FSTRIM Cron Job?

[norcal618]

Hello, I'm new to Fedora, coming from using Ubuntu/Mint for the past few years. I followed the recommended partition scheme during install. I have a root partition, home partition, and a swap partition which are all lvm. My ssd is a samsung nvme type pcie ssd. From what I gather TRIM is not enabled by default in Fedora.

I've added the noatime flag to all of the above mentioned partitions in my fstab, and I've created a daily cron job to call fstrim on all partitions. Is this an acceptable way to set up TRIM on Fedora?

[antikythera]

daily is a bit aggressive but it's your choice. the easiest way to set TRIM is to use the timer service which sets TRIM to run once a week

systemctl enable fstrim.timer

[norcal618]

daily is a bit aggressive but it's your choice. the easiest way to set TRIM is to use the timer service which sets TRIM to run once a week

systemctl enable fstrim.timer

Thank you for the response. I work, and basically live on my computer, so it sees allot of use. I used to run trim once a week on Ubuntu, but noticed that I was having some I/O lag with the ssd. I switched over to daily trim since then and have seen improvements.

[antikythera]

Thank you for the response. I work, and basically live on my computer, so it sees allot of use. I used to run trim once a week on Ubuntu, but noticed that I was having some I/O lag with the ssd. I switched over to daily trim since then and have seen improvements.

fair enough, which I/O scheduler were you using with ubuntu? I currently use mq-deadline with my notebook's SSD (manjaro x86_64 kernel 4.14.13)

[lsatenstein]

Hi norcal618

I run fstrim once a week from a crontab

This is my script

#!/bin/bash
# run fstrim either once/week or once/day not once for every reboot
# To run every other week, determine the week number using the 
# number of seconds since 1 Jan 1970, 
#
# use the date function to extract today's day number or week number
# the day number range is 1..366, weekno is 1 to 53 
#WEEKLY=0       #set to 0 for once per dau
WEEKLY=1        #set to 1 for once per week
#EEKLY=2        #set to 2 for every second week
lockdir='/scratch/dofstrim/lock/'          #you can replace with /root/lock if you only have 1 system installed.

if [[ $WEEKLY -eq 1 ]]; then
    dayno="$lockdir/dofstrim.weekno"
    number=$(date +%U)
else
    if [[ $WEEKLY -eq 0 ]]; then
        dayno=$lockdir/dofstrim.dayno
        number=$(date +%j)
    else
        if [[ $WEEKLY -eq 2 ]]; then
            number=$(date +%s)                  #seconds since
            number=$(expr $number / 604800 )    #weeks since 1/1/1970 (86400 * 7)
            echo "number of weeks since 1970/01/01 = $number"
            number=$(expr $number % 2 )         #remainder multiple of 2 weeks
            if [[ $number == 0 ]];then
                 echo "week number is even"
            else
                 echo "week number is odd"
            fi
            exit #decide what you want to do for every other week.
        fi
    fi
fi

prevval="000"

if [ -f "$dayno" ]
then
  prevval=$(cat ${dayno} )
else
   mkdir -p $lockdir
fi

if [  ${prevval} -ne ${number} ]
then
   sudo /sbin/fstrim -a
   echo $number    > $dayno
fi

For root's crontab, I have two entries.

@reboot /usr/local/bin/dofstrim.sh
@daily /usr/local/bin/dofstrim.sh

The dofstrim.sh writes the week number into a file
when it is invoked via @reboot or @daily, it obtains the current week number and compares it to the one on file.
If there is a change, the new week number is written to the file and the fstrim -a is executed.

If you also have a hard disk, you may want to consider moving /var from the SSD to a 4 gig partition on that hard disk. Most system tmp files are written to a subdirectory below /var. Some say to also relocate swap, but when I last checked, my swap file was only used if I did a suspend for the night, and a resume in the morning.

If you have 8 gigs ram, I was told that the suspend will write to a tmpfs (ram disk). I have a 128gig SSD for Fedora, I keep 15% (roughly 15gigs as an unallocated partition. That protects the SSD internals from thrashing (eg too soon reusing the same 4k page). My crontab entries and dofstrim.sh allows me to easily go 1 week between fstrim's.

Week=0 sets up a daily fstrim
Week=1 sets up a weekly fstrim
week=2 I left as future. It calculates a week number using seconds since Jan 1 1970

If you dual boot (more than 1 linux on your desktop), put the "lock" file to a directory common to both/all systems.
My /scratch/dofstrim/lock is common to my three Linux systems on my desktop. Does not matter from which I boot, fstrim is run only once per 7 days.

If you are using gnome then
test this

within ~/.config/autostart/dofstrim.sh

[Desktop Entry]
Type=Application
Name=fstrim to run weekly
Exec=/usr/local/bin/dofstrim.sh

Everytime you log in, the dofstrim.sh script is executed. To be honest, I did not as yet test this gnome autostart