Its not easy to determine how to skip the filesystem check

Bug #1875548 reported by C.S.Cameron
34
This bug affects 6 people
Affects Status Importance Assigned to Milestone
casper (Ubuntu)
Fix Released
Undecided
Unassigned

Bug Description

I see that Live Ubuntu 20.04 is plagued by disk checking on boot.

Not just with Live USB but with Persistent USB also.

If not fast enough to cancel with ctl-c it starts on filesystem.squashfs and runs until over 90% complete.

Very irritating. There have been quite a few complaints on Ask Ubuntu already.

If it was just a run once it would not be so bad.

Is there some way to get rid of this or is it a bug we have to live with?

Perusing Ask Ubuntu everyday for many years I have never seen anybody ask for such a feature.

A run once filesystem check might have its uses on a Live installer drive but is not needed on a Persistent utility drive.

The only alternative I see is to use a Full install USB drive were automatic disk checking is not run.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-release-upgrader-core 1:20.04.18
ProcVersionSignature: Ubuntu 5.4.0-26.30-generic 5.4.30
Uname: Linux 5.4.0-26-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CasperVersion: 1.445
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Tue Apr 28 06:07:32 2020
LiveMediaBuild: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
Symptom: dist-upgrade
UpgradeStatus: No upgrade log present (probably fresh install)

Revision history for this message
C.S.Cameron (cscameron) wrote :
Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in ubuntu-release-upgrader (Ubuntu):
status: New → Confirmed
Revision history for this message
sudodus (nio-wiklund) wrote :

I can confirm this bug. It appeared with Focal Fossa (does not affect previous versions).

I suggest to store a small file in the partition with the label 'writable' or 'casper-rw', that tells the system that the live USB disk check has been performed, and is no longer necessary.

Revision history for this message
Brian Murray (brian-murray) wrote :

I believe you can use the following kernel command line option to skip the filesystem check and that would be a better solution.

fsck.mode=skip

affects: ubuntu-release-upgrader (Ubuntu) → casper (Ubuntu)
summary: - Live USB disk check
+ Its not easy to determine how to skip the filesystem check
Revision history for this message
sudodus (nio-wiklund) wrote :

@ Brian Murray,

That is a good idea. I tested and it works with Focal Fossa :-)

What happens when we use the boot option 'fsck.mode=skip' for older versions of Ubuntu (for example 18.04 LTS)? Will it cause some error or simply be ignored?

Revision history for this message
C.S.Cameron (cscameron) wrote :

The line "Checking disks: 0% complete" still comes up but **fsck** does not run, and boot time is not increased, very good.

Revision history for this message
sudodus (nio-wiklund) wrote :

After testing older versions of Ubuntu, it seems that 'fsck.mode=skip' is simply ignored, and does not create any problem. So I have included it in some of the menu entries for persistence and 'live-only to RAM' created by mkusb version 12.4.7.

tags: added: id-5ea8876742d85332d7b138bb
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package casper - 1.447

---------------
casper (1.447) groovy; urgency=medium

  [ Matthieu Clemenceau ]
  * Updated cmdline options in casper manpage documentation. LP: #1875548

  [ Michael Hudson-Doyle ]
  * Add interactive network configuration.

  [ Dimitri John Ledkov ]
  * Fix up interactive network configuration default ISO urls to be more
    dynamic.
  * In groovy, live-cds now have ssl support in busybox

  [ Erich Eickmeyer ]
  * Add Ubuntu Studio Calamares Installer as trusted

 -- Dimitri John Ledkov <email address hidden> Sat, 23 May 2020 03:57:20 +0100

Changed in casper (Ubuntu):
status: Confirmed → Fix Released
Revision history for this message
C.S.Cameron (cscameron) wrote :

I ran:

sudo apt-get update
sudo apt-get install -y casper

And got, "casper is already the newest version (1.334)".
Am I doing something wrong?

Revision history for this message
sudodus (nio-wiklund) wrote :

1. Maybe the bugfix is only addressing Groovy, which has casper 1.447 now.

2. It seems that the bugfix is only an update of the casper manpage because the integrity check is still there for persistent live systems unless I add the boot option

fsck.mode=skip

(tested in Lubuntu Groovy).

Revision history for this message
C.S.Cameron (cscameron) wrote :

Oops, casper - 1.334 was for 18.04.
With 20.02 I get: "casper is already the newest version (1.445)".
Hopefully 1.447 will be working with 20.04 soon, this is the version the bug is written about.

Revision history for this message
Jay Michael (jmichael-ll) wrote :

Ubuntu 20.04.1 performs the disk check when booted from an ISO.
"fsck.mode=skip" does *not* prevent the disk check.

Revision history for this message
Jay Michael (jmichael-ll) wrote :

Ubuntu 20.04.2 behaves the same way.

"quiet" kernel parameter seems to enable skipping the disk check: With "quiet" on the kernel command line, one of the few lines to appear on the screen is "disk check skipped", and the boot completes noticeably faster. (35s instead of 55s, booting from an ISO file on a hard disk)

Revision history for this message
C.S.Cameron (cscameron) wrote : Re: [Bug 1875548] Re: Its not easy to determine how to skip the filesystem check

Jay:
A line comes up about disk check but no disk check is performed. If you
remove the line "fsck.mode=skip" from grub you should see the difference,
the check shows every file.

On Fri, Feb 5, 2021 at 11:21 AM Jay Michael <email address hidden>
wrote:

> Ubuntu 20.04.2 behaves the same way.
>
> "quiet" kernel parameter seems to enable skipping the disk check: With
> "quiet" on the kernel command line, one of the few lines to appear on
> the screen is "disk check skipped", and the boot completes noticeably
> faster. (35s instead of 55s, booting from an ISO file on a hard disk)
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1875548
>
> Title:
> Its not easy to determine how to skip the filesystem check
>
> Status in casper package in Ubuntu:
> Fix Released
>
> Bug description:
> I see that Live Ubuntu 20.04 is plagued by disk checking on boot.
>
> Not just with Live USB but with Persistent USB also.
>
> If not fast enough to cancel with ctl-c it starts on
> filesystem.squashfs and runs until over 90% complete.
>
> Very irritating. There have been quite a few complaints on Ask Ubuntu
> already.
>
> If it was just a run once it would not be so bad.
>
> Is there some way to get rid of this or is it a bug we have to live
> with?
>
> Perusing Ask Ubuntu everyday for many years I have never seen anybody
> ask for such a feature.
>
> A run once filesystem check might have its uses on a Live installer
> drive but is not needed on a Persistent utility drive.
>
> The only alternative I see is to use a Full install USB drive were
> automatic disk checking is not run.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 20.04
> Package: ubuntu-release-upgrader-core 1:20.04.18
> ProcVersionSignature: Ubuntu 5.4.0-26.30-generic 5.4.30
> Uname: Linux 5.4.0-26-generic x86_64
> NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
> ApportVersion: 2.20.11-0ubuntu27
> Architecture: amd64
> CasperMD5CheckResult: skip
> CasperVersion: 1.445
> CrashDB: ubuntu
> CurrentDesktop: ubuntu:GNOME
> Date: Tue Apr 28 06:07:32 2020
> LiveMediaBuild: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
> PackageArchitecture: all
> ProcEnviron:
> TERM=xterm-256color
> PATH=(custom, no user)
> XDG_RUNTIME_DIR=<set>
> LANG=C.UTF-8
> SHELL=/bin/bash
> SourcePackage: ubuntu-release-upgrader
> Symptom: dist-upgrade
> UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1875548/+subscriptions
>

Revision history for this message
Jay Michael (jmichael-ll) wrote :

     "fsck.mode=skip" does *not* skip disk check unless "quiet" is also on the kernel command line.

     Without "quiet" on the kernel command line, even with "fsck.mode=skip", I see lines flying by until it gets to the squashfs file, at which point it pauses long enough for me to read some lines.

