Cloudshell XU4 SSD and trim

I have a Cloudshell with 240 GB Crucial BX200 SSD - do I need to worry about trim?

On an SSD equipped BananaPi (OS is most recent Bananian 16.04 r01) I run this script in cron.daily:

echo “*** $(date -R) ***” >> $LOG
fstrim -v / >> $LOG

When I use this on the XU4 I get the message " the discard operation is not supported". The log just states the date. On the BananaPi it tells you how many bytes were trimmed.

I don’t know much about this so any help appreciated.

Hi John,

Just wondering if you need to add the “discard” option to filesystem mount options in /etc/fstab

/dev/MyRootFilesystem  /               ext4    defaults,noatime,discard

Either way, can you possibly paste the results of the following on both your XU4 and BPi so I can compare:

cat /etc/fstab

Here’s the fstab files. Not much in the Bpi one. It boots from the SD and the files system is on an SSD and neither appear in the fstab but I don’t claim to fully understand this.

BPi fstab


512 MB swapfile

/swapfile1 swap swap defaults 0 0 /mnt/pi nfs rsize=8192,wsize=8192,timeo=14,intr 0 0 /mnt/Multimedia nfs rsize=8192,wsize=8192,timeo=14,intr 0 0

XU4 fstab

proc /proc proc defaults 0 0
UUID=96C3-9298 /boot vfat defaults,noatime,discard 0 2
UUID=ff31ef97-52c2-4ac4-95c8-20e0d3ca064f / ext4 defaults,noatime,discard 0 1 #SSD

UUID=7f7a5a95-abd7-4360-8141-74a5199bdfba /mnt/usb_1 ext4 defaults,noatime,nofail 0 0 #USB flash drive

tmpfs /tmp tmpfs defaults,noatime,nodev,nosuid,mode=1777 0 0
tmpfs /var/log tmpfs defaults,size=20m,noatime,nodev,nosuid,mode=1777 0 0
tmpfs /DietPi tmpfs defaults,size=10m,noatime,nodev,nosuid,mode=1777 0 0 /mnt/pi nfs rsize=8192,wsize=8192,timeo=14,intr 0 0 /mnt/Multimedia nfs rsize=8192,wsize=8192,timeo=14,intr 0 0

Thanks for your help with this.

Hi John,

Yep, same issues on my XU4 with EMMC and usb drive.

Did some Googling, looks like it might be a XU3/4 specific hardware “issue” or missing feature. Could even be kernel is missing a setting, but unsure at the moment:

XU4 EMMC, sda is 500GB Hitachi platter (No trim support):

root@DietPi-XU4:~# cat /sys/block/mmcblk0/queue/discard_max_bytes
root@DietPi-XU4:~# cat /sys/block/sda/queue/discard_max_bytes


root@DietPi:~# cat /sys/block/mmcblk0/queue/discard_max_bytes

RPi 3 (seems my 32GB USB pen drive doesnt support trim):

root@DietPi:~# cat /sys/block/mmcblk0/queue/discard_max_bytes
root@DietPi:~# cat /sys/block/sda/queue/discard_max_bytes

Thanks to you John :slight_smile::
I’am adding a cron.daily TRIM for DietPi v121. Won’t work for XU4 (yet), but other devices using flash memory should benefit from it:

This will trim all capable drives (via a list of all mount points):

	#TRIM drives (all mount points)
	df -P | awk '{print $6}' | tail -n +2 > /tmp/.dietpi-cron-daily_trim

	echo -e "$(date)\nDietPi Cron Daily | Filesystem trim"
	while read -r line
		fstrim -v "$line" >> /var/log/dietpi_cron_daily_trim.log

	done < /tmp/.dietpi-cron-daily_trim
	rm /tmp/.dietpi-cron-daily_trim

	cat /var/log/dietpi_cron_daily_trim.log

Great thanks having just upgraded to 120 (all good so far) I’m looking forward to 121.


Hi Fourdee,

Up to 122 - thanks for the update. I have just tried the trim script and the result is the same - " the discard operation is not supported".

Any ideas?

Hi John,

Unfortunately, not at the moment.
Its either a XU4 hardware limitation, or, a possible kernel feature for TRIM/discard is disabled. Unsure.

I’ve created a post on the Odroid forum to ask Meveric this question, if anyone knows, he will: