Linux Question: When does updatedb.mlocat / cron.daily run?

eddie — Wed, 08 Apr 2009 14:39:37 +0000

Uggh. My Ubuntu server’s updatedb.mlocate process is loud as heck and runs *forever*.

I haven’t noticed a performance decrease, as the job is set to run at a fairly low priority. But since I sit near the server, it’s annoying to listen to the hard drive churn for hours and hours. All I wanted to do was re-schedule the job to run when I’m not around. I figured that the job was being kicked off by root’s cron file, but I figured wrong.

After some investigation, I learned the following:

The job parameters are listed in /etc/cron.daily/mlocate.

#! /bin/sh

set -e

[ -x /usr/bin/updatedb.mlocate ] || exit 0

# See ionice(1)
if [ -x /usr/bin/ionice ]; then
IONICE=”/usr/bin/ionice -c3″
fi

$IONICE /usr/bin/updatedb.mlocate

The files in /etc/cron.daily are kicked off by /etc/crontab, not by root’s crontab. For some reason, Ubuntu’s default install runs this process around 6am. Changing this file allowed me to make the job run at 3am.

# /etc/crontab: system-wide crontab
# Unlike any other crontab you don’t have to run the `crontab’
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user command
17 * * * * root cd / && run-parts –report /etc/cron.hourly
25 3 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts –report /etc/cron.daily )
47 3 * * 7 root test -x /usr/sbin/anacron || ( cd / && run-parts –report /etc/cron.weekly )
52 3 1 * * root test -x /usr/sbin/anacron || ( cd / && run-parts –report /etc/cron.monthly )
#

updatedb can be configured to ignore certain paths – since my machine has a number of drives used for backups, I wanted to exclude those from the updatedb job. I accomplished this by editing /etc/updatedb.conf and adding to the PRUNEPATHS listing. Adding paths to the PRUNEPATHS option instructs updatedb to exclude those paths from indexing.

PRUNE_BIND_MOUNTS=”yes”
PRUNEPATHS=”/tmp /var/spool /media /mnt/backup”
PRUNEFS=”NFS nfs nfs4 afs binfmt_misc proc smbfs autofs iso9660 ncpfs coda devpts ftpfs devfs mfs shfs sysfs cifs lustre_lite tmpfs usbfs udf rpc_pipefs”

Eddie On Everything » mlocat

Linux Question: When does updatedb.mlocat / cron.daily run?

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