Hi everyone,

I discovered a little trixk that will help keep a SSD clean and maintained under Linux.

I ran "fstrim -av".

===
When you delete a file on a normal filesystem, the OS just marks the space as "free," but the SSD itself doesn't know that. From the SSD's point of view, those blocks still look occupied.

fstrim sends a message to the SSD saying:

"These blocks are no longer in use -- you can wipe them internally whenever you want."

That lets the SSD:

clean up unused blocks

prepare them for fast future writes

reduce write amplification

maintain long-term performance
===

My result?

I freed up 406GB of space on a 512GB SSD.

The speed-up was immediately noticable.

-- Sean

... Mary had a little RAM; only about a meg or so.
--- MultiMail/Linux
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Hello Sean!

On 25 Jan 2026, digimaus said the following...

I discovered a little trixk that will help keep a SSD clean and
maintained under Linux.

I ran "fstrim -av".

Yep, that's a nice command!

On my Debian system there's a "util-linux" package which contains the fstrim utility as well as a systemd timer (fstrim.timer), which one can enable make it run weekly.

I was also amazed at how much space is "freed". I guess temporary logs and stuff contribute a lot to this...

Best regards
Zip

--- Mystic BBS v1.12 A49 2024/05/29 (Linux/64)
* Origin: Star Collision BBS, Uppsala, Sweden (618:500/27)

Zip wrote to digimaus <=-

I was also amazed at how much space is "freed". I guess temporary logs
and stuff contribute a lot to this...

I was shocked to see how much room was freed. I need to run this on my little Dell laptop as it has a 128 GB mSATA drive in it that would benefit from this.

Well, maybe not. I do want to encrypt the drive using LUKS here soon so I'll do that after I reinstall Slackware.

Either way, nice to know. FreeBSD has special utilities to run on SSDs to not write to them as much to extend the drive's lifetime.

-- digi <8D~

... She got the goldmine; I got the shaft.
--- MultiMail/Linux
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Hello Sean!

On 26 Jan 2026, digimaus said the following...

I was shocked to see how much room was freed. I need to run this on my little Dell laptop as it has a 128 GB mSATA drive in it that would
benefit from this.

Yep, that could probably make quite some difference!

Either way, nice to know. FreeBSD has special utilities to run on SSDs
to not write to them as much to extend the drive's lifetime.

I used to increase the "commit" value for ext4 file systems on my Debian box... But to lower the chances of losing data in case of power interruptions (brownouts, outages etc.) I actually skipped doing that some time ago, as the TBW values and the age of the SSD indicated that the disk should hold up for another 75 years or so anyway. :-D

Best regards
Zip

--- Mystic BBS v1.12 A49 2024/05/29 (Linux/64)
* Origin: Star Collision BBS, Uppsala, Sweden (618:500/27)