Each entry answers the question first, then gives a command or a pointer to the page that covers it properly. Commands assume Ubuntu 24.04, Debian 12 or AlmaLinux 9.
What is a vCPU?
A vCPU is a virtual processor the hypervisor gives your server. It maps to one hardware thread on a physical host core, scheduled when your guest has work to run. Four vCPUs means the kernel can run four threads in parallel. It does not mean four whole physical cores reserved for you.
nproc
lscpu | grep -E 'Model name|^CPU\(s\)'See the plan table for vCPU counts from 1 on Spark to 8 on Hyper.
What is CPU steal time?
Steal time is the share of time your vCPU was ready to run but the hypervisor was serving another guest. Linux reports it as st. A little is normal on shared hosts. Sustained high steal while your own load is flat means contention on the host, not a problem in your code.
vmstat 5 6 # last column, st
top # %st on the Cpu(s) lineThe performance triage guide shows how to tell steal apart from I/O wait.
What is NVMe storage?
NVMe is a protocol for talking to flash storage over PCIe rather than the older SATA path built for spinning disks. It supports many deep command queues, so random reads and writes finish with far less latency. FastNode volumes are NVMe-backed SSD, presented to your guest as a virtual disk.
The trade-offs are covered in NVMe vs SATA SSD.
What are IOPS?
IOPS means input/output operations per second: how many separate reads or writes a disk completes each second. Databases care about it more than raw throughput, because they issue lots of small random 4 KB or 8 KB requests. Latency per operation matters as much as the headline number, so measure both under your real workload.
sudo apt install fio sysstat
iostat -x 5 # r/s, w/s and await per deviceTuning advice lives in database tuning on NVMe.
What is unmetered bandwidth vs a bandwidth cap?
A bandwidth cap is a monthly allowance in terabytes; go over and you pay extra or get throttled. Unmetered means traffic is not counted towards a bill. The limit is the port speed instead. Every FastNode plan has a 1 Gbps port and unmetered traffic, subject to the acceptable use policy.
What is a dedicated IPv4 address?
A dedicated IPv4 address is a public address assigned only to your server, not shared behind NAT with other customers. You can run any service on any port, point DNS records at it and set its reverse DNS. FastNode includes one per server. IPv6 is not offered, and extra addresses are not listed as a feature.
What is reverse DNS (a PTR record)?
Reverse DNS maps an IP address back to a hostname, the opposite of an A record. Mail servers check it: a sending IP whose PTR does not match its forward name often lands in spam. You set the PTR for your FastNode IPv4 in the portal, after creating the matching A record.
dig -x 203.0.113.10 +short
dig mail.example.com A +shortWhat is the difference between a snapshot and a backup?
A snapshot captures the whole disk at one moment, usually kept alongside the server for quick rollback before an upgrade. A backup is a copy kept separately, on a schedule, so it survives the server itself being lost. Snapshots are a portal feature; if backups are enabled on your server, check the portal for the schedule.
Use both, plus an off-server copy of your data. Details in backups and snapshots.
What is rescue mode?
Rescue mode boots your server from a small recovery system instead of its own disk. Your real disk is attached but not running, so you can mount it, fix a broken fstab, reset a firewall that locked you out or copy data off. Start it from the portal and work in it through the browser console.
lsblk
mount /dev/sda1 /mnt # device name varies; check lsblkWhat is a hypervisor (VMware)?
A hypervisor is the software layer that runs many virtual machines on one physical host, giving each its own virtual CPU, memory and disk. FastNode uses VMware vSphere. Your server is a full virtual machine with its own kernel, unlike a container, which shares the host kernel with its neighbours.
systemd-detect-virt # prints vmwareMore in VMs vs containers.
What do root access and unmanaged mean?
Root access means you control the operating system completely: install packages, change the kernel settings, open ports. Unmanaged means nobody else patches, backs up or monitors what runs inside it. FastNode servers are unmanaged. We keep the host, network and portal running; the guest operating system is yours to look after.
The trade is explained in managed vs unmanaged, and the first-hour checklist covers the basics.
What is an outbound port 25 block?
Port 25 is the SMTP port mail servers use to talk to each other. Hosts block outbound connections on it by default so a compromised server cannot send spam. On FastNode it is blocked until you request an unblock in the portal. Sending through a mail provider on port 587 with authentication works regardless.
nc -vz -w 5 smtp.example.com 25 # times out while blocked
nc -vz -w 5 smtp.example.com 587What is a self-hosted runner?
A self-hosted runner is a CI agent you install on your own server. It polls GitHub Actions or GitLab for jobs, runs them locally and reports results back. Because the disk persists, Docker layers and dependency caches stay warm between builds, and cost is a flat monthly fee instead of per-minute billing.
Set one up with the GitHub Actions runner guide or the GitLab Runner guide, and size it using CI runners.