Inspecting Ncloud Tool Kit

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Available in VPC

Linux Ncloud Tool Kit (Linux NTK) is a tool kit for Linux VMs provided on NAVER Cloud Platform. You can easily operate and maintain NCP VM through server status diagnosis and Disk I/O measurement features.

Diagnosis of server status

You can use the SYSTEM CHECKING tool in NTK to diagnose the state of the Linux server, identify symptoms and causes, and check the troubleshooting measures.

Note

The items for diagnosing server status differ according to the types of hypervisor hosting VM.

XEN environment Linux VM status diagnosis

Account Config File

The following concerns checking the account configuration file.

Feature Cause Troubleshooting Measure
1. Check whether /etc/passwd file exists
  • NTK execution result:
    [NOK] /etc/passwd file does not exist
 No /etc/passwd file exists Copy the existing backup file using the following command
# cp -p /etc/passwd- /etc/passwd
2. Check whether /etc/shadow file exists
  • NTK execution result:
    [NOK] /etc/shadow file does not exist
 No /etc/shadow file exists Copy the existing backup file using the following command
# cp -p /etc/shadow- /etc/shadow
3. Check whether /etc/group file exists
  • NTK execution result:
    [NOK] /etc/group file does not exist
 No /etc/group file exists Copy the existing backup file using the following command
# cp -p /etc/group- /etc/group

Mandatory Process

The following concerns checking the processes mandatory for operating NCP Linux VM.

Feature Cause Troubleshooting Measure
1. Check for existence of the agent file for monitoring
  • NTK execution result:
    [NOK] cloud insight agent is Not exist.. Please Check
 No agent file for monitoring exists See the following guide to install the monitoring agent
2. Check for existence of the agent_updater file for monitoring
  • NTK execution result:
    [NOK] nsight_updater Nok exist or permission(-rw-r--r--) is Not OK... Please Check
 No agent_updater file for monitoring exists See the following guide to install the monitoring agent
3. Check the status of monitoring service registration (enable) upon booting
  • NTK execution result
    [NOK] cloud insight process auto start is Not OK.. Please check
 The monitoring service is not set to auto-start upon booting See the following guide to install the monitoring agent
4. Check whether the Xentools package is installed
  • NTK execution result:
    [NOK] xe-guest-utilites installation status is Not OK... Please Check
 The Xentools package is not properly installed See the following guide to re-install Xentools
5. Check the status of Xentools service registration (enable) upon booting
  • NTK execution result:
    [NOK] xentools auto start is Not OK.. Please check
 The Xentools service is not set to auto-start upon booting See the following guide to re-install Xentools

Ncloud Setup Script

The following concerns checking the setting script mandatory for operating NCP Linux VM.

Caution

Be sure to check this item when you create a custom server image or reset the administrator password on the console.

Feature Cause Troubleshooting Measure
1. Check the ncloud_auto.sh script
  • NTK execution result:
    [NOK] ncloud_auto.sh file does NOT exist.. Please Check
 No ncloud_auto.sh file exists
  • Install the ncloud_auto.sh setup script
  • Create a new server and copy the /usr/local/etc/ncloud_auto.sh script to under /usr/local/etc/ of the server in question
The ncloud_auto.sh file exists, but the permission does not satisfy the condition Set the file permission using the following command:
# chmod 700 /usr/local/etc/ncloud_auto.sh
2. Check for the mandatory content in the ncloud_auto.sh script
  • NTK execution result:
    [NOK] Mandatory Content does not exist in ncloud_auto.sh
 The ncloud_auto.sh script contains invalid content
  • Delete the existing ncloud_auto.sh script and newly install the script
  • Create a new server and copy the /usr/local/etc/ncloud_auto.sh script to under /usr/local/etc/ of the server in question
3. Check for the mandatory script settings that must be executed upon booting
  • NTK execution result:
    [NOK] ncloud_auto Not exist in /etc/rc.local... Please Check
 No ncloud_auto.sh syntax exists in rc.local Insert the following syntax in /etc/rc.local
/usr/local/etc/ncloud_auto.sh > /tmp/. ncloud_out.log 2> /tmp/.ncloud_error.log &
4. Check the status of the mandatory service that must be executed upon booting
  • NTK execution result:
    [NOK] ncloud_auto.service is not enabled... Please Check
 ncloud_auto.service is disabled Enable the ncloud_auto service using the following command:
# systemctl enable ncloud_auto.service
5. Check the status of the rc.local file and the related services
  • NTK execution result:
    [NOK] /etc/rc.local or permission(-rwxr-xr-x) is Not OK.. Please Check
 Permission of the rc.local file does not meet the condition Set the file permission using the following command:
# chmod 755 /etc/rc.local
rc-local.service is disabled Enable the service using the following command:
1. CentOS 7.x
# systemctl unmask rc-local.service
2. Ubuntu
# systemctl enable rc-local.service
3. Rocky Linux 8.x
# systemctl enable rc-local.service

DNS Config

The following concerns checking DNS configuration and status.

