On Mon, 2021-03-29 at 18:40 -0700, Lou Poppler wrote:
> On Mon, 2021-03-29 at 20:16 +0200, J.A. Bezemer wrote:
> >
> > The problem seems to be that no loop module is available, so the squashfs
> > can't be loop-mounted from the file on the installer medium. Did the
> > loop-modules-4.19.0-16-686-di package get lost somewhere?
>
> Update: Steve McIntyre spent some time on IRC helping to debug this.
> The problem is "Low Memory" mode getting too aggressive kicking out components
> from the RAM FS, including that loop module. We found a low-mem menu that is
> supposed to load and keep that module (and others) but it doesn't seem to be
> working correctly right now. I even anna-install'ed the module again from the
> network on one attempt, but the installer couldn't find it anymore.
>
> Just to be clear, we are talking here about trying to use the text-mode
> installer from the boot menu of a buster debian-live ISO image.
> I'm trying to take a look at the lowmem code now.
>
loop.ko is in /lib/modules/4.19.0-16-686/kernel/drivers/block/
which is deleted by the following aggressive code in
lowmem-1.47/partman/init.d/05lowmem_modules
-------------------------------------------------------------
#!/bin/sh
set -e
if [ ! -e /var/lib/lowmem ]; then
exit 0
fi
# Let's not delete anything yet if no discs have been found
if [ "$(list-devices disk)" ]; then
if cd /lib/modules/*/kernel/drivers; then
rm -rf net cdrom ide ieee1394 input scsi usb video
parport block
fi
fi
--------------------------------------------------------------
I defeated this by removing /var/lib/lowmem at VC2 before partman, and this
allowed the installer to find the loop.ko module. However it failed soon after:
Mar 30 14:17:22 kernel: [ 1004.240890] Adding 979960k swap on /dev/sda3.
Priority:-3 extents:1 across:979960k FS
Mar 30 14:17:23 kernel: [ 1005.647027] EXT4-fs (sda8): mounted filesystem with
ordered data mode. Opts: errors=remount-ro
Mar 30 14:17:23 kernel: [ 1005.700346] EXT4-fs (sda1): mounting ext3 file
system using the ext4 subsystem
Mar 30 14:17:23 kernel: [ 1005.871947] EXT4-fs (sda1): mounted filesystem with
ordered data mode. Opts: (null)
Mar 30 14:17:25 apt-install: Queueing package e2fsprogs for later installation
Mar 30 14:17:26 main-menu[227]: INFO: Falling back to the package description
for brltty-udeb
Mar 30 14:17:26 main-menu[227]: INFO: Falling back to the package description
for brltty-udeb
Mar 30 14:17:26 main-menu[227]: INFO: Menu item 'live-installer' selected
Mar 30 14:17:28 base-installer: info: Using squashfs support for
/cdrom/live/filesystem.squashfs
Mar 30 14:17:28 anna-install: Installing squashfs-modules
Mar 30 14:17:28 anna[8759]: ERROR **: can't find packages file
Mar 30 14:17:29 kernel: [ 1011.708557] loop: module loaded
Mar 30 14:17:29 base-installer: error: /cdrom/live/filesystem.squashfs has
failed to be mounted as squashfs.
Mar 30 14:17:29 main-menu[227]: (process:8706): modprobe: FATAL: Module
squashfs not found in directory /lib/modules/4.19.0-16-686
Mar 30 14:17:29 main-menu[227]: (process:8706): mount: mounting /dev/loop0 on
/mnt failed: No such device
------
I need to investigate more with this. At the failure point above, free RAM is
212100 KB. What I am leaning toward suggesting is to modify the code in
lowmem-1.47/debian-installer-startup.d/S15lowmem
to allow the user to set lowmem=0 on the installer command line
(and add more detail to the install manual documentation of lowmem).
