[Android Q&A, Help & Troubleshooting] bidibidi:
Hi,

Completely new to smartphones in general, I just bought a second-hand Samsung Galaxy S2 from a specialized website. I tried to install LineageOS on it but with no success so far (the LineageOS wiki for this device seems to forget some important things when starting from a stock ROM).

Current situation and things that might help:

I don't have a microSD card.

I have a backup of the original .pit file.

Even if I really do not want to use the stock ROM, I can not find a way to reinstall a working one: installation with Odin works but there is a "boot loop" on the Samsung logo.

Installing Replicant works, but it is unfortunately too extremist for me.

As I don't have a microSD card, I try installing with "adb sideload image_file.zip" (like I do with Replicant), but TWRP displays errors about partitions :

...
E:Unable to locate storage partition for storing settings file.
Updating partition details...
...done
Unable to find partition for path '/system'
Unable to find partition for path '/data'
MTP enabled
Starting ADB sideload feature...
Installing zip file '/sideload/package.zip'
Target: samsung/GT-I9100:4.1.2/JZ054K/I9100XWMS2:user/release-keys
detected filesystem ext4 for /dev/blockmmcblk0p9
detected filesystem ext4 for /dev/blockmmcblk0p10
Can't install this package on top of incompatible data.
Please try another package or run a factory reset
Updater process ended with ERROR: 7

I tried doing a "factory reset" from TWRP but result is the same.

Here are some information that might be useful, gathered from an ADB shell:

/etc/recovery.fstab

# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK
# data partition must be located at the bottom for supporting device encryption

/dev/block/mmcblk0p9 /system ext4 ro,noatime wait
/dev/block/mmcblk0p7 /cache ext4 noatime,nosuid,nodev,journal_async_commit,errors=panic wait,check_spo
/dev/block/mmcblk0p1 /efs ext4 noatime,nosuid,nodev,journal_async_commit,errors=panic wait,check_spo
/dev/block/mmcblk0p10 /data ext4 noatime,nosuid,nodev,noauto_da_alloc,journal_async_commit,errors=panic wait,check_spo,encryptable=/efs/metadata
/dev/block/mmcblk0p12 /preload ext4 noatime,nosuid,nodev,journal_async_commit wait

# vold-managed volumes ("block device" is actually a sysfs devpath)
/devices/platform/dw_mmc/mmc_host/mmc0/mmc0* auto auto defaults wait,voldmanaged=sdcard0:11,nonremovable,noemulatedsd
/devices/platform/s3c-sdhci.2/mmc_host/mmc1* auto auto defaults wait,voldmanaged=sdcard1:auto,noemulatedsd
/devices/platform/s3c_otghcd/usb* auto auto defaults voldmanaged=usbdisk0:auto

# recovery
/dev/block/mmcblk0p5 /boot emmc defaults recoveryonly
/dev/block/mmcblk0p6 /recovery emmc defaults recoveryonly

/etc/mtab

rootfs / rootfs rw,seclabel 0 0
tmpfs /dev tmpfs rw,seclabel,nosuid,relatime,mode=755 0 0
devpts /dev/pts devpts rw,seclabel,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,seclabel,relatime 0 0
selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0
tmpfs /tmp tmpfs rw,seclabel,relatime 0 0

/tmp/recovery.fstab

...
=> Linking mtab
=> Processing recovery.fstab
I:Processing '/dev/block/mmcblk0p9'
E:Invalid block device 'ext4' in fstab line '/dev/block/mmcblk0p9 /system ext4 ro,noatime
wait
'I:Processing '/dev/block/mmcblk0p7'
E:Invalid block device 'ext4' in fstab line '/dev/block/mmcblk0p7 /cache ext4 noatime,nosuid,nodev,journal_async_commit,errors=panic wait,check_spo
'I:Processing '/dev/block/mmcblk0p1'
E:Invalid block device 'ext4' in fstab line '/dev/block/mmcblk0p1 /efs ext4 noatime,nosuid,nodev,journal_async_commit,errors=panic wait,check_spo
'I:Processing '/dev/block/mmcblk0p10'
E:Invalid block device 'ext4' in fstab line '/dev/block/mmcblk0p10 /data ext4 noatime,nosuid,nodev,noauto_da_alloc,journal_async_commit,errors=panic wait,check_spo,encryptable=/efs/metadata
'I:Processing '/dev/block/mmcblk0p12'
E:Invalid block device 'ext4' in fstab line '/dev/block/mmcblk0p12 /preload ext4 noatime,nosuid,nodev,journal_async_commit wait
'I:Processing '/devices/platform/dw_mmc/mmc_host/mmc0/mmc0*'
E:Invalid block device 'auto' in fstab line '/devices/platform/dw_mmc/mmc_host/mmc0/mmc0* auto auto defaults wait,voldmanaged=sdcard0:11,nonremovable,noemulatedsd
'I:Processing '/devices/platform/s3c-sdhci.2/mmc_host/mmc1*'
E:Invalid block device 'auto' in fstab line '/devices/platform/s3c-sdhci.2/mmc_host/mmc1* auto auto defaults wait,voldmanaged=sdcard1:auto,noemulatedsd
'I:Processing '/devices/platform/s3c_otghcd/usb*'
E:Invalid block device 'auto' in fstab line '/devices/platform/s3c_otghcd/usb* auto auto defaults voldmanaged=usbdisk0:auto
'I:Processing '/dev/block/mmcblk0p5'
E:Invalid block device 'emmc' in fstab line '/dev/block/mmcblk0p5 /boot emmc defaults recoveryonly
'I:Processing '/dev/block/mmcblk0p6'
E:Invalid block device 'emmc' in fstab line '/dev/block/mmcblk0p6 /recovery emmc defaults recoveryonly
'E:Unable to locate storage partition for storing settings file.
Updating partition details...
...done
I:Unable to find storage partition '/'.
I:Unmounting main partitions...
Unable to find partition for path '/system'
Unable to find partition for path '/data'
...

I spent many hours hours on this issue and read many many things. I really hope someone will be able to help, or at least sympathise :) Feel free to ask if I can provide some information. Thanks!