I cannot log in to the CVM via VNC, and the error message “Cannot allocate memory” appears.
This issue may be caused by too many huge pages. The default huge page size is 2048 KB. The number of huge pages is stated in
/etc/sysctl.conf. If there are 1280 huge pages (as shown below), 2.5 GB of memory are taken. In case of low instance specification, there may not be enough memory for proper system running, and you cannot enter the system after restarting it.
cat /etc/sysctl.conf | grep hugepages
If there are many huge pages, perform the following steps to modify the configurations.
4. Run the following command to open the
/etc/sysctl.conf configuration file with VIM editor.
Press i to enter the edit mode and reduce the value of the
vm.nr_hugepages as needed.
Press Esc, enter :wq, and press Enter to save the configurations and exit the VIM editor.
Run the following command for the configuration to take effect immediately.
Then restart the CVM, and you can log in normally.