID of the instance
   Status	Current status of the instance - See Billing by instance state
   Type	Server type of the instance
   Image	Image installed on the instance
   Primary private IP	Private IP address assigned to the primary network interface of the instance
   Primary public IP	Public IP address that the user connected to the primary network interface of the instance
   Availability zone	Availability zone where the instance is created
   Created at	Date when the instance was created

Run and manage instance

You can run various features by clicking the [⋮] button on the right side of the instance list.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.

2. In the Instance menu, click the [⋮] button of the instance, then select the feature to run.

   Instance more

   Feature	Description	Instance status after execution
   Start	Start the instance (start) - Change an instance in the Stopped or Shelved_offloaded state to the Active state	Active
   Stop	Stop the instance (stop)	Stopped
   Reboot	Reboot the instance (soft reboot)	Active
   Hard reboot	Force reboot the instance (hard reboot)	Active
   Shelve	Shelve the instance (shelve)	Shelved_offloaded
   Edit information	Modify the instance name and description	-
   Change type	Change the instance type (resize) - Type change is available only in the Stopped state	-
   Attach network interface	Attach a secondary network interface to the instance	-
   Detach network interface	Detach a secondary network interface connected to the instance	-
   Modify security group	Modify the security group applied to the instance	-
   Connect public IP	Connect a public IP to the instance - Available only to project administrators	-
   Disconnect public IP	Disconnect the public IP from the instance - Available only to project administrators	-
   Modify allowed packet source IPs	Modify IP addresses or CIDRs allowed for packet transmission from the network interface connected to the instance - Up to 10 additional entries can be added 💡 If a specific IP or CIDR is added, the network interface allows transmission of packets whose IP addresses fall within that IP address or CIDR range.	-
   Connect to instance	Provide guidance for connecting to the instance through SSH or RDP	-
   View system log	View system logs stored in the instance - Data containing all records of the audited system, showing progress such as program operation status - Not supported for instances with Windows OS installed	-
   Create image	Create an image from the root volume of the instance - You can create an instance again from the backed-up image 💡 You can create an image when the instance is in the Stopped or Active state, but for data consistency, creating an image in the Stopped state is recommended.	-
   Delete	Completely terminate and release the instance	-

View instance details

You can view detailed information such as instance details, networks, security, volumes, task logs, and monitoring information connected to the instance.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.

2. In the Instance menu, select the instance for which you want to view detailed information.

3. Check the detailed information in each tab.

   Details

   You can check the detailed information of the instance.

   Category	Description
   Name	User-defined instance name
   ID	Unique ID (UUID) of the instance
   Description	Description of the instance
   Status	Current status of the instance
   Availability zone	Availability zone where the instance is located
   Host name	Host name automatically created in the private IP format - Host name assigned in the host-{PRIVATE_IP} format
   Instance type	Instance type selected when creating the instance
   Image	Image name of the instance
   vCPU	Number of CPUs according to the instance type
   Memory	Memory size according to the instance type
   Volume	Disk capacity applied to the instance
   Key pair	Key pair of the instance
   CPU multithreading	Whether the CPU multithreading feature is enabled
   Creator UUID	User who created the instance
   Created at	Creation date and time of the instance (elapsed time since creation)

   Network

   You can check the detailed network information and network interface information of the instance.

   Category	Description
   Interface name	Name assigned to the network interface
   Interface ID	Unique UUID of the network interface
   Connection status	Connection status of the network interface - In Use: State connected to a resource - Available: State not connected to a resource
   Private IP	Private IP assigned to the network interface
   Public IP	Public IP connected to the network interface
   Availability zone	Availability zone where the network interface is created
   VPC name	VPC name where the network interface is created
   VPC ID	Unique UUID of the VPC where the network interface is created
   Subnet name	Subnet name where the network interface is created
   Subnet ID	Unique UUID of the subnet where the network interface is created
   Allowed packet source IPs	Display added IP addresses and CIDR entries as allowed packet source IPs
   [⋮] button	- Modify allowed packet source IPs: Add or delete IP addresses or CIDRs allowed for packet transmission on the selected network interface - Detach network interface: Detach the selected network interface from the instance

   Security

   You can check the security groups and rules applied to the instance. For more information, see Modify security group.

   Category	Description
   Security group	List of configured security groups
   Detailed rules	Detailed rules of the configured security groups - Inbound tab: Inbound rules of the applied security groups - Outbound tab: Outbound rules of the applied security groups

   Volume

   You can check the volume information connected to the instance.

   Category	Description
   Volume name	Name of the volume
   Volume ID	Unique ID of the volume
   Status	Status of the volume - For more information about volume status, see Volume states
   Mount point	Connected mount point
   Type	Type of the volume
   Size	Size of the volume
   Snapshot schedule	Connected snapshot schedule policy
   Delete with instance	Whether the volume is configured to be deleted when the instance is deleted
   Created at	Creation date and time of the volume

   caution

   • The number of resources that can be attached to a single instance, such as network interfaces, volumes, and GPUs, is limited and cannot exceed that limit. The total number of attachable resources differs by instance family. If attaching an additional network interface or volume fails, reduce the number of attached resources and try again.

