[HTC Sensation] astar26:
Hello Fellow Sensation Owners!

A couple of days ago someone asked about the Sensation's internal storage layout, which got me curious, as we get 1GB of storage to data partition, about 700MB for system, and where does all the rest go? boot is just a couple of megabytes, and firmware (combined), is 400MB.

When I searched google for it, I couldn't find any mention of the Sensation's partition layout, and barely found how to get it by myself. So here I am, creating this mention/guide (for future people who like me want to know what the partition layout is).

To get the layout and sizes, I used the df command in the shell, which gives a nice table with all (mounted) partitions, with information about them.

The results I got were:

Filesystem Size Used Free Blksize
/dev 271.7M 52K 271.6M 4096
/storage 271.7M 0K 271.7M 4096
/vendor/firmware/misc 199.8M 21.5M 178.3M 4096
/vendor/firmware/adsp 199.8M 5.7M 194.1M 4096
/mnt/secure 271.7M 0K 271.7M 4096
/mnt/asec 271.7M 0K 271.7M 4096
/mnt/obb 271.7M 0K 271.7M 4096
/mnt/fuse 271.7M 0K 271.7M 4096
/system 787.4M 388.8M 398.6M 4096
/data 1.1G 482.1M 693.9M 4096
/cache 118.1M 98M 20.1M 4096
/devlog 19.7M 14.8M 4.9M 4096
/storage/sdcard0 14.8G 13G 1.8G 32768
/mnt/secure/asec: Permission denied
/mnt/asec/com.quoord.tapatalkxda.activity-1 5M 3.2M 1.8M 4096

Note: I got this list on Cyanogenmod 10.1, a different ROM might bring
different results.

There are a few points of interest here:

1) There are 5 empty partitions, 271.7MB each.

2) Apps stored on the SD card are listed as individual partitions - in my case - XDA app (also tested on Sony Ericsson Live With Walkman - same result).

3) /mnt/secure/asec needs root access to be read, and after enabling, it seems to be mounted to the same space as the sdcard. this partition is actually the Android_secure foldier on the SD Card. This makes me suspect that some of the empty partitions are also mounts of the same partition from different directories inside it.

4) My suspition is most probably wrong, as the sum of all partition sizes amounts to about 4GB, which is what listed on the spec sheet.

5) /boot partition is not listed, which makes me believe some more are not actually mounted.

To know if there are double-mounted partitions, I checked the mount list on /proc/mounts by using this command:

[B]CAT /proc/mounts[/B]

I will post points of interest I found as It's quite long and mostly messy:

rootfs / rootfs ro,relatime 0 0
tmpfs /dev tmpfs rw,nosuid,relatime,mode=755 0 0
devpts /dev/pts devpts rw,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
tmpfs /storage tmpfs rw,relatime,mode=050,gid=1028 0 0
/dev/block/mmcblk0p17 /vendor/firmware/misc vfat ro,relatime,fmask=0000,dmask=0000,allow_utime=0022,codepage=cp437,iocharset=iso8859-1,shortname=lower,errors=remount-ro 0 0
/dev/block/mmcblk0p19 /vendor/firmware/adsp vfat ro,relatime,fmask=0000,dmask=00
00,allow_utime=0022,codepage=cp437,iocharset=iso8859-1,shortname=lower,errors=re
mount-ro 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
tmpfs /mnt/secure tmpfs rw,relatime,mode=700 0 0
tmpfs /mnt/asec tmpfs rw,relatime,mode=755,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,relatime,mode=755,gid=1000 0 0
tmpfs /mnt/fuse tmpfs rw,relatime,mode=775,gid=1000 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
/dev/block/mmcblk0p22 /system ext4 ro,relatime,user_xattr,barrier=1,data=ordered
,noauto_da_alloc 0 0
/dev/block/mmcblk0p23 /data ext4 rw,nosuid,nodev,noatime,user_xattr,barrier=1,data=ordered,noauto_da_alloc 0 0
/dev/block/mmcblk0p24 /cache ext4 rw,nosuid,nodev,noatime,user_xattr,barrier=1,data=ordered,noauto_da_alloc 0 0
/dev/block/mmcblk0p28 /devlog ext4 rw,nosuid,nodev,noatime,user_xattr,barrier=1,data=ordered,noauto_da_alloc 0 0

We can see something interesting - /mnt/secure, /mnt/asec, /mnt/obb, /mnt/fuse, /storage and /dev are all mounted from tmpfs, which is not an adress on the mmc. I have no Idea what this means, but it explains all those partitions seen before - They are the same space (probably like /mnt/secure/asec - folders inside a bigger partition).

This thread is meant for me (and probably other curious users) to understand how the sensation is formatted.

Also, to keep a clean explanation of what each partition actually is (for begginers and to have it organized), here is a list of partitions with explanations about them (all those I know are included, some are basic knowledge, list will be updated).

/data - where your apps and basically all your data that is stored on the device is

/system - where system apps, frameworks, and the rest of the OS is (excluding kernel)

/boot (not listed) - kernel

/storage/sdcard - no need to be imaginative here - the SD card

/mnt/secure/asec - the android_secure folder on sdcard

/cache - app cache - where temporary data is stored to speed up apps

What I'm trying to do here is to create a clear and comprehensive explanation of the Sensation's NAND layout, so anyone looking for it could find it. For non-devs it's of not much use, but nice to know. Also to keep a clear way to check it on other devices (had to dive to linux websites to find some stuff here).

Would be glad if someone more knowledgeable than I am would add/correct me here, to make this helpfull.

To your Enjoyment/feeding your interest.