[HTC Sensation] david.f.girault:
FYI, I made a full logcat during boot time.

dg@bureau:~$ grep -i -e vold -e mount -e mtp cm13_boot.log
11-16 09:29:34.694 I/vold ( 183): Vold 3.0 (the awakening) firing up
11-16 09:29:34.695 V/vold ( 183): Detected support for: ext4 f2fs vfat
11-16 09:29:34.860 V/vold ( 183): /system/bin/sgdisk
11-16 09:29:34.860 V/vold ( 183): --android-dump
11-16 09:29:34.860 V/vold ( 183): /dev/block/vold/disk:179,64
11-16 09:29:35.041 V/vold ( 183): DISK gpt 499DDCDD-1853-4DF7-9A8D-F017A2B156A3
11-16 09:29:35.041 V/vold ( 183): PART 1 19A710A2-B3CA-11E4-B026-10604B889DCF F66F9F38-DC46-4144-99BE-EE93320316B4 android_meta
11-16 09:29:35.041 V/vold ( 183): PART 2 193D1EA4-B3CA-11E4-B075-10604B889DCF 782DF28B-3FCA-8487-3AD9-1B5980A073D6 android_expand
11-16 09:29:35.046 D/vold ( 183): Found key for GUID 782df28b3fca84873ad91b5980a073d6
11-16 09:29:43.053 D/MtpDeviceJNI( 225): register_android_mtp_MtpDevice
11-16 09:30:10.179 I/SystemServiceManager( 579): Starting com.android.server.MountService$Lifecycle
11-16 09:30:10.205 D/MountService( 579): Thinking about reset, mSystemReady=false, mDaemonConnected=true
11-16 09:30:10.207 D/MountService( 579): Thinking about reset, mSystemReady=false, mDaemonConnected=true
11-16 09:30:10.211 W/MountService( 579): No primary storage mounted!
11-16 09:30:10.212 D/VoldConnector( 579): SND -> {1 asec list}
11-16 09:30:10.213 D/VoldConnector( 579): RCV <- {200 1 asec operation succeeded}
11-16 09:30:10.505 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:10.507 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:10.509 W/MountService( 579): No primary storage mounted!
11-16 09:30:10.509 D/VoldConnector( 579): SND -> {2 asec list}
11-16 09:30:10.510 D/VoldConnector( 579): RCV <- {200 2 asec operation succeeded}
11-16 09:30:13.269 D/MountService( 579): Thinking about reset, mSystemReady=true, mDaemonConnected=true
11-16 09:30:13.269 D/VoldConnector( 579): SND -> {3 volume reset}
11-16 09:30:13.270 I/ActivityManager( 579): Force stopping com.android.providers.media appid=10009 user=-1: vold reset
11-16 09:30:13.271 D/VoldConnector( 579): RCV <- {651 emulated 7}
11-16 09:30:13.271 E/vold ( 183): private:179,66 failed to revert cryptfs
11-16 09:30:13.271 D/VoldConnector( 579): RCV <- {659 emulated}
11-16 09:30:13.271 D/VoldConnector( 579): RCV <- {650 emulated 2 "" ""}
11-16 09:30:13.271 V/vold ( 183): /system/bin/sgdisk
11-16 09:30:13.271 V/vold ( 183): --android-dump
11-16 09:30:13.271 D/VoldConnector( 579): RCV <- {651 emulated 0}
11-16 09:30:13.272 V/vold ( 183): /dev/block/vold/disk:179,64
11-16 09:30:13.272 D/VoldConnector( 579): RCV <- {651 private:179,66 7}
11-16 09:30:13.272 D/VoldConnector( 579): RCV <- {659 private:179,66}
11-16 09:30:13.272 D/VoldConnector( 579): RCV <- {649 disk:179,64}
11-16 09:30:13.272 D/VoldConnector( 579): RCV <- {640 disk:179,64 7}
11-16 09:30:13.273 D/VoldConnector( 579): RCV <- {641 disk:179,64 15931539456}
11-16 09:30:13.273 D/VoldConnector( 579): RCV <- {642 disk:179,64 SanDisk}
11-16 09:30:13.273 D/VoldConnector( 579): RCV <- {644 disk:179,64 /sys//devices/platform/msm_sdcc.3/mmc_host/mmc1/mmc1:e624/block/mmcblk1}
11-16 09:30:13.397 V/vold ( 183): DISK gpt 499DDCDD-1853-4DF7-9A8D-F017A2B156A3
11-16 09:30:13.397 V/vold ( 183): PART 1 19A710A2-B3CA-11E4-B026-10604B889DCF F66F9F38-DC46-4144-99BE-EE93320316B4 android_meta
11-16 09:30:13.397 V/vold ( 183): PART 2 193D1EA4-B3CA-11E4-B075-10604B889DCF 782DF28B-3FCA-8487-3AD9-1B5980A073D6 android_expand
11-16 09:30:13.400 D/vold ( 183): Found key for GUID 782df28b3fca84873ad91b5980a073d6
11-16 09:30:13.401 D/VoldConnector( 579): RCV <- {650 private:179,66 1 "disk:179,64" "782DF28B-3FCA-8487-3AD9-1B5980A073D6"}
