I am using LUKS encryption with btrfs (Default Fedora partitioning layout) on Fedora Silverblue 41.
After a fresh/cold boot, GNOME System Monitor reported that 200MiB was written to disk just after login. (Resources tab > Disk > Total Written)
After 30 minutes of usage, System Monitor reported 6.5GiB was written to disk.
Checking the Processes tab and sorting by Disk Write Total, I only saw firefox-bin with 890MiB written, alongside processes with some miniscule writes (<50MiB), in total not crossing 1.2GiB.
As my install is on a SSD, this makes me extremely concerned about the longevity of my SSD.
Attached pictures to clarify the issue.
I used the Resources app from Flathub and it reports far lower disk total write, this might be an issue with GNOME System Monitor’s total disk write reporting.
Although Resources’s reporting is for the SSD only, whereas System Monitor’s reporting is for “Disks”, which implies reposting writes to ALL storage devices, I don’t have any other external drives or SSDs connected, thus the logical assumption is that it only reported writes to the SSD.
You can use smartctl -x /dev/XXX to see what is actually written to the drive.
Also note that there are tmpfs file systems that are in RAM that maybe in the counts.
But I agree it seems high.
It would seem that Firefox has downloaded a lot of data.
Did you download some big files?
Here is a snipit of that I see from sudo smartctl -x /dev/nvme1
smartctl 7.4 2023-08-01 r5530 [x86_64-linux-6.13.5-200.fc41.x86_64] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Number: Samsung SSD 980 1TB
...
SMART/Health Information (NVMe Log 0x02)
...
Data Units Read: 65,627,696 [33.6 TB]
Data Units Written: 24,569,522 [12.5 TB]
...
Thank you for the reply.
It appears that smartctl is not installed by default on Fedora Silverblue, and I don’t think smartctl can’t help here, as I was discussing Total Disk Write after the fresh boot, for this “session” only, whereas S.M.A.R.T. data shows you total writes for the drive’s entire lifetime (as in, total amount of data written irrelevant of OS or session)
I did not download anything using Firefox, I just browsed this forum and watched some Youtube videos.
1GiB of writes would still be reasonable over a couple of hours, but my current writes are nearing 3GiB (I’ll be using Resources from now on as it provides device-specific statistics)
What it can do is give you the actual writes done to your SSD.
Which that information you can confirm if the monitor is reliable.
I don’t use atomic install, but you can install RPMs on top of silverblue, I just don’t know the commands to use.
I have seen advice about doing that in other posts.
I overlayed smartmontools and confirmed that data is indeed being written to it.
On boot:
Data Units Written: 33,087,673 [16.9 TB]
After a while :
Data Units Written: 33,088,203 [16.9 TB]
Here, 33087678÷(16.9×1024) = 1911.96
So each MiB of data roughly corresponds to 1912 “Data Units” according to the smartctl information.
Thus, the difference between them is 530 “Data Units”, or about 0.25 MiB, which is odd.
However, running sudo awk '/nvme/ {print $3"\t"$10 / 2 / 1024}' /proc/diskstats to process the /proc/diskstats file directly gives me 557.743 (MiB), which is close to what Resources reports, whereas GNOME System Monitor reports 1.7GiB. Thus the GNOME System Monitor reporting is either flawed or it also includes tmpfs and other sources.
Edit : It could also be that btrfs compression and linux’s write caching behaviour are lessening the impact of writes on the SSD itself, which is not reflected in /proc/diskstats data.
Edit2 : I have also been monitoring writes using iotop -aP and it seems like almost 1/3 of all the writes are being done by firefox, 1/3 by btrfs-transaction and 1/3 by other miscelleneous sources.
Can you explain the firefox writes from your browsing?
Maybe some of the tabs you have open are on websites that want to save data locally?