Revision history for this message
C.S.Cameron (cscameron) wrote :

Jay:
What are you using to make your USB, ISO boot using GRUB2, or a tool like
Rufus or mkusb?
I can not duplicate your result using Rufus with Syslinux boot in BIOS mode.
I will try ISO boot using GRUB2 next.

On Sat, Feb 6, 2021 at 10:30 AM Jay Michael <email address hidden>
wrote:

> "fsck.mode=skip" does *not* skip disk check unless "quiet" is also
> on the kernel command line.
>
> Without "quiet" on the kernel command line, even with
> "fsck.mode=skip", I see lines flying by until it gets to the squashfs
> file, at which point it pauses long enough for me to read some lines.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1875548
>
> Title:
> Its not easy to determine how to skip the filesystem check
>
> Status in casper package in Ubuntu:
> Fix Released
>
> Bug description:
> I see that Live Ubuntu 20.04 is plagued by disk checking on boot.
>
> Not just with Live USB but with Persistent USB also.
>
> If not fast enough to cancel with ctl-c it starts on
> filesystem.squashfs and runs until over 90% complete.
>
> Very irritating. There have been quite a few complaints on Ask Ubuntu
> already.
>
> If it was just a run once it would not be so bad.
>
> Is there some way to get rid of this or is it a bug we have to live
> with?
>
> Perusing Ask Ubuntu everyday for many years I have never seen anybody
> ask for such a feature.
>
> A run once filesystem check might have its uses on a Live installer
> drive but is not needed on a Persistent utility drive.
>
> The only alternative I see is to use a Full install USB drive were
> automatic disk checking is not run.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 20.04
> Package: ubuntu-release-upgrader-core 1:20.04.18
> ProcVersionSignature: Ubuntu 5.4.0-26.30-generic 5.4.30
> Uname: Linux 5.4.0-26-generic x86_64
> NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
> ApportVersion: 2.20.11-0ubuntu27
> Architecture: amd64
> CasperMD5CheckResult: skip
> CasperVersion: 1.445
> CrashDB: ubuntu
> CurrentDesktop: ubuntu:GNOME
> Date: Tue Apr 28 06:07:32 2020
> LiveMediaBuild: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
> PackageArchitecture: all
> ProcEnviron:
> TERM=xterm-256color
> PATH=(custom, no user)
> XDG_RUNTIME_DIR=<set>
> LANG=C.UTF-8
> SHELL=/bin/bash
> SourcePackage: ubuntu-release-upgrader
> Symptom: dist-upgrade
> UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1875548/+subscriptions
>

Revision history for this message
Jay Michael (jmichael-ll) wrote :

     I craft my boot device by hand. I'm using files filched from some Ubuntu distribution (so, GRUB2), lately booting with the ISO file. I've booted from an external (USB) hard disk, and from thumb drives.

     On my external hard drive, I copied vmlinuz and initrd to the ESP (because on another machine, with Secure Boot enabled, the version of GRUB2 I filched does not support NTFS filesystems, and I cannot insert the appropriate module). The ISO file is in a subdirectory of an NTFS partition. The GRUB2 item is:

set bdir=(${root})/boot
set fsd=/os/boot
menuentry "Ubuntu 20.04.2 64-bit via ISO" {
  set gfxpayload=keep
  set ubdir=${bdir}/ubuntu200402-64
  set isopath=${fsd}/ubuntu-20.04.2-desktop-amd64.iso
  linux ${ubdir}/vmlinuz boot=casper iso-scan/filename=${isopath} ignore_uuid fsck.mode=skip
  initrd ${ubdir}/initrd
}

     So, GRUB is told to load the kernel and initrd from the FAT-formatted ESP, while the kernel is told to find the ISO file.

     I observed the same behavior with 20.04.1 as with 20.04.2.
     I observed the same behavior when booting from a thumb drive as when booting from a hard drive.

     I haven't tried to find a copy of "20.04". Was there such a thing? Or was 20.04.1 the first released version, the one referred to in all those posts complaining about the automatic disk check?