11-16 09:30:13.401 D/VoldConnector( 579): RCV <- {651 private:179,66 0}
11-16 09:30:13.401 D/VoldConnector( 579): RCV <- {643 disk:179,64}
11-16 09:30:13.401 D/VoldConnector( 579): RCV <- {200 3 Command succeeded}
11-16 09:30:13.402 D/VoldConnector( 579): SND -> {4 volume user_added 0 0}
11-16 09:30:13.403 D/VoldConnector( 579): RCV <- {200 4 Command succeeded}
11-16 09:30:13.404 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:13.434 D/VoldConnector( 579): SND -> {5 volume mount private:179,66 0 -1}
11-16 09:30:13.436 V/vold ( 183): /system/bin/blkid
11-16 09:30:13.436 V/vold ( 183): -c
11-16 09:30:13.436 V/vold ( 183): /dev/null
11-16 09:30:13.436 V/vold ( 183): -s
11-16 09:30:13.436 V/vold ( 183): TYPE
11-16 09:30:13.436 V/vold ( 183): -s
11-16 09:30:13.436 V/vold ( 183): UUID
11-16 09:30:13.436 V/vold ( 183): -s
11-16 09:30:13.436 V/vold ( 183): LABEL
11-16 09:30:13.436 V/vold ( 183): /dev/block/vold/private:179,66
11-16 09:30:13.436 D/VoldConnector( 579): RCV <- {651 private:179,66 1}
11-16 09:30:13.486 I/ActivityManager( 579): Start proc 694:com.android.externalstorage/u0a10 for broadcast com.android.externalstorage/.MountReceiver
11-16 09:30:13.512 I/blkid ( 692): type=1400 audit(0.0:67): avc: denied { getattr } for path="/dev/block/vold/private:179,66" dev="tmpfs" ino=10077 scontext=u:r:blkid:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.550 V/vold ( 183): /dev/block/vold/private:179,66: UUID="2f2eb83c-d00f-4d2a-8d62-616426b8f138" TYPE="ext4"
11-16 09:30:13.552 D/VoldConnector( 579): RCV <- {652 private:179,66 ext4}
11-16 09:30:13.553 D/VoldConnector( 579): RCV <- {653 private:179,66 2f2eb83c-d00f-4d2a-8d62-616426b8f138}
11-16 09:30:13.553 D/VoldConnector( 579): RCV <- {654 private:179,66 }
11-16 09:30:13.553 D/VoldConnector( 579): RCV <- {655 private:179,66 /mnt/expand/2f2eb83c-d00f-4d2a-8d62-616426b8f138}
11-16 09:30:13.572 I/ActivityManager( 579): Start proc 721:android.process.media/u0a9 for broadcast com.android.providers.media/.MtpReceiver
11-16 09:30:13.522 I/blkid ( 692): type=1400 audit(0.0:68): avc: denied { read } for name="private:179,66" dev="tmpfs" ino=10077 scontext=u:r:blkid:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.522 I/blkid ( 692): type=1400 audit(0.0:69): avc: denied { open } for name="private:179,66" dev="tmpfs" ino=10077 scontext=u:r:blkid:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.522 I/blkid ( 692): type=1400 audit(0.0:70): avc: denied { ioctl } for path="/dev/block/vold/private:179,66" dev="tmpfs" ino=10077 ioctlcmd=1272 scontext=u:r:blkid:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.614 D/Vold ( 183): Running /system/bin/e2fsck on /dev/block/vold/private:179,66
11-16 09:30:13.614 V/vold ( 183): /system/bin/e2fsck
11-16 09:30:13.614 V/vold ( 183): -y
11-16 09:30:13.614 V/vold ( 183): /dev/block/vold/private:179,66
11-16 09:30:13.642 I/e2fsck ( 738): type=1400 audit(0.0:71): avc: denied { getattr } for path="/dev/block/vold/private:179,66" dev="tmpfs" ino=10077 scontext=u:r:fsck:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.642 I/e2fsck ( 738): type=1400 audit(0.0:73): avc: denied { read } for name="private:179,66" dev="tmpfs" ino=10077 scontext=u:r:fsck:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.692 I/e2fsck ( 183): /dev/block/vold/private_179,66: clean, 76/972944 files, 110333/3885179 blocks
11-16 09:30:13.711 D/vold ( 183): private:179,66 passed filesystem check
11-16 09:30:13.728 V/vold ( 183): Starting restorecon of /mnt/expand/2f2eb83c-d00f-4d2a-8d62-616426b8f138
11-16 09:30:13.642 I/e2fsck ( 738): type=1400 audit(0.0:74): avc: denied { open } for name="private:179,66" dev="tmpfs" ino=10077 scontext=u:r:fsck:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.642 I/e2fsck ( 738): type=