The device is OnePlus 8 Pro, it is completely functional, booted for root ADB from LineageOS Recovery via
fastboot -s XXXXXXXX boot lineage-recovery.img.$ adb --version Android Debug Bridge version 1.0.41 Version 31.0.2-7242960 Installed as /opt/android-sdk/platform-tools/adb
Trying to follow some 4-6 years old online guides & QnAs (mostly written by Irfan Latif) on how to backup stock ROM & partitions using adb pull or adb exec-out.
All of these materials always reference an mmcblk0 partition. But in my case it is missing.
What I have instead are these:
$ adb -s XXXXXXXX shell 'ls -al /dev/block' | grep -e '^[^d]'
total 0
lrwxrwxrwx 1 root root 37 1970-04-15 15:06 bootdevice -> /dev/block/platform/soc/XXXXXXX.ufshc
brw------- 1 root root 7, 0 1970-04-15 15:06 loop0
brw------- 1 root root 7, 8 1970-04-15 15:06 loop1
brw------- 1 root root 7, 80 1970-04-15 15:06 loop10
brw------- 1 root root 7, 88 1970-04-15 15:06 loop11
brw------- 1 root root 7, 96 1970-04-15 15:06 loop12
brw------- 1 root root 7, 104 1970-04-15 15:06 loop13
brw------- 1 root root 7, 112 1970-04-15 15:06 loop14
brw------- 1 root root 7, 120 1970-04-15 15:06 loop15
brw------- 1 root root 7, 16 1970-04-15 15:06 loop2
brw------- 1 root root 7, 24 1970-04-15 15:06 loop3
brw------- 1 root root 7, 32 1970-04-15 15:06 loop4
brw------- 1 root root 7, 40 1970-04-15 15:06 loop5
brw------- 1 root root 7, 48 1970-04-15 15:06 loop6
brw------- 1 root root 7, 56 1970-04-15 15:06 loop7
brw------- 1 root root 7, 64 1970-04-15 15:06 loop8
brw------- 1 root root 7, 72 1970-04-15 15:06 loop9
brw------- 1 root root 1, 0 1970-04-15 15:06 ram0
brw------- 1 root root 1, 1 1970-04-15 15:06 ram1
brw------- 1 root root 1, 10 1970-04-15 15:06 ram10
brw------- 1 root root 1, 11 1970-04-15 15:06 ram11
brw------- 1 root root 1, 12 1970-04-15 15:06 ram12
brw------- 1 root root 1, 13 1970-04-15 15:06 ram13
brw------- 1 root root 1, 14 1970-04-15 15:06 ram14
brw------- 1 root root 1, 15 1970-04-15 15:06 ram15
brw------- 1 root root 1, 2 1970-04-15 15:06 ram2
brw------- 1 root root 1, 3 1970-04-15 15:06 ram3
brw------- 1 root root 1, 4 1970-04-15 15:06 ram4
brw------- 1 root root 1, 5 1970-04-15 15:06 ram5
brw------- 1 root root 1, 6 1970-04-15 15:06 ram6
brw------- 1 root root 1, 7 1970-04-15 15:06 ram7
brw------- 1 root root 1, 8 1970-04-15 15:06 ram8
brw------- 1 root root 1, 9 1970-04-15 15:06 ram9
brw------- 1 root root 8, 0 1970-04-15 15:06 sda
brw------- 1 root root 8, 1 1970-04-15 15:06 sda1
brw------- 1 root root 8, 10 1970-04-15 15:06 sda10
brw------- 1 root root 8, 11 1970-04-15 15:06 sda11
brw------- 1 root root 8, 12 1970-04-15 15:06 sda12
brw------- 1 root root 8, 13 1970-04-15 15:06 sda13
brw------- 1 root root 8, 14 1970-04-15 15:06 sda14
brw------- 1 root root 8, 15 1970-04-15 15:06 sda15
brw------- 1 root root 259, 0 1970-04-15 15:06 sda16
brw------- 1 root root 259, 1 1970-04-15 15:06 sda17
brw------- 1 root root 259, 2 1970-04-15 15:06 sda18
brw------- 1 root root 259, 3 1970-04-15 15:06 sda19
brw------- 1 root root 8, 2 1970-04-15 15:06 sda2
brw------- 1 root root 259, 4 1970-04-15 15:06 sda20
brw------- 1 root root 259, 5 1970-04-15 15:06 sda21
brw------- 1 root root 259, 6 1970-04-15 15:06 sda22
brw------- 1 root root 259, 7 1970-04-15 15:06 sda23
brw------- 1 root root 8, 3 1970-04-15 15:09 sda3
brw------- 1 root root 8, 4 1970-04-15 15:06 sda4
brw------- 1 root root 8, 5 1970-04-15 15:06 sda5
brw------- 1 root root 8, 6 1970-04-15 15:06 sda6
brw------- 1 root root 8, 7 1970-04-15 15:06 sda7
brw------- 1 root root 8, 8 1970-04-15 15:06 sda8
brw------- 1 root root 8, 9 1970-04-15 15:06 sda9
brw------- 1 root root 8, 16 1970-04-15 15:06 sdb
brw------- 1 root root 8, 17 1970-04-15 15:06 sdb1
brw------- 1 root root 8, 18 1970-04-15 15:06 sdb2
brw------- 1 root root 8, 32 1970-04-15 15:06 sdc
brw------- 1 root root 8, 33 1970-04-15 15:06 sdc1
brw------- 1 root root 8, 34 1970-04-15 15:06 sdc2
brw------- 1 root root 8, 48 1970-04-15 15:06 sdd