Feature Cause Troubleshooting Measure
1. Check the /etc/resolv.conf file
  • NTK execution result:
    [NOK] There is no exsit /etc/resolv.conf
 No /etc/resolv.conf file exists Create a resolv.conf file and update the permission using the following commands. Then, see the following guide to inspect the DNS configuration
# touch /etc/resolv.conf
# chmod 644 /etc/resolv.conf
2. Check the connection to NAVER Cloud's internal server
  • NTK execution result:
    [NOK] Can't connect to Naver Cloud internal server
 Attempt to connect to NAVER Cloud's internal server failed. See the following guide to inspect the DNS configuration
3. Check the mandatory content in the /etc/resolv.conf file
  • NTK execution result:
    [NOK] The configuration does not exist or is incorrect(127.0.0.53) in resolv.conf
    [NOK] The configuration does not exist or is incorrect(169.254.169.53,169.254.169.54) in resolv.conf
 Mandatory configuration is missing or erroneous in the /etc/resolv.conf file See the following guide to inspect the DNS configuration
4. Check the first DNS information in the /etc/resolv.conf file or systemd-resolve
  • NTK execution result:
    [NOK] First DNS Information in /etc/resolv.conf
    [NOK] First DNS Information in systemd-resolve
 The first DNS information is not the IP information provided by NCP See the following guide to inspect the DNS configuration

Network Config

The following concerns checking the network configuration.

Feature Cause Troubleshooting Measure
1. Check the network configuration file
  • NTK execution result:
    [NOK] /etc/networks file does not exist
    [NOK] /etc/sysconfig/network file does not exist
 No network configuration file exists Recreate the network configuration file and restart the network service
2. Check the dhcp configuration of the eth0 interface
  • NTK execution result:
    [NOK] eth0 is configured by [BOOTPROTO value]
 BOOTPROTO of eth0 is not set to dhcp Set BOOTPROTO to dhcp and restart the network service
1. CentOS/Rocky Linux file path: /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
MTU=8950
BOOTPROTO=dhcp
ONBOOT=yes
2. Ubuntu file path: /etc/network/interfaces
auto eth0
iface eth0 inet dhcp
post-up /sbin/ifconfig eth0 mtu 8950
3. Check the BOOTPROTO setting of the additional network interface
  • NTK execution result:
    [NOK] BOOTPROTO entry does not exist in [NIC name]
 BOOTPROTO has no value set in the additional network interface Assign a value to BOOTPROTO and restart the network service
4. Check the Network Manager service status (applicable to CentOS 7 only)
  • NTK execution result:
    [NOK] NetworkManager is active
 When Network Manager is enabled in the CentOS 7 environment, an error occurs during dhcp operation Disable the Network Manager service using the following commands:
# systemctl disable NetworkManager
# systemctl stop NetworkManager
# systemctl mask NetworkManager
# chkconfig network on
# systemctl restart network.service

root File System

The following concerns checking the root file system status.

Feature Cause Troubleshooting Measure
1. Run a full check on the usage rate of the root file system (/)
  • NTK execution result:
    [NOK] rootfs is Not OK.. (90%) Please Check
    [NOK] rootfs can't write(/tmp)
    [NOK] rootfs can't touch and delete(/tmp/rotest-temps)
 The root file system (/) has a high usage rate (90% or higher) Delete unnecessary files from the root file system (/)
2. Check for existence of the /tmp directory
  • NTK execution result:
    [NOK] /tmp does not exist.
 No /tmp directory exists Create a directory using the following command:
# mkdir /tmp
3. Check the permission of the /tmp directory
  • NTK execution result:
    [NOK] /tmp permission(drwxrwxrwt.) is not ok
 Permission of /tmp does not meet the condition Set the permission using the following command:
# chmod 1777 /tmp
4. Check the owner of the /tmp directory
  • NTK execution result:
    [NOK] /tmp user (user name) is not ok
 Owner of /tmp does not meet the condition Set the owner of the directory using the following command:
# chown root: /tmp
5. Check the owner group of the /tmp directory
  • NTK execution result:
    [NOK] /tmp group (user name) is not ok
 Owner group of /tmp does not meet the condition Set the owner group of the directory using the following command:
# chown :root /tmp

fstab File

The following concerns checking the file (/etc/fstab) storing file system mount information.

