ssd trim <Answered>

[old_guy]

I just installed an ssd. I have my os on the ssd and my data on a hd. I read that you should run trim for the ssd and found that MX has fstrim-mx in /etc/cron.weekly. I don't keep my system on all the time and don't know when/how cron runs, so my question is how should I run trim (fstrim-mx) on my machine?

Earl

[fehlix]

I just installed an ssd. I have my os on the ssd and my data on a hd. I read that you should run trim for the ssd and found that MX has fstrim-mx in /etc/cron.weekly. I don't keep my system on all the time and don't know when/how cron runs, so my question is how should I run trim (fstrim-mx) on my machine?

Earl

Cron.weekly might be smart enough to run when it's over due.
Not sure how long you have to powered on the system to get trim triggered.
You'll find the run-log here:
/var/log/trim.log

I do actually prefere do have it run a bit more often.
It's more important, when you have not much space on the device left.

[chrispop99]

If trim is started by cron.weekly, it will be logged in var/log/trim.log.

I would suggest having a look in that log a month or so and see if a trim operation has occurred. If that wasn't the case, you could use cron.daily instead, but I think that would be overkill.

If you want to do it manually, execute this in a terminal as root:

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fstrim / -v

Chris

[fehlix]

Another note regarding trim:
You might verify or double check your /etc/fstab having noatime mount options enabled on the ssd-partions.
I do also prefere not to enable continuous trim with mount discard option.
And last but not least, do verify that your ssd does support trim at all by running this command

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lsblk --discard

and check that the "DISC-GRAN" column is non-zero for your ssd-drive.
( fstrim might be smart enough not to harm you ssd, even when the ssd would not support trim. But better check twice ;=)

[chrispop99]

fstrim might be smart enough not to harm you ssd, even when the ssd would not support trim. But better check twice

I had some early SSD's that didn't support trim, and if you tried, trim refused to run.

As you say, no harm in checking though.

Chris

[chrispop99]

With regard to noatime, I used to add that to earlier SSD's, but their lifespan is so high now that I don't bother. I don't use swap however, and set swappiness to 1.

Chris

[old_guy]

Thanks All

I'm checking all the suggestions and will accept any more. Looking online much info is more than a few years old. What I got was a Samsung 860 EVO 500GB. I partitioned it to hold several OS's and have a 4TB HD for data. Still sorting things out.

I won't close this out just now. See if any more tips come in.

Earl

[fehlix]

I'm checking all the suggestions and will accept any more. Looking online much info is more than a few years old. What I got was a Samsung 860 EVO 500GB. I partitioned it to hold several OS's and have a 4TB HD for data. Still sorting things out.

Despite Samsung promising longlive time and having pre-reserved internal "overprovisioning" spare/free unused areas,
I would still leave about 5 -10 GB space of the drive empty (unassigned), e.g. at the "end" of the drive.
Simply as the technique to free up "marked-as-free" blocks is still the same. And you do good for the ssd if it does have for it's internal re-shuffling of blocks during freeing-up enough unused space, otherwise it needs to rewrite/reshuffel used blocks,
which increases unneeded internal write operations.
Similar strategy with "noatime": It avoids unnecessary write operations onto the file-systems, i.e. on the ssd.

[chrispop99]

Since kernel 2.6.30 the default state is relatime. This reduces writes significantly whilst still providing a degree of time-stamping.

Even without noatime, the likely life of a modern SSD is much longer than the hardware around it, and significanly longer than a spinner.

Chris

[sunrat]

I have never needed to check atime on my personal computer so always set noatime anyway. Modification times are still written whenever a file changes.
Weekly fstrim is the main thing for SSD optimisation.