When I log in to my main Ubuntu-MATE 20.04.3 (nvme0) OS, my secondary OS install (/dev/sda) is somehow already auto-mounted on the desktop.
I'd like it not to be.
/dev/sda is an internal SSD on which I also have a bootable Ubuntu-MATE 20.04.3 installation.
In my top panel, I've placed the "Disk Mounter" applet, (put there by right-clicking on the top panel and choosing "Add to Panel." Disk Mounter is one of the many applets that users can put in the panel).
Via Disk Mounter, I have a disk-icon in the top panel that I can click on to mount another internal SSD that is for storage only.
Normally I should also have a second, identical-looking disk-icon there right beside it to click on that mounts the /dev/sda SSD.
In fact, I do have that second disk-icon for /dev/sda, but for some reason it's oversized -- larger (in fact, it's a different icon) than the one beside it, and it has the small lime-green triangle lit up below it, indicating that the /dev/sdadrive is already mounted (until I unmount it).
This is on a desktop workstation running (as indicated above) Ubuntu-MATE 20.04.3, kernel 5.4.0-96-generic.
Here is my /etc/fstab file:
(UUID 07041... is the main OS's ext4 partition, and UUID 2BD2... is the main OS's EFI partition)
1 # /etc/fstab: static file system information.
2 #
3 # Use 'blkid' to print the universally unique identifier for a
4 # device; this may be used with UUID= as a more robust way to name devices
5 # that works even if disks are added and removed. See fstab(5).
6 #
7 # <file system> <mount point> <type> <options> <dump> <pass>
8 UUID=07041e0f-1cde-4caf-9b1d-86851e9601ed / ext4 errors=remount-ro 0 1
9 /swapfile none swap sw 0 0
10 UUID=2BD2-4199 /boot/efi vfat defaults 0 1
And here is the output of:
--> lsblk -e 7 -o name,fstype,size,fsused,label,partlabel,mountpoint,uuid,partuuid pts/2 Tuesday 2022-01-25 14:29:20
NAME FSTYPE SIZE FSUSED LABEL PARTLABEL MOUNTPOINT UUID PARTUUID
sda 894.3G
├─sda1 vfat 550.3M SSD_ESP ssd_EFI-system-partition 6DE5-0FF8 684141f2-20c3-41be-b2c4-7058d9488896
└─sda2 ext4 893.7G 20.04.3-ssd UbuntuMATE-20.04.3 21697ef7-83e3-4414-a859-91841f61dce8 7cc6f822-eb23-4829-9039-6d09e6e0ca55
sdb 894.3G
└─sdb1 ext4 894.3G WeirdBeard WeirdBeard 70e15e24-a75c-4115-9c83-29cb585676f6 5ab70820-78e7-466e-9c0f-101054d5df9b
nvme0n1 931.5G
├─nvme0n1p1 vfat 402M 9.7M NVME0_ESP nvme0_EFI-system-partition /boot/efi 2BD2-4199 337ce8d2-65a0-4051-8c12-55cc22666e7e
└─nvme0n1p2 ext4 931.1G 40G 20.04.3-nvme0 UbuntuMATE-20.04.3 / 07041e0f-1cde-4caf-9b1d-86851e9601ed 0657b873-53c2-4a40-9e60-3b26c891fd1b
nvme1n1 931.5G
├─nvme1n1p1 vfat 402M NVME1_ESP nvme1_EFI-system-partition E23B-29C2 90af4214-eca8-4265-8e5f-9c2e3301bba9
└─nvme1n1p2 ext4 931.1G EMPTY-nvme1 The-next-LTS-UbuntuMATE a3cb2757-686f-4c5c-92ca-a43b3a223207 77706804-715d-4276-9824-a184ed00df4f
(sdb1 -- "WeirdBeard" -- is the storage drive; nvme1 is empty at the moment. They can both be ignored.)
(I tried the answer posted here (from 2014) -- it prevented the auto-mount, but this only made it so I couldn't mount /dev/sda at all.)
One problem that I'm not sure what to do about is that the /dev/sda drive, after a few minutes, reverts (on its own) to being mounted at /run/timeshift/backup (that is, if I don't leave it mounted on the desktop).
sudo timeshift --check shows:
/dev/sda2 is mounted at: /run/timeshift/backup, options: rw,relatime,stripe=8191
So: sda2 is always either
(a) mounted upon login at /media/<myusername>/20.04.3-ssd <-- (the label I gave this partition) until I un-mount it;
(b) mounted at /run/timeshift/backup; (during which time its icon does not appear in the top panel) or
(c) not mounted.
My question: How can I get the /dev/sda drive to NOT automount at login (but TO mount when I click its icon in the panel), and how can I get the top-panel icon uniform with, and same size as, the other disk-icon there?
