From ac84610380645d3ca113b316988a855d96296caa Mon Sep 17 00:00:00 2001 From: majorlinux Date: Mon, 11 May 2026 18:32:01 -0400 Subject: [PATCH] wiki: add 1 vCPU nice/ionice limitation note to ClamAV article nice -n 19 only yields when other processes compete; on single-core VPS boxes the scan still saturates CPU. Document the expectation. Co-Authored-By: Claude Opus 4.6 (1M context) --- .../security/clamscan-cpu-spike-nice-ionice.md | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/05-troubleshooting/security/clamscan-cpu-spike-nice-ionice.md b/05-troubleshooting/security/clamscan-cpu-spike-nice-ionice.md index 6fba02d..a80e07b 100644 --- a/05-troubleshooting/security/clamscan-cpu-spike-nice-ionice.md +++ b/05-troubleshooting/security/clamscan-cpu-spike-nice-ionice.md @@ -1,11 +1,17 @@ --- -title: "ClamAV Safe Scheduling on Live Servers" +title: ClamAV Safe Scheduling on Live Servers domain: troubleshooting category: security -tags: [clamav, cpu, nice, ionice, cron, vps] +tags: + - clamav + - cpu + - nice + - ionice + - cron + - vps status: published created: 2026-04-02 -updated: 2026-04-02 +updated: 2026-05-11T18:31 --- # ClamAV Safe Scheduling on Live Servers @@ -75,6 +81,7 @@ kill - `ionice -c 3` (Idle) requires Linux kernel ≥ 2.6.13 and CFQ/BFQ I/O scheduler. Works on most Ubuntu/Debian/Fedora systems. - On multi-core servers, consider also using `cpulimit` for a hard cap: `cpulimit -l 30 -- clamscan ...` - Always keep `--exclude=/sys` (and optionally `--exclude=/proc`, `--exclude=/dev`) to avoid scanning virtual filesystems. +- **1 vCPU limitation:** `nice` and `ionice` only help when other processes compete for resources. On a single-core VPS, clamscan will still saturate the CPU at 57-100% even with `nice -n 19 ionice -c 3` — there's nothing to yield to. Accept the weekly spike as benign, or reduce scan scope to shorten the window. ## Related