Feature Cause Troubleshooting Measure
1. Check for existence of /etc/fstab
  • NTK execution result:
    [NOK] /etc/fstab file does not exist
 No /etc/fstab file exists. Create the file using the following commands, and run inspection by referring to the relevant guide
# touch /etc/fstab
# chmod 644 /etc/fstab
2. Check the grammar of /etc/fstab
  • NTK execution result:
    Field(*),Number of fields in fstab: [NOK]
    Field(1),Source device: [NOK]
    Field(2),Mount point dir: [NOK]
    Field(3),Filesystem exist: [NOK]
    Field(4),Options value: [NOK]
    Field(5),Config of filesystem dump: [NOK]
    Field(6),Config of filesystem check: [NOK]
 The content registered in /etc/fstab is incorrect or of an invalid format Inspect the fstab file by referring to the following guide.

grub Config

The following concerns checking the grub configuration.

Feature Cause Troubleshooting Measure
1. Check the grub file
  • NTK execution result:
    [NOK] /boot/grub2/grub.cfg file does not exist
    [NOK] /boot/grub/grub.cfg file does not exist
 The mandatory file for booting has been deleted or damaged
  • Back up the storage snapshot and create a new VM or restore the VM for use
  • Create a GRUB file using the following command:
    • # grub2-mkconfig -o /boot/grub2/grub.cfg

Kernel Image

The following concerns checking the kernel image list of NCP Linux VM.

Feature Cause Troubleshooting Measure
Check the kernel image
  • NTK execution result:
    [NOK]/boot folder does not exist
 No /boot directory exists Back up the storage snapshot and create a new VM or restore the VM for use

Repo Config

The following concerns checking the repository configuration file.

Feature Cause Troubleshooting Measure
1. Check the repository configuration directory
  • NTK execution result:
    [NOK] /etc/apt folder does not exist
    [NOK] /etc/yum.repos.d folder does not exist
 No repository configuration directory exists Create a repository configuration directory using the following command:
1. CentOS / Rocky Linux
# mkdir -p /etc/yum.repos.d/
2. Ubuntu
# mkdir -p /etc/apt/
2. Check the repository configuration file
  • NTK execution result:
    [NOK] /etc/apt/sources.list file does not exist
    [NOK] /etc/yum.repos.d/CentOS-Base.repo file does not exist
    [NOK] /etc/yum.repos.d/Rocky-BaseOS.repo file does not exist
 No repository configuration file exists Download the repository configuration file using the following command:
1. CentOS 7.x
# wget -q http://init.ncloud.com/server/linux/repo/centos7/CentOS-Base.repo -O /etc/yum.repos.d/CentOS-Base.repo
2. Ubuntu 18.04
# wget -q http://init.ncloud.com/server/linux/repo/ubuntu18/sources.list -O /etc/apt/sources.list
3. Ubuntu 20.04
# wget -q http://init.ncloud.com/server/linux/repo/ubuntu20/sources.list -O /etc/apt/sources.list
4. Rocky Linux 8.x
# wget -q http://init.ncloud.com/server/linux/repo/rocky8/Rocky-BaseOS.repo -O /etc/yum.repos.d/Rocky-BaseOS.repo

Mandatory Package

The following concerns checking the packages essential for operating NCP Linux VM.