   Task log

   You can check the task logs to see which user ran which task command.

   Category	Item	Description
   ID	-	Unique ID of the request log
   Type	create	Instance creation task
   	delete	Instance deletion task
   	stop	Instance stop task
   	shelve	Instance shelve task
   	start	Instance start task
   	reboot	Instance reboot task
   	revertResize	Task to revert instance type change
   	confirmResize	Task to confirm instance type change
   	resize	Instance type change task
   	attach_interface	Task to attach an interface to the instance
   	detach_interface	Task to detach an interface from the instance
   	attach_volume	Task to attach a volume to the instance
   	detach_volume	Task to detach a volume from the instance
   	createImage	Task to create an instance image
   User account	-	Account ID of the user who ran the task
   Requested at	-	Date and time when the task was run

   Monitoring

   You can manage resources flexibly and efficiently by using monitoring, while minimizing the resources required for management.
   Instance monitoring is divided into Basic monitoring and Detailed monitoring.

Delete instance

You can delete an instance.

caution

Deleted instance resources are fully released after termination and cannot be recovered.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.
2. In the Instance menu, select [⋮] button > Delete for the instance to delete.
3. In the pop-up window, enter the confirmation text, then click the [Delete] button.

info

• When an instance is deleted, connected network interfaces are handled as follows.
  • A network interface created as New interface when the instance was created is deleted together.
  • A network interface connected by selecting Existing interface when the instance was created remains even after the instance is deleted, and you must delete the network interface separately.

Monitoring

Monitoring is divided into basic monitoring and detailed monitoring.

Basic monitoring

You can check the basic monitoring results.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.

2. In the Instance menu, select the instance for which you want to check task log information.

3. In the Monitoring tab, click the Basic monitoring tab, then check the information.

   Item	Description
   vCPU usage (Core)	Total vCPU usage over time
   Disk Read/Write Bytes	Disk (volume) read and write usage over time
   Network Rx	Network Rx usage over time
   Network Tx	Network Tx usage over time

   info

   • For an instance with multiple network interfaces connected, the Network RX/TX value for each network interface is displayed.

Detailed monitoring

For detailed monitoring, you can check data after installing the monitoring agent in advance. The installation method of the monitoring agent is as follows.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.
2. In the Instance menu, select the instance on which to install the monitoring agent.
3. Click [Go to installation guide] displayed in the Detailed monitoring tab.
4. After installing the monitoring agent according to the guide, set each item in the Metric explorer tab under Management > Monitoring > Explorer. For more information, see Management > Monitoring > How-to Guides > Use explorer.
5. If you need to check logs, you can view each item in the Log explorer under Management > Monitoring > Explorer. For more information, see Management > Monitoring > How-to Guides > Use explorer.
6. A default monitoring dashboard is provided, but you can configure a custom dashboard to suit your monitoring purpose. For more information, see Management > Monitoring > How-to Guides > Use dashboard.

Associate public IP

You can associate a public IP to the instance.

Permission note

Only users with the project administrator permission can connect a public IP.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.
2. In the Instance menu, select [⋮] button > Connect public IP.
3. In the pop-up window, select the network interface and private IP address to connect, then click the [Confirm] button.

Disassociate public IP

You can disconnect a connected public IP.

Permission note

Only users with the project administrator permission can disconnect a public IP.

caution

If you disconnect only the public IP without deleting the resource connected to it, the public IP is not released. In this case, it is billed even if you do not use the public IP.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.
2. In the Instance menu, select [⋮] button > Disconnect public IP.
3. In the pop-up window, select the network interface and public IP to disconnect, then check "Automatically delete the public IP after disconnecting it from the instance.".
4. Click the [Disconnect] button.

Modify security group

You can modify the security group connected to the network interface of the instance. One or more security groups are configured by default on the primary network interface.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.

2. In the Instance menu, select [⋮] button > Modify security group.

3. In the pop-up window, select the security group to apply to the instance.

   • If multiple security groups are applied, all rules in each security group are applied to the instance.

   Modify security group

4. Click the [Save] button.

Network interface

Attach network interface

You can attach a network interface to the instance.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.
2. In the Instance menu, select [⋮] button > Attach network interface.
3. In the pop-up window, check the information, then select the network interface to attach.
4. Click the [Confirm] button.

Detach network interface

You can detach a connected secondary network interface from the instance.

Permission note

• The primary network interface cannot be detached.

1. Go to Compute > Beyond Compute Service > Virtual Machine in the KakaoCloud console.
2. In the Instance menu, select [⋮] button > Detach network interface.
3. In the pop-up window, check the information, then select the network interface to detach.
4. Click the [Confirm] button.

