If the HugePages_Total output is 0, see the memory issue analysis to find the causes of problems.
If the HugePages_Total output is not 0, there are huge pages. The huge page size equals to HugePages_Total * Hugepagesize. Check whether huge pages are configured by a malicious program, or if they are unnecessary, you can comment out the vm.nr_hugepage configuration item in the /etc/sysctl.conf file, and then run the sysctl -p command to abandon huge pages.
Directions
Viewing memory utilization
The free command output may vary with the Linux distributions, which is unreliable for calculating the memory utilization. Perform the following steps to view the memory utilization on the Monitoring page of the CVM console.
1. Log in to the CVM console and access the Instances page.
2. Click the ID/Name of the instance to enter its details page. Select the Monitoring tab.
3. View memory utilization in the Memory Monitor section.
Calculating memory utilization
The memory utilization is the ratio of memory used to total memory, excluding the buffer and system cache. The calculation formula is as follows:
= (Total - available)100% / Total
= (Total - (Free + Buffers + Cached + SReclaimable - Shmem)) * 100% / Total
= (Total - Free - Buffers - Cached - SReclaimable + Shmem) * 100% / Total
The required parameters Total, Free, Buffer, Cached, SReclaimable, and Shmem can be obtained in /proc/meminfo. Below is an example of /proc/meminfo.
1. [root@VM_0_113_centos test]# cat /proc/meminfo
2. MemTotal: 16265592 kB
3. MemFree: 1880084 kB
4. ......
5. Buffers: 194384 kB
6. Cached: 13647556 kB
7. ......
8. Shmem: 7727752 kB
9. Slab: 328864 kB
10. SReclaimable: 306500 kB
11. SUnreclaim: 22364 kB
12. ......
13. HugePages_Total: 0
14. Hugepagesize: 2048 kB
The parameters are described as follows:
Parameter
Description
MemTotal
Total system memory
MemFree
Free memory
Buffers
Cached page used by block devices for reads/writes and file system metadata (such as SuperBlock)
Cached
Page cache, including POSIX/SysV shared memory and shared anonymous mmap of tmpfs
Shmem
Including shared memory, tmpfs, etc.
Slab
Memory allocated by the kernel slab memory allocator, which can be viewed using the slabtop command
SReclaimable
Reclaimable slabs
SUnreclaim
Non-reclaimable slabs
HugePages_Total
Total number of huge pages
Hugepagesize
Size of a huge page
Memory issue analysis
If the problem persists, or an error shown below appears during your use of CVM, refer to the corresponding solutions:
