Question about mint 20.X installation medium

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pauljames77
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Question about mint 20.X installation medium

Post by pauljames77 »

- Why does the mint 20.X installation medium (external hard drive) get split into two disks after you boot into it, and shut down?

- It gets split into disk 1: Linux Mint 20.X [Desktop X-bit], and disk 2: Writable
Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 1 time in total.
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xenopeek
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Re: Question about mint 20.X installation medium

Post by xenopeek »

Do you mean while booted from the ISO or from an actual installation of Linux Mint?

Where are you seeing the 2 disks -- add a screenshot of that. If the image is too large you can upload on image hoster like imgbb.com or imgur.com (both can be used without or with account; with account you can opt to delete the images later) and share the link to the uploaded image here.
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Jo-con-Ël
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Re: Question about mint 20.X installation medium

Post by Jo-con-Ël »

Yes this is something I noticed before when creating Linux Mint 20.2 Live USB using Mint's tool (USB image writer) from Linux Mint 20 Ulyana installed in UEFI mode.

It surprised me as Linux Mint tool gives no option to create persistence.
Screenshot from 2021-12-06 11-14-46.png
By default It creates two partitions, one with Linux Mint 20.X and a second FAT/EFI one. Rest of space available on USB is recognized as non partition but free space.
Screenshot from 2021-12-06 11-15-35.png
But once you booted with Live USB that free space becomes and remains as a third writable partition.
Screenshot from 2021-12-06 10-32-02.png
It is auto-mounted, when booting Live USB, as /var/log to store Install-logs for that session with a crash(empty in my case) and a log folder.

Code: Select all

ls /media/jo-con-el/writable/install-logs-2021-12-06.0/log
auth.log         mintsystem.log
boot.log         mintsystem.timestamps
btmp             private
casper.log       syslog
cups             ubuntu-system-adjustments-adjust-grub-title.log
dmesg            ubuntu-system-adjustments-start.log
gpu-manager.log  ubuntu-system-adjustments-stop.log
kern.log         wtmp
lastlog          Xorg.0.log
lightdm
It is formatted in Ext.4 as you can see and owned by root so hardly can be used as "normal" storage space for users w/o doing something else.

First time I noticed was creating LM 20.2 XFCE Live USB and also happened with LM 20.2 Cinnamon ISO (images). I've never read anything about it and I didn't notice before maybe 'cause I use other tools. not mintstick. Gonna try creating an LMDE 4 Live USB (also when I can anothers with LM 20 and 20.1) from LM 20.2 XFCE to see if it is the same.

PD1: No, it doesn't happen with debbie.

PD2: Also happens with LM20.X iso when creating Live USB from LM 19.1, 20 and 20.2.

PD3: Neither it happens with LM 19.X ISOs so that "feature" is only available when creating LM 20.X Live USBs because of their ISO image contents.

PD4: I thought it would happen only using dd based tools as mintstick GUI but I was wrong . It does happen also with unetbooting,Multisystem, ballena-etcher...if there' s free space (not allocated) left out of the FAT32 partition when creating Live USB.That unallocated space will be used as writable partition once booting Live USB (at least in UEFI mode).

Here fdisk results (sde2 is that writable partition)

Code: Select all

Disk /dev/sde: 3.75 GiB, 4009754624 bytes, 7831552 sectors
Disk model: STORE N GO      
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x0001c416

Device     Boot   Start     End Sectors  Size Id Type
/dev/sde1  *       2048 4718591 4716544  2.3G  c W95 FAT32 (LBA)
/dev/sde2       4718592 7831551 3112960  1.5G 83 Linux
And it it shown also in inxi results (obviously first partition size is wrong)

Code: Select all

mint@mint:~$ inxi -P
Partition:
  ID-1: / size: 7.78 GiB used: 78.4 MiB (1.0%) fs: overlay source: ERR-102 
  ID-2: /var/log size: 1.43 GiB used: 5.0 MiB (0.3%) fs: ext4 dev: /dev/sde2
PD5: That wirtable partiton can be used as persistence on next boots easyly. You only need to add persitent to kernel line on each boot.
(Edited)
Last edited by Jo-con-Ël on Tue Mar 08, 2022 10:44 am, edited 14 times in total.
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pauljames77
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Re: Question about mint 20.X installation medium

Post by pauljames77 »

- I will post a screenshot of the external hard drive under the NEMO file manager later.

- Yes, the "writable" disk/partition contains log file directories.
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Jo-con-Ël
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Re: Question about mint 20.X installation medium

Post by Jo-con-Ël »

Finaly, also booting Linux MInt Live USB created with those iso files (LM 20.X) in BIOS mode it happens to create that writable partition with unallocate space on USB.
Linux Live USB creted with Unetbootin with only one FAT32 2,4 GB partition.
Linux Live USB creted with Unetbootin with only one FAT32 2,4 GB partition.
Booting that live USB in BIOS mode.
Booting that live USB in BIOS mode.
So the only way to prevent this happen is creating USB live with no unallocated space on it (with Rufus, Unetbootin,...by example).
Live USB created with Rufus. No unallocated space allowed if using ISO writing method (not dd).
Live USB created with Rufus. No unallocated space allowed if using ISO writing method (not dd).
Using LM tool it is not possible but once you have made Linux Live USB you will be able to create another partition for storage propose (FAT/NTFS/...) with unallocated space using Disks or Gparted...before booting Linux Mint Iive USB.

I will try to create an USB with persistence partition next time...
Last edited by Jo-con-Ël on Sun Feb 27, 2022 1:01 pm, edited 8 times in total.
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pauljames77
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Re: Question about mint 20.X installation medium

Post by pauljames77 »

Did you use the "USB Image Writer" app to create the installation medium only on the 19.1 release of mint 19?
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Jo-con-Ël
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Re: Question about mint 20.X installation medium

Post by Jo-con-Ël »

pauljames77 wrote: Mon Dec 06, 2021 9:05 pm id you use the "USB Image Writer" app to create the installation medium only on the 19.1 release of mint 19?
No, I said I've used Linux Mint USB Image Writer from LM 19.1, LM 20 and LM 20.2 (see PD2 on previous post). Also I've used Unetbootin (last try) and previously Multisystem and Rufus (Windows).

PD: I've created a persistence Live USB with Rufus (persistent casper-rw partition) and another one with Unetbootin. They both work as expected if no unallocated space is left booting in UEFI mode. Rufus can't leave unallocate space or create casper-rw file. Unetbootin persistent Live doesn't work booting in UEFI mode (never did before but never tried writing persistent parameter editing first boot option on its grub menu), work as expected in BIOS mode with casper-rw partition and leaving unallocated it is omited.

Using casper-rw file and leaving unallocated space, casper-rw file is not used, only writable partition created on booting.

Most probably changes introduced in casper from Ubuntu 19.04/19.10 are responsible of this issue/feature.
Last edited by Jo-con-Ël on Thu Jan 13, 2022 6:57 pm, edited 1 time in total.
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gmk57
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Re: Question about mint 20.X installation medium

Post by gmk57 »

Jo-con-Ël wrote: Mon Dec 06, 2021 5:22 am But once you booted with Live USB that free space becomes and remains as a third writable partition.
Thanks for the info! I found this partition on Mint 20.2 drive, run chmod 777 and used it as a general-purpose portable storage (modern flash drives have much more space than Mint image needs), but didn't know it was created on first boot. So I was wondering why it's missing after writing Mint 20.3 image, and stumbled upon this thread. :)
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Jo-con-Ël
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Re: Question about mint 20.X installation medium

Post by Jo-con-Ël »

I didn't try it before because i use to use another tools as I said ( Unetbootin, multisystem,..) so I can create a deditated tpartion for storage (personal data is the most important thing) with a more useful filesystem for external media as NTFS or FAT32.

Now I've tried, and need to warning about result.

I've changed permission (sudo chown /media/jo-con-el/writable), created a folder inside writable partition with few files on it and removed all the rest. No problems. Then booted live USB:

1)Booting Live USB as default you can not access those data from Live session because writable partition will be mounted as /var/log. No problems when shutting down. Then, from installed system, Data can be accessed by user and also the new log folder (as root).

2)When trying to use writable partition as permanence (with persistent parameter editing default entry on booting) writable partition is used as persistence and can be accessed an it shows previous logs and persistent folders (upper and work) but there is no /writable/DATA folder.
I thought DATA folder was removed but no. It was on filesystem root and also included in writable partition>upper>DATA.
Image
That would be the cause of the problem when trying to shutdown. I received few I/O errors, warnings with certain blocks/flags and Live system hangs on unmounting so need to use Alt+PrintScrn SUO.

Then, booting my installed system I checked writable partition filesystem and it was "intact", browse inside writable partition and see what happened. The folder with my personal files (DATA) is still on writable partition but was finally moved inside upper folder. :shock:

My DATA folder is still owned by user even upper is owned by root.
Screenshot from 2022-01-14 22-15-42.png
3)Booting Linux Live with persistence again it is still there and I can shutdown w/o problems. Also new folder logs are created when booting Live as normal.
Image
In resume, I will keep on using another tool as Unetbootin to create Live USB if I'm going to use it for whatever propose but installing (as installation media), so I can make a dedicated partition for persistence and another one as external storage (personal data is the most important). :wink:
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