Feature Cause Troubleshooting Measure
1. Check for existence of the wget package
  • NTK execution result:
    [NOK] wget package is not installed
 No wget package is installed Download the package using the following command:
1. CentOS / Rocky Linux
# yum install wget
2. Ubuntu
# apt install wget
2. Check whether the /usr/bin/wget file can be executed
  • NTK execution result:
    [NOK] /usr/bin/wget file does not exist or permission is not OK... Please Check
 No wget execution file exists or there is no permission to execute the file Download the package using the following command:
1. CentOS / Rocky Linux
# yum install wget
2. Ubuntu
# apt install wget
3. Check for existence of the dos2unix package
  • NTK execution result:
    [NOK] dos2unix package is not installed
 No dos2unix package is installed Download the package using the following command:
1. CentOS / Rocky Linux
# yum install dos2unix
2. Ubuntu
# apt install dos2unix
4. Check whether the /usr/bin/dos2unix file can be executed
  • NTK execution result:
    [NOK] /usr/bin/dos2unix file does not exist or permission is not OK... Please Check
 No dos2unix execution file exists or there is no permission to execute the file Download the package using the following command:
1. CentOS / Rocky Linux
# yum install dos2unix
2. Ubuntu
# apt install dos2unix
5. Check for existence of the rpcbind package (not applicable to Ubuntu)
  • NTK execution result:
    [NOK] rpcbind package is not installed
 No rpcbind package is installed. Download the package using the following command:
1. CentOS / Rocky Linux
# yum install rpcbind
6. Check whether the /usr/sbin/rpcbind file can be executed (not applicable to Ubuntu)
  • NTK execution result:
    [NOK] /usr/sbin/rpcbind file does not exist or permission is not OK... Please Check
 No rpcbind execution file exists or there is no permission to execute the file. Download the package using the following command:
1. CentOS / Rocky Linux
# yum install rpcbind
7. Check for existence of the chrony package (not applicable to Ubuntu)
  • NTK execution result:
    [NOK] chrony package is not installed
 No chronyd package is installed. Download the package using the following command:
1. CentOS / Rocky Linux
# yum install chrony
8. Check whether the /usr/sbin/chronyd file can be executed (not applicable to Ubuntu)
  • NTK execution result:
    [NOK] /usr/sbin/chronyd file does not exist or permission is not OK... Please Check
 No chrony execution file exists or there is no permission to execute the file. Download the package using the following command:
1. CentOS / Rocky Linux
# yum install chrony

KVM environment Linux VM status diagnosis

Account Config File

The following concerns checking the account configuration file.

Feature Cause Troubleshooting Measure
1. Check whether /etc/passwd file exists
  • NTK execution result:
    [NOK] /etc/passwd file does not exist
 No /etc/passwd file exists Copy the existing backup file using the following command
# cp -p /etc/passwd- /etc/passwd
2. Check whether /etc/shadow file exists
  • NTK execution result:
    [NOK] /etc/shadow file does not exist
 No /etc/shadow file exists Copy the existing backup file using the following command
# cp -p /etc/shadow- /etc/shadow
3. Check whether /etc/group file exists
  • NTK execution result:
    [NOK] /etc/group file does not exist
 No /etc/group file exists Copy the existing backup file using the following command
# cp -p /etc/group- /etc/group

Mandatory Process

The following concerns checking the processes mandatory for operating NCP Linux VM.

Feature Cause Troubleshooting Measure
1. Check for existence of the agent file for monitoring
  • NTK execution result:
    [NOK] cloud insight agent is Not exist.. Please Check
 No agent file for monitoring exists See the following guide to install the monitoring agent
2. Check for existence of the agent_updater file for monitoring
  • NTK execution result:
    [NOK] nsight_updater Nok exist or permission(-rw-r--r--) is Not OK... Please Check
 No agent_updater file for monitoring exists See the following guide to install the monitoring agent
3. Check the status of monitoring service registration (enable) upon booting
  • NTK execution result
    [NOK] cloud insight process auto start is Not OK.. Please check
 The monitoring service is not set to auto-start upon booting See the following guide to install the monitoring agent

DNS Config

The following concerns checking DNS configuration and status.

Feature Cause Troubleshooting Measure
1. Check the /etc/resolv.conf file
  • NTK execution result:
    [NOK] There is no exsit /etc/resolv.conf
 No /etc/resolv.conf file exists Create a resolv.conf file and update the permission using the following commands. Then, see the following guide to inspect the DNS configuration
# touch /etc/resolv.conf
# chmod 644 /etc/resolv.conf
2. Check the connection to NAVER Cloud's internal server
  • NTK execution result:
    [NOK] Can't connect to Naver Cloud internal server
 Attempt to connect to NAVER Cloud's internal server failed. See the following guide to inspect the DNS configuration
3. Check the mandatory content in the /etc/resolv.conf file
  • NTK execution result:
    [NOK] The configuration does not exist or is incorrect(127.0.0.53) in resolv.conf
    [NOK] The configuration does not exist or is incorrect(169.254.169.53,169.254.169.54) in resolv.conf
 Mandatory configuration is missing or erroneous in the /etc/resolv.conf file See the following guide to inspect the DNS configuration
4. Check the first DNS information in the /etc/resolv.conf file or systemd-resolve
  • NTK execution result:
    [NOK] First DNS Information in /etc/resolv.conf
    [NOK] First DNS Information in systemd-resolve
 The first DNS information is not the IP information provided by NCP See the following guide to inspect the DNS configuration

Network Config

The following concerns checking the network configuration.