Set time reference

Consistent and accurate time reference is important for many server operations and processes. The images provided by KakaoCloud use time synchronization services provided by the operating system by default, such as Network Time Protocol(NTP), Chrony, and systemd-timesyncd. Through these time synchronization services, multiple servers can operate based on the same time standard and reference consistent time. However, these external services can be used only when the server has internet access.

In a local network environment, you can synchronize time using the NTP service provided by KakaoCloud. In a Linux environment, you can use the Chrony client to use the KakaoCloud NTP service inside the instance.

info

• The KakaoCloud synchronization service is provided through the IPv4 address 169.254.169.123.
• VPCs created before February 21, 2024 do not provide an NTP service endpoint, and this will be migrated gradually.

RHEL family

1. Install the Chrony package.

   sudo yum install chrony

2. Open the /etc/chrony.conf file and add the following line.

   server 169.254.169.123 prefer iburst minpoll 4 maxpoll 4

3. Restart the chronyd daemon and apply the changes.

   sudo service chronyd restart

4. Use the following command to configure chronyd to start whenever the system boots.

   sudo chkconfig chronyd on

5. Check whether Chrony synchronizes time using the IP 169.254.169.123. Also check whether the default time source marked with ^* is set to 169.254.169.123.

   chronyc sources

   Output

   MS Name/IP address         Stratum Poll Reach LastRx Last sample
   ===============================================================================
   ^- 193.123.243.2                 2   6    17     9  -8932us[-8909us] +/- 4550us
   ^- ec2-13-209-84-50.ap-nort>     2   6    17     9  -8534us[-8512us] +/- 5038us
   ^* 169.254.169.123               2   4    17     9    +11us[  +34us] +/-   39ms

6. Check the time synchronization status of Chrony.

   Check time synchronization status

   chronyc tracking

   Output

   Reference ID    : A9FEA97B (169.254.169.123)
   Stratum         : 3
   Ref time (UTC)  : Wed Jun 28 08:14:40 2023
   System time     : 0.000019450 seconds fast of NTP time
   Last offset     : +0.000022669 seconds
   RMS offset      : 0.000022669 seconds
   Frequency       : 1.352 ppm slow
   Residual freq   : +2.810 ppm
   Skew            : 0.061 ppm
   Root delay      : 0.076084495 seconds
   Root dispersion : 0.000831026 seconds
   Update interval : 2.0 seconds
   Leap status     : Normal
   

Debian family

1. Install the Chrony package.

   sudo apt install chrony

2. Open the /etc/chrony/chrony.conf file and add the following line to the file.

   server 169.254.169.123 prefer iburst minpoll 4 maxpoll 4

3. Then restart the chronyd daemon to apply the changes.

   sudo /etc/init.d/chrony restart

4. Check whether Chrony synchronizes time using the IP 169.254.169.123. Check whether the default time source marked with ^* is set to 169.254.169.123.

   Check whether time synchronization is enabled

   chronyc sources

   Output

   MS Name/IP address         Stratum Poll Reach LastRx Last sample
   ===============================================================================
   ^* 169.254.169.123               2   4    37     4    +41us[ +189us] +/-   39ms
   ^- pugot.canonical.com           2   6    17    18  -8895us[-8864us] +/-  162ms
   ^- prod-ntp-3.ntp1.ps5.cano>     2   6    17    18  -3232us[-3203us] +/-  125ms
   ^- prod-ntp-5.ntp1.ps5.cano>     2   6    17    19  -1723us[-1707us] +/-  123ms
   ^- alphyn.canonical.com          2   6    17    18  -2344us[-2321us] +/-  140ms
   ^- 121.174.142.82                3   6    17    19  -9870us[-9853us] +/-   28ms
   ^- ntp-seoul.gombadi.com         2   6    17    20  -8532us[-8519us] +/-   52ms
   ^- send.mx.cdnetworks.com        2   6    17    18  -8997us[-8971us] +/-   29ms
   ^- 193.123.243.2                 2   6    17    19  -9014us[-8994us] +/- 4132us

5. Check the time synchronization status of Chrony.

   Check time synchronization status

   chronyc tracking

   Output

   Reference ID    : A9FEA97B (169.254.169.123)
   Stratum         : 3
   Ref time (UTC)  : Wed Jun 28 08:25:52 2023
   System time     : 0.000156159 seconds slow of NTP time
   Last offset     : -0.000184961 seconds
   RMS offset      : 0.000184961 seconds
   Frequency       : 5.999 ppm fast
   Residual freq   : -0.600 ppm
   Skew            : 35.807 ppm
   Root delay      : 0.076914668 seconds
   Root dispersion : 0.000669460 seconds
   Update interval : 16.2 seconds
   Leap status     : Normal