brw------- 1 root root 8, 49 1970-04-15 15:06 sdd1
brw------- 1 root root 8, 50 1970-04-15 15:06 sdd2
brw------- 1 root root 8, 51 1970-04-15 15:06 sdd3
brw------- 1 root root 8, 52 1970-04-15 15:06 sdd4
brw------- 1 root root 8, 64 1970-04-15 15:06 sde
brw------- 1 root root 8, 65 1970-04-15 15:06 sde1
brw------- 1 root root 8, 74 1970-04-15 15:06 sde10
brw------- 1 root root 8, 75 1970-04-15 15:06 sde11
brw------- 1 root root 8, 76 1970-04-15 15:06 sde12
brw------- 1 root root 8, 77 1970-04-15 15:06 sde13
brw------- 1 root root 8, 78 1970-04-15 15:06 sde14
brw------- 1 root root 8, 79 1970-04-15 15:06 sde15
brw------- 1 root root 259, 8 1970-04-15 15:06 sde16
brw------- 1 root root 259, 9 1970-04-15 15:06 sde17
brw------- 1 root root 259, 10 1970-04-15 15:06 sde18
brw------- 1 root root 259, 11 1970-04-15 15:06 sde19
brw------- 1 root root 8, 66 1970-04-15 15:06 sde2
brw------- 1 root root 259, 12 1970-04-15 15:06 sde20
brw------- 1 root root 259, 13 1970-04-15 15:06 sde21
brw------- 1 root root 259, 14 1970-04-15 15:06 sde22
brw------- 1 root root 259, 15 1970-04-15 15:06 sde23
brw------- 1 root root 259, 16 1970-04-15 15:06 sde24
brw------- 1 root root 259, 17 1970-04-15 15:06 sde25
brw------- 1 root root 259, 18 1970-04-15 15:06 sde26
brw------- 1 root root 259, 19 1970-04-15 15:06 sde27
brw------- 1 root root 259, 20 1970-04-15 15:06 sde28
brw------- 1 root root 259, 21 1970-04-15 15:06 sde29
brw------- 1 root root 8, 67 1970-04-15 15:06 sde3
brw------- 1 root root 259, 22 1970-04-15 15:06 sde30
brw------- 1 root root 259, 23 1970-04-15 15:06 sde31
brw------- 1 root root 259, 24 1970-04-15 15:06 sde32
brw------- 1 root root 259, 25 1970-04-15 15:06 sde33
brw------- 1 root root 259, 26 1970-04-15 15:06 sde34
brw------- 1 root root 259, 27 1970-04-15 15:06 sde35
brw------- 1 root root 259, 28 1970-04-15 15:06 sde36
brw------- 1 root root 259, 29 1970-04-15 15:06 sde37
brw------- 1 root root 259, 30 1970-04-15 15:06 sde38
brw------- 1 root root 259, 31 1970-04-15 15:06 sde39
brw------- 1 root root 8, 68 1970-04-15 15:06 sde4
brw------- 1 root root 259, 32 1970-04-15 15:06 sde40
brw------- 1 root root 259, 33 1970-04-15 15:06 sde41
brw------- 1 root root 259, 34 1970-04-15 15:06 sde42
brw------- 1 root root 259, 35 1970-04-15 15:06 sde43
brw------- 1 root root 259, 36 1970-04-15 15:06 sde44
brw------- 1 root root 259, 37 1970-04-15 15:06 sde45
brw------- 1 root root 259, 38 1970-04-15 15:06 sde46
brw------- 1 root root 259, 39 1970-04-15 15:06 sde47
brw------- 1 root root 259, 40 1970-04-15 15:06 sde48
brw------- 1 root root 259, 41 1970-04-15 15:06 sde49
brw------- 1 root root 8, 69 1970-04-15 15:06 sde5
brw------- 1 root root 259, 42 1970-04-15 15:06 sde50
brw------- 1 root root 259, 43 1970-04-15 15:06 sde51
brw------- 1 root root 259, 44 1970-04-15 15:06 sde52
brw------- 1 root root 259, 45 1970-04-15 15:06 sde53
brw------- 1 root root 259, 46 1970-04-15 15:06 sde54
brw------- 1 root root 259, 47 1970-04-15 15:06 sde55
brw------- 1 root root 259, 48 1970-04-15 15:06 sde56
brw------- 1 root root 259, 49 1970-04-15 15:06 sde57
brw------- 1 root root 259, 50 1970-04-15 15:06 sde58
brw------- 1 root root 259, 51 1970-04-15 15:06 sde59
brw------- 1 root root 8, 70 1970-04-15 15:06 sde6
brw------- 1 root root 259, 52 1970-04-15 15:06 sde60
brw------- 1 root root 259, 53 1970-04-15 15:06 sde61
brw------- 1 root root 259, 54 1970-04-15 15:06 sde62
brw------- 1 root root 259, 55 1970-04-15 15:06 sde63
brw------- 1 root root 259, 56 1970-04-15 15:06 sde64
brw------- 1 root root 259, 57 1970-04-15 15:06 sde65
brw------- 1 root root 259, 58 1970-04-15 15:06 sde66
brw------- 1 root root 259, 59 1970-04-15 15:06 sde67
brw------- 1 root root 259, 60 1970-04-15 15:06 sde68
brw------- 1 root root 259, 61 1970-04-15 15:06 sde69
brw------- 1 root root 8, 71 1970-04-15 15:06 sde7
brw------- 1 root root 259, 62 1970-04-15 15:06 sde70
brw------- 1 root root 259, 63 1970-04-15 15:06 sde71
