I have the following disk setup, a dual-boot with Windows 10 and Linux Mint 19.3:
NAME LABEL SIZE FSTYPE MOUNTPOINT UUID
sda 477G
├─sda1 100M vfat /boot/efi AE89-82D6
├─sda2 16M
├─sda3 WINDOWS-C 476.3G ntfs A4DC8D83DC8D508A
└─sda4 505M ntfs BE1AB9201AB8D69D
sdb 1.8T
├─sdb1 1G ext2 /boot c360756e-9335-476d-889c-e10026a48c77
├─sdb2 LINUX-HOME 500G ext4 /home 96ce746c-1934-4774-88df-c9c132604795
├─sdb3 LINUX-BACKUP 1.2T ext4 /media/Backup-Data 36e45e26-751e-45d8-85b3-e4956829b821
├─sdb4 80G btrfs /mnt/timeshift/backup a2d7fadb-ca2a-4ac6-b4cf-4d1ff0c3f693
└─sdb5 16G swap [SWAP] 93b4b3b4-d3b4-4af6-8a12-e34b26bbe391
The only filesystem that is mounted by both systems at bootup is the EFI partition.
After reading about the SSD optimization bug in Windows 10 v2004, I disabled it but ran it manually once (on 8/31/20). When I next rebooted into Linux, it was due for its weekly fstrim. I checked the logs and found these entries:
$ journalctl -u fstrim.service
-- Logs begin at Sun 2020-08-23 18:36:10 PDT, end at Tue 2020-09-01 16:28:51 PDT. --
Aug 24 08:23:19 dss-mint systemd[1]: Starting Discard unused blocks...
Aug 24 08:27:29 dss-mint fstrim[1101]: /home: 406.1 GiB (436010364928 bytes) trimmed
Aug 24 08:27:29 dss-mint fstrim[1101]: /media/Backup-Data: 979.6 GiB (1051850047488 bytes) trimmed
Aug 24 08:27:29 dss-mint fstrim[1101]: /boot/efi: 63.9 MiB (66948096 bytes) trimmed
Aug 24 08:27:29 dss-mint fstrim[1101]: /boot: 838.4 MiB (879099904 bytes) trimmed
Aug 24 08:27:29 dss-mint fstrim[1101]: /: 72.1 GiB (77447188480 bytes) trimmed
Aug 24 08:27:29 dss-mint systemd[1]: Started Discard unused blocks.
-- Reboot --
Aug 31 08:25:36 dss-mint systemd[1]: Starting Discard unused blocks...
Aug 31 08:29:03 dss-mint systemd[1]: fstrim.service: Main process exited, code=killed, status=15/TERM
Aug 31 08:29:03 dss-mint systemd[1]: fstrim.service: Failed with result 'signal'.
Aug 31 08:29:03 dss-mint systemd[1]: Stopped Discard unused blocks.
Not finding anything on these messages, I reran the service and everything reported OK. Should I be excluding the EFI partition from one or the other system? Is this the reason why the run on the 31st did not complete? There are no disk errors (as reported by Gnome Disks Smart tests).
UPDATE #1: I checked output from the fstrim.timer unit, and it doesn't seem to detect that the fstrim.service unit ever finishes; the only shutdown is caused by a reboot (8/23/2020 is the date the system was installed):
$ journalctl --no-pager -u fstrim.timer
-- Logs begin at Sun 2020-08-23 18:36:10 PDT, end at Wed 2020-09-02 09:50:35 PDT. --
Aug 23 18:36:10 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 18:45:59 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
Aug 23 18:45:59 dss-mint systemd[1]: Stopping Discard unused blocks once a week.
Aug 23 18:45:59 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 18:46:00 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
Aug 23 18:46:00 dss-mint systemd[1]: Stopping Discard unused blocks once a week.
Aug 23 18:46:00 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 18:51:30 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 23 18:51:57 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 19:23:18 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 23 19:23:47 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 19:26:24 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 23 19:26:52 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 19:38:32 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 23 19:39:05 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 19:44:21 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 23 19:44:58 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 19:46:04 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 23 19:46:34 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 23 20:20:20 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 24 08:23:19 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 24 14:02:00 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 24 14:05:17 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 24 19:13:32 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 25 06:40:55 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 25 19:46:07 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 26 08:26:55 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 26 10:57:15 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 26 10:57:43 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 26 11:28:42 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 26 11:29:19 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 26 18:05:41 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 26 18:56:28 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 26 18:59:27 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 27 08:40:46 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 27 17:32:46 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 28 06:59:36 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 28 19:05:33 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 29 08:18:49 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 29 19:05:01 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 30 08:55:41 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 30 19:03:48 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 31 08:25:36 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 31 08:29:03 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Aug 31 08:29:35 dss-mint systemd[1]: Started Discard unused blocks once a week.
Aug 31 19:24:53 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Sep 01 08:20:41 dss-mint systemd[1]: Started Discard unused blocks once a week.
Sep 01 19:12:46 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Sep 02 07:11:27 dss-mint systemd[1]: Started Discard unused blocks once a week.
Sep 02 09:33:51 dss-mint systemd[1]: Stopped Discard unused blocks once a week.
-- Reboot --
Sep 02 09:34:20 dss-mint systemd[1]: Started Discard unused blocks once a week.
