Virtio disks and NICs

Virtio is the paravirtual disk and network path on a LogicWeb KVM VPS. Your guest talks to the hypervisor through dedicated drivers, which is why throughput and latency stay strong. Emulated IDE and e1000 exist only so an older installer can see hardware before those drivers load. Keep production guests on virtio unless the operating system truly has no virtio support.

How virtio shows up inside the guest

A virtio disk appears as vda (and vdb, and so on), not as sda. A virtio NIC usually shows up as eth0 or ens3, depending on how your distro names interfaces, and it is backed by virtio-net rather than a pretend Intel card. Linux templates we ship already include the drivers. Current Alma Linux, Debian, and Ubuntu guests should stay on virtio for both disk and network. Windows needs the virtio driver ISO attached in the console during install so you can load the SCSI and network drivers when the installer asks for them.

Emulated IDE and e1000 are the compatibility path for a very old OS that cannot load virtio at all. Once drivers are installed, switch back. Running a modern guest on emulated IDE is a self-made bottleneck. It also changes device names, which is how fstab and GRUB break after a later panel change.

When people switch away from virtio

Slow disk tickets and stubborn Windows ISOs often lead someone to flip the disk to IDE “for compatibility.” That can get an ancient installer past the first screen. It is not safer for day-to-day use, and it is slower. Safer means backups, keys, and a locked-down firewall. If the guest already shows vdX devices and still feels slow, check steal time, I/O wait, and whether the guest is swapping. Moving to emulated hardware will not fix a full temporary filesystem or a noisy neighbor.

Mixing a virtio disk with an e1000 NIC usually means the network driver never got installed and nobody returned to finish the job. Prefer virtio for both once the OS can load the drivers. If a Windows installer cannot see the disk, attach the virtio driver ISO and load the drivers from it. That is the compatibility path we mean. Leave the running production guest on virtio afterward.

Practical checklist

Use this order when something will not boot or feels slow:

1. Confirm the panel still shows virtio for disk and NIC on a current Linux or Windows guest.
2. For a fresh Windows install that cannot see the disk, attach the virtio driver ISO and load SCSI and net drivers from it.
3. Only use emulated IDE or e1000 for an OS that has no virtio drivers at all, then plan to move off it when you can.
4. Never change disk type on a live guest you care about without a snapshot. Device names will change.
5. If the disk is already virtio and still slow, look at load, I/O wait, and free space before you touch bus type again.

You have root on the VPS, so guest drivers and fstab are under your control. Stay on virtio for normal workloads. The first-hour firewall still matters more than this setting; a fast NIC with SSH open to the world is not a win.