brw------- 1 root root 259, 64 1970-04-15 15:06 sde72
brw------- 1 root root 259, 65 1970-04-15 15:06 sde73
brw------- 1 root root 259, 66 1970-04-15 15:06 sde74
brw------- 1 root root 259, 67 1970-04-15 15:06 sde75
brw------- 1 root root 259, 68 1970-04-15 15:06 sde76
brw------- 1 root root 8, 72 1970-04-15 15:06 sde8
brw------- 1 root root 8, 73 1970-04-15 15:06 sde9
brw------- 1 root root 8, 80 1970-04-15 15:06 sdf
brw------- 1 root root 8, 81 1970-04-15 15:06 sdf1
brw------- 1 root root 8, 82 1970-04-15 15:06 sdf2
brw------- 1 root root 8, 83 1970-04-15 15:06 sdf3
brw------- 1 root root 8, 84 1970-04-15 15:06 sdf4
brw------- 1 root root 8, 85 1970-04-15 15:06 sdf5
brw------- 1 root root 8, 86 1970-04-15 15:06 sdf6
brw------- 1 root root 8, 87 1970-04-15 15:06 sdf7
brw------- 1 root root 8, 88 1970-04-15 15:06 sdf8
brw------- 1 root root 8, 89 1970-04-15 15:06 sdf9
brw------- 1 root root 254, 0 1970-04-15 15:06 zram0
by-name:
$ adb -s XXXXXXXX shell 'ls -alpsh /dev/block/by-name'
total 0
0 drwxr-xr-x 2 root root 2.4K 1970-04-15 15:06 ./
0 drwxr-xr-x 5 root root 3.1K 1970-04-15 15:06 ../
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 ALIGN_TO_128K_1 -> /dev/block/sdd1
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 ALIGN_TO_128K_2 -> /dev/block/sdf1
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 abl_a -> /dev/block/sde8
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 abl_b -> /dev/block/sde32
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 abl_log -> /dev/block/sde67
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 aging_kernel -> /dev/block/sde64
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 aging_mod -> /dev/block/sde65
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 android_log -> /dev/block/sde69
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 aop_a -> /dev/block/sde1
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 aop_b -> /dev/block/sde25
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 apdp -> /dev/block/sde51
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 bluetooth_a -> /dev/block/sde5
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 bluetooth_b -> /dev/block/sde29
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 boot_a -> /dev/block/sde11
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 boot_b -> /dev/block/sde35
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 cdt -> /dev/block/sdd2
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 cmnlib64_a -> /dev/block/sde13
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 cmnlib64_b -> /dev/block/sde37
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 cmnlib_a -> /dev/block/sde12
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 cmnlib_b -> /dev/block/sde36
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 config -> /dev/block/sda11
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 ddr -> /dev/block/sdd3
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 devcfg_a -> /dev/block/sde14
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 devcfg_b -> /dev/block/sde38
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 devinfo -> /dev/block/sde49
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 dip -> /dev/block/sde50
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 dsp_a -> /dev/block/sde9
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 dsp_b -> /dev/block/sde33
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 dtbo_a -> /dev/block/sde17
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 dtbo_b -> /dev/block/sde41
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 featenabler_a -> /dev/block/sde22
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 featenabler_b -> /dev/block/sde46
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 frp -> /dev/block/sda5
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 fsc -> /dev/block/sdf5
