[Google Pixel Guides, News, & Discussion] aljomaz:
I thought it might be helpful to others to document some test results after rooting my Google Pixel (2016) phone with Magisk (v20.4) and Magisk Manager (v8.0.4), and using various commands with a terminal emulator (Termux) on my phone, and with terminal and adb on my Linux (Ubuntu) computer with phone connected.

Command outputs appear to refer to the number (#) of blocks. By presupposing that each of these blocks has 1,024 bytes, I calculated partition sizes in MB and GB, and compared the values to the sizes of the files copied using adb pull /dev/block/bootdevice/by-name. The values matched exactly, and the total size of all of the partitions came to 32 GB, which is the size of my phone’s internal storage.

I found 62 different partitions on my phone, and combining several command outputs enabled me to produce the following table.

Partition Name	Partition Number	Number of Blocks	Partition Size MB	Partition Size GB
aboot_a	sda17	4,096	4.2
aboot_b	sda18	4,096	4.2
apdp_a	sda29	256	0.3
apdp_b	sda30	256	0.3
board_info	sdf1	16	0.0
boot_a	sda19	32,768	33.6
boot_b	sda20	32,768	33.6
bootlocker_a	sda1	512	0.5
bootlocker_b	sda2	512	0.5
cdt	sdd12	4	0.0
cmnlib32_a	sda13	256	0.3
cmnlib32_b	sda14	256	0.3
cmnlib64_a	sda15	256	0.3
cmnlib64_b	sda16	256	0.3
ddr	sdd11	1,024	1.0
devcfg_a	sda23	128	0.1
devcfg_b	sda24	128	0.1
devinfo	sdf4	4	0.0
devinfobak	sdd5	4	0.0
dip	sdd7	1,024	1.0
dpo	sdd6	4	0.0
frp	sde1	512	0.5
fsc	sdd8	4	0.0
fsg	sdf3	2,048	2.1
hosd_a	sda21	32,768	33.6
hosd_b	sda22	32,768	33.6
hyp_a	sda11	512	0.5
hyp_b	sda12	512	0.5
keymaster_a	sda3	512	0.5
keymaster_b	sda4	512	0.5
metadata	sde5	16,384	16.8
mfg	sdf2	236	0.3
misc	sdd1	1,024	1.0
modem_a	sda25	71,680	73.4
modem_b	sda26	71,760	73.4
modemst1	sdd9	2,048	2.1
modemst2	sdd10	2,048	2.1
msadp_a	sda27	256	0.3
msadp_b	sda28	256	0.3
persist	sdd3	32,768	33.6
pg1fs	sde3	4,096	4.2
pg2fs	sde4	2,048	2.1
pmic_a	sda9	512	0.5
pmic_b	sda10	512	0.5
ramdump	sde2	6,144	6.3
reserve0	sda36	4,820	4.9
reserve3	sdd13	9,020	9.2
reserve4	sde6	7,636	7.8
reserve5	sdf5	5,824	6.0
rpm_a	sda7	512	0.5
rpm_b	sda8	512	0.5
sec	sdd4	128	0.1
ssd	sdd2	8	0.0
system_a	sda33	2,097,152	2,147.5	2.1 GB
system_b	sda34	2,097,152	2,147.5	2.1 GB
tz_a	sda5	2,048	2.1
tz_b	sda6	2,048	2.1
userdata	sda35	26,038,272	26,663.2	26.7 GB
vendor_a	sda31	307,200	314.6	0.3 GB
vendor_b	sda32	307,200	314.6	0.3 GB
xbl_a	sdb1	4,052	4.1
xbl_b	sdc1	4,052	4.1
TOTALS	-	31,248,120	31,998.1	32 GB

Partition Name	Partition Number	Number of Blocks	Partition Size MB	Partition Size GB
sda	-	31,145,984	31,893.5	31.9 GB
sdb	-	4,096	4.2
sdc	-	4,096	4.2
sdd	-	49,152	50.3
sde	-	36,864	37.7
sdf	-	8,192	8.4
TOTALS	-	31,248,384	31,998.3	32 GB

The sda partition is the main part of the phone's internal storage, but could sdb, sdc, sdd, sde and sdf partitions be held on separate disks or boards?

Commands used via Phone and Terminal Emulator:

uname (with -a appended)

sudo cat /proc/partitions

tsu

sudo cat /proc/partitions

su

cd /dev/block/bootdevice/by-name

ls -all

Commands used via Computer Terminal and ADB: (I found it easier to temporarily boot TWRP using fastboot boot twrp-3.4.0-0-sailfish.img).

adb ls /dev/block/bootdevice/by-name

adb shell ls /dev/block/bootdevice/by-name

adb shell ls -all /dev/block/bootdevice/by-name

adb pull /dev/block/bootdevice/by-name (see below)

adb shell uname (with -a appended)

adb shell

cat /proc/partitions

The adb pull command copied 34.5 GB files (took 18 mins) into a ‘by-name’ file in my adb folder. The files in 'by-name' included boot (33.6 MB), system (2.1 GB) and vendor (314.6 MB) files (approx 2.5 GB) that were not included in the command outputs, which instead had similarly sized boot_a, boot_b, system_a, system_b, vendor_a and vendor_b files.