Revision history for this message
Jay Michael (jmichael-ll) wrote :

     Forget "quiet", it's whether "fsck.mode=skip" is the last thing on the kernel command line.

     There is no disk check if there is something after "fsck.mode=skip". I tried "quiet". Then I tried "nomodeset" instead.

     I tried putting a blank at the end of the line. That was *not* enough to make the "fsck" stop the disk check. I was using the GRUB2 editor, so maybe it would have worked if I really added a blank at the end of the line in the grub.cfg file.

     Also, Ctrl-C does *not* abort the disk check. Given the way the display crawled through a flock of files before saying it was on squashfs, I'm pretty sure I hit the Ctrl-C before it had started on squashfs -- It just did not pay attention.

Revision history for this message
Mauricio Faria de Oliveira (mfo) wrote :

The first issue in comment #18 (fsck.mode=skip is ignored if it's
last on cmdline) is in progress in bug 1892369 (comment 34) [1].

The second issue (ctrl-c doesn't abort the disk check) is also
described there, and unfortunately it's a limitation which was
introduced as part of another change, apparently (not a bug),
and is no longer an option.

...

Currently, to skip the disk integrity check (casper-md5check),
please insert 'fsck.mode=skip' before '---' in kernel cmdline
(i.e., make sure it's not the last string).

[1] https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1892369/comments/34

Revision history for this message
C.S.Cameron (cscameron) wrote :

I do not think I have had a Live USB to do a disk check with 20.10 and
later, except with 22.04 daily.

On Tue, Mar 22, 2022 at 11:36 AM Mauricio Faria de Oliveira <
<email address hidden>> wrote:

> The first issue in comment #18 (fsck.mode=skip is ignored if it's
> last on cmdline) is in progress in bug 1892369 (comment 34) [1].
>
> The second issue (ctrl-c doesn't abort the disk check) is also
> described there, and unfortunately it's a limitation which was
> introduced as part of another change, apparently (not a bug),
> and is no longer an option.
>
> ...
>
> Currently, to skip the disk integrity check (casper-md5check),
> please insert 'fsck.mode=skip' before '---' in kernel cmdline
> (i.e., make sure it's not the last string).
>
> [1]
> https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1892369/comments/34
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1875548
>
> Title:
> Its not easy to determine how to skip the filesystem check
>
> Status in casper package in Ubuntu:
> Fix Released
>
> Bug description:
> I see that Live Ubuntu 20.04 is plagued by disk checking on boot.
>
> Not just with Live USB but with Persistent USB also.
>
> If not fast enough to cancel with ctl-c it starts on
> filesystem.squashfs and runs until over 90% complete.
>
> Very irritating. There have been quite a few complaints on Ask Ubuntu
> already.
>
> If it was just a run once it would not be so bad.
>
> Is there some way to get rid of this or is it a bug we have to live
> with?
>
> Perusing Ask Ubuntu everyday for many years I have never seen anybody
> ask for such a feature.
>
> A run once filesystem check might have its uses on a Live installer
> drive but is not needed on a Persistent utility drive.
>
> The only alternative I see is to use a Full install USB drive were
> automatic disk checking is not run.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 20.04
> Package: ubuntu-release-upgrader-core 1:20.04.18
> ProcVersionSignature: Ubuntu 5.4.0-26.30-generic 5.4.30
> Uname: Linux 5.4.0-26-generic x86_64
> NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
> ApportVersion: 2.20.11-0ubuntu27
> Architecture: amd64
> CasperMD5CheckResult: skip
> CasperVersion: 1.445
> CrashDB: ubuntu
> CurrentDesktop: ubuntu:GNOME
> Date: Tue Apr 28 06:07:32 2020
> LiveMediaBuild: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
> PackageArchitecture: all
> ProcEnviron:
> TERM=xterm-256color
> PATH=(custom, no user)
> XDG_RUNTIME_DIR=<set>
> LANG=C.UTF-8
> SHELL=/bin/bash
> SourcePackage: ubuntu-release-upgrader
> Symptom: dist-upgrade
> UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1875548/+subscriptions
>
>

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