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 fsg -> /dev/block/sdf4
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 hyp_a -> /dev/block/sde3
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 hyp_b -> /dev/block/sde27
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 hyp_log -> /dev/block/sde71
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 imagefv_a -> /dev/block/sde23
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 imagefv_b -> /dev/block/sde47
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 kernel_log -> /dev/block/sde68
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 keymaster_a -> /dev/block/sde10
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 keymaster_b -> /dev/block/sde34
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 keystore -> /dev/block/sda4
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 limits -> /dev/block/sde54
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 limits-cdsp -> /dev/block/sde55
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 logdump -> /dev/block/sde57
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 logfs -> /dev/block/sde56
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 logo_a -> /dev/block/sde24
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 logo_b -> /dev/block/sde48
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdm1m9kefs1 -> /dev/block/sdf7
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdm1m9kefs2 -> /dev/block/sdf8
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdm1m9kefs3 -> /dev/block/sdf6
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdm1m9kefsc -> /dev/block/sdf9
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 mdm1oemnvbktmp -> /dev/block/sde63
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdm_oem_dycnvbk -> /dev/block/sda7
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdm_oem_stanvbk -> /dev/block/sda8
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdmddr -> /dev/block/sdd4
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdtp_a -> /dev/block/sde7
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 mdtp_b -> /dev/block/sde31
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 mdtpsecapp_a -> /dev/block/sde6
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 mdtpsecapp_b -> /dev/block/sde30
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 metadata -> /dev/block/sda19
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 misc -> /dev/block/sda3
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 modem_a -> /dev/block/sde4
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 modem_b -> /dev/block/sde28
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 modemdump -> /dev/block/sda9
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 modemst1 -> /dev/block/sdf2
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 modemst2 -> /dev/block/sdf3
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 msadp -> /dev/block/sde52
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 multiimgoem_a -> /dev/block/sde19
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 multiimgoem_b -> /dev/block/sde43
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 multiimgqti_a -> /dev/block/sde20
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 multiimgqti_b -> /dev/block/sde44
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 op1 -> /dev/block/sde66
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 op2 -> /dev/block/sda10
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 opproduct_a -> /dev/block/sda12
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 opproduct_b -> /dev/block/sda13
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 param -> /dev/block/sda6
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 persist -> /dev/block/sda2
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 qsee_log -> /dev/block/sde70
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 qupfw_a -> /dev/block/sde15