Feature Cause Troubleshooting Measure
1. Check the network configuration file
  • NTK execution result:
    [NOK] /etc/networks file does not exist
    [NOK] /etc/sysconfig/network file does not exist
 No network configuration file exists Recreate the network configuration file and restart the network service
2. Check the dhcp configuration of the eth0 interface
  • NTK execution result:
    [NOK] eth0 is configured by [BOOTPROTO value]
 BOOTPROTO of eth0 is not set to dhcp Set BOOTPROTO to dhcp and restart the network service
1. NAVIX/CentOS/Rocky Linux file path: /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
2. Ubuntu file path: /etc/network/interfaces
auto eth0
iface eth0 inet dhcp
3. Check the BOOTPROTO setting of the additional network interface
  • NTK execution result:
    [NOK] BOOTPROTO entry does not exist in [NIC name]
 BOOTPROTO has no value set in the additional network interface Assign a value to BOOTPROTO and restart the network service
4. Check the Network Manager service status (applicable to CentOS 7 only)
  • NTK execution result:
    [NOK] NetworkManager is active
 When Network Manager is enabled in the CentOS 7 environment, an error occurs during dhcp operation Disable the Network Manager service using the following commands:
# systemctl disable NetworkManager
# systemctl stop NetworkManager
# systemctl mask NetworkManager
# chkconfig network on
# systemctl restart network.service

fstab File

The following concerns checking the file (/etc/fstab) storing file system mount information.

Feature Cause Troubleshooting Measure
1. Check for existence of /etc/fstab
  • NTK execution result:
    [NOK] /etc/fstab file does not exist
 No /etc/fstab file exists. Create the file using the following commands, and run inspection by referring to the relevant guide
# touch /etc/fstab
# chmod 644 /etc/fstab
2. Check the grammar of /etc/fstab
  • NTK execution result:
    Field(*),Number of fields in fstab: [NOK]
    Field(1),Source device: [NOK]
    Field(2),Mount point dir: [NOK]
    Field(3),Filesystem exist: [NOK]
    Field(4),Options value: [NOK]
    Field(5),Config of filesystem dump: [NOK]
    Field(6),Config of filesystem check: [NOK]
 The content registered in /etc/fstab is incorrect or of an invalid format Inspect the fstab file by referring to the following guide.

grub Config

The following concerns checking the grub configuration.

Feature Cause Troubleshooting Measure
1. Check the grub file
  • NTK execution result:
    [NOK] /boot/grub2/grub.cfg file does not exist
    [NOK] /boot/grub/grub.cfg file does not exist
 The mandatory file for booting has been deleted or damaged
  • Back up the storage snapshot and create a new VM or restore the VM for use
  • Create a GRUB file using the following command:
    • # grub2-mkconfig -o /boot/grub2/grub.cfg

Kernel Image

The following concerns checking the kernel image list of NCP Linux VM.

Feature Cause Troubleshooting Measure
Check the kernel image
  • NTK execution result:
    [NOK]/boot folder does not exist
 No /boot directory exists Back up the storage snapshot and create a new VM or restore the VM for use

Measuring block storage IOPS

You can measure the performance of the storage connected to the Linux server by using FIO TEST tool of NTK.

Note

This feature only applies to XEN-based Linux VM.

Step 1. Run NTK

To run NTK on a Linux server, follow these steps:

  1. Enter the cd /usr/local/etc command.
  • Move to the path where NTK is located.
  1. Enter the tar zxvf ntk.tar.gz command.
  • The NTK file is unzipped.
  • If you do not have the ntk.tar.gz file or want to replace it with the latest version,
    enter wget -P /usr/local/etc http://init.ncloud.com/server/ntk/linux/xen/ntk.tar.gz to download the file.
  1. Enter the following commands in the given order to run NTK.
cd /usr/local/etc/ntk
./ntk

Step 2. Run FIO TEST

If you need to measure disk IOPS, do the following:

  1. Click (E) EXECUTE - << Run System Apps >>.

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  1. Click (F) FIO TEST - << FOR DISK IO TEST >>.

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  1. Click [YES] to run disk IOPS measurement.

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  1. After selecting the disk to measure the IOPS for, click [OK].
Note

If the server has only 1 disk connected, it is skipped and the disk is automatically selected.

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  1. Select the IOPS test options and click [OK].
  • random read: random reading
  • random write: random writing

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  1. Disk IOPS is measured.

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  1. Once measurement is completed, you can see the output result. After checking them, click [OK].

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  1. If you want to additionally send the log file to NAVER Cloud's Technical support center, then click [Yes]. If you do not, click [No] to exit the procedure.

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  1. If the log is delivered successfully, you can see the delivery success message and a Short-URL that the user can use to download the log.