1 vCPU = access to 1 core, 2 vCPUs = access to 2 cores, etc…
At least on Ubuntu/Debian, the /proc/cpuinfo has a separate entry for each CPU core. So when you scan through the file you might see cpu cores: 1 but there is a separate entry for each core. For example:
root@ubuntu-s-2vcpu-4gb-lon1-01:~# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 63
model name : Intel(R) Xeon(R) CPU E5-2650L v3 @ 1.80GHz
stepping : 2
microcode : 0x1
cpu MHz : 1799.998
cache size : 30720 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl eagerfpu pni pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm invpcid_single retpoline kaiser vnmi ept fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid xsaveopt arat
bugs : cpu_meltdown spectre_v1 spectre_v2
bogomips : 3599.99
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:
processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 63
model name : Intel(R) Xeon(R) CPU E5-2650L v3 @ 1.80GHz
stepping : 2
microcode : 0x1
cpu MHz : 1799.998
cache size : 30720 KB
physical id : 1
siblings : 1
core id : 0
cpu cores : 1
apicid : 1
initial apicid : 1
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl eagerfpu pni pclmulqdq vmx ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm invpcid_single retpoline kaiser vnmi ept fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid xsaveopt arat
bugs : cpu_meltdown spectre_v1 spectre_v2
bogomips : 3599.99
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:
Knowing that, some commandline-fu to output the number of cores is:
cat /proc/cpuinfo | grep processor | wc -l
which is just finding the number of lines in cpuinfo with processor. Here’s an even more thorough answer: https://askubuntu.com/questions/724228/how-to-find-the-number-of-cpu-cores-including-virtual
Question
To contexualize: I’m using Percona to generate a mysql config to better suit the hardware, but since everything is VM here I’m not sure what to put in this field (considering the 2 vcpu 4gb ram):
“How many CPUs does your system have?
Enter the total number of CPU cores in your server, including hyperthreading. For example, if you have two 4-core CPUs with hyperthreading, enter 16.”