Bug 2481050

Summary:	High CPU utilization by updatedb when running inside virtual machine with attached virtiofs filesystem.
Product:	[Fedora] Fedora	Reporter:	Bronek Kozicki <brok>
Component:	plocate	Assignee:	Zbigniew Jędrzejewski-Szmek <zbyszek>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	unspecified
Version:	44	CC:	epel-packagers-sig, msekleta, zbyszek
Target Milestone:	---	Keywords:	EasyFix, Improvement, Performance, UserExperience
Target Release:	---
Hardware:	Unspecified
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Bronek Kozicki 2026-05-24 14:53:43 UTC

I was wondering why my Fedora 44 is slow running inside a virtual machine; finally I found that it is wasting CPU scanning huge imported filesystem from the host, via virtiofs. The fix is very simple, add virtiofs to PRUNEFS list inside /etc/updatedb.conf. Since this list already has 9p and various networked / distributed filesystems, the fact that it does not currently have virtiofs is an obvious omission.

Reproducible: Always

Steps to Reproduce:
1. construct a virtual machine with virtiofs attached, pointing to a very large filesystem
2. install Fedora 44 inside the virtual machine
3. watch updatedb trying to index the imported virtiofs filesystem
Actual Results:
large CPU utilization by /usr/bin/updatedb

Expected Results:
small or no CPU utilization by /usr/bin/updatedb

Additional Information:
Unexpectedly for the user, updatedb is trying to index a virtiofs filesystem. The updatedb.conf can be used to prevent this and indeed it is used for a range of filesystems including 9p (similar filesystem to virtiofs). The fix is for the user to add virtiofs to PRUNEFS in /etc/updatedb.conf, or ideally for the package to do it in the package provided configuration. This configuration is owned by the package itself - plocate project does not have a source file for default configuration.