In an AHV host with just the CVM and two other VMs running, there’s just about 1G of free memory. There’s 28 GB for the CVM and 8 GB each for the two other VMs. That is just 44 our of 125 GB of RAM on the host.
[root@ahv ~]# head /proc/meminfo MemTotal: 131859556 kB MemFree: 286384 kB MemAvailable: 1151500 kB Buffers: 113908 kB Cached: 632172 kB SwapCached: 0 kB Active: 839356 kB Inactive: 5600 kB Active(anon): 106800 kB Inactive(anon): 148 kB
This is because, from AOS 5.0, almost all memory is assigned to hugepages.
[root@ahv]# grep Huge /proc/meminfo AnonHugePages: 0 kB HugePages_Total: 63360 HugePages_Free: 40832 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB
This host has 123 GB (HugePages_Total * Hugepagesize) assigned to huge pages!
What are huge pages? How are they different from normal page?