Automatic TRIM vs. manual TRIM
- by Eike Cochu
I am currently trying to find out how to trim with my new TP and was wondering about the difference of manual/online trimming.
Here is my setup:
ThinkPad T430s with SSD Samsung 830, 128GB and Xubuntu 12.10, here are some outputs to check if trim will work on my system (got these from here: http://wiki.ubuntuusers.de/SSD/TRIM)
root@eike-tp:~# sudo hdparm -I /dev/sda | grep -i TRIM
* Data Set Management TRIM supported (limit 8 blocks)
First, I tried the online trimming: How to enable TRIM?
my fstab with discard inserted:
UUID=d6c49c17-a4f1-466c-9f7e-896c20db3bba / ext4 discard,noatime,errors=remount-ro 0 1
# swap was on /dev/sda5 during installation
UUID=a0322f5f-c6c1-4896-863f-668f0638d8cf none swap sw 0 0
tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0
I tried to test if it works (but I don't get any zeroes when I try it with /dev/sda), but found out that this method is only possible with SSD type 2 and I seem to have type 3. So I don't know if it works or not.
The Ubuntuwiki (first link) recommends manual trimming, so I set up a daily cronjob instead of discard:
#!/bin/sh
LOG=/var/log/batched_discard.log
echo "*** $(date -R) ***" >> $LOG
fstrim -v / >> $LOG
the wiki article suggests weekly or daily. Now to my questions:
How often executes the automated trim?
How often is recommended?
Online vs. manual trimming?
Thank you for your help