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 qupfw_b -> /dev/block/sde39
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 rawdump -> /dev/block/sda22
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 recovery_a -> /dev/block/sda15
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 recovery_b -> /dev/block/sda16
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 reserve1 -> /dev/block/sde72
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 reserve2 -> /dev/block/sde73
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 reserve3 -> /dev/block/sde74
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 reserve4 -> /dev/block/sde75
0 lrwxrwxrwx 1 root root 14 1970-04-15 15:06 sda -> /dev/block/sda
0 lrwxrwxrwx 1 root root 14 1970-04-15 15:06 sdb -> /dev/block/sdb
0 lrwxrwxrwx 1 root root 14 1970-04-15 15:06 sdc -> /dev/block/sdc
0 lrwxrwxrwx 1 root root 14 1970-04-15 15:06 sdd -> /dev/block/sdd
0 lrwxrwxrwx 1 root root 14 1970-04-15 15:06 sde -> /dev/block/sde
0 lrwxrwxrwx 1 root root 14 1970-04-15 15:06 sdf -> /dev/block/sdf
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 secdata -> /dev/block/sde60
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 spunvm -> /dev/block/sde53
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 ssd -> /dev/block/sda1
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 storsec_a -> /dev/block/sde58
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 storsec_b -> /dev/block/sde76
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 super -> /dev/block/sda14
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 tz_a -> /dev/block/sde2
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 tz_b -> /dev/block/sde26
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 uefisecapp_a -> /dev/block/sde18
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 uefisecapp_b -> /dev/block/sde42
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 uefivarstore -> /dev/block/sde59
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 userdata -> /dev/block/sda23
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vbmeta_a -> /dev/block/sde16
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vbmeta_b -> /dev/block/sde40
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vbmeta_system_a -> /dev/block/sda17
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vbmeta_system_b -> /dev/block/sda18
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vm-data -> /dev/block/sde62
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vm-keystore -> /dev/block/sde61
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vm-linux_a -> /dev/block/sde21
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vm-linux_b -> /dev/block/sde45
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vm-system_a -> /dev/block/sda20
0 lrwxrwxrwx 1 root root 16 1970-04-15 15:06 vm-system_b -> /dev/block/sda21
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 xbl_a -> /dev/block/sdb1
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 xbl_b -> /dev/block/sdc1
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 xbl_config_a -> /dev/block/sdb2
0 lrwxrwxrwx 1 root root 15 1970-04-15 15:06 xbl_config_b -> /dev/block/sdc2
The command below produces an empty 71 byte archive.
$ adb -s XXXXXXXX exec-out 'cat /dev/block/mmcblk0 | gzip' > backup/partitions/mmcblk0.tar.gz
$ ls -shlap backup/partitions/mmcblk0.tar.gz
4.0K -rw-rw-r-- 1 tanhok tanhok 71 Aug 5 18:26 backup/partitions/mmcblk0.tar.gz
Which one of those is "the new mmcblk0"? Which one should I pull to have a full backup of my device stock firmware as an .img file?
mmcblkis the naming convention for eMMC flash storage block devices.sd[X]is the convention for the new UFS chips, like HDDs and SSDs.mmcblk0is not a partition, but the whole flash storage block device.sd[a|b|c|d|e|f]block devices. But if you don't know why to or how to or what to backup, the backup won't be of any use to you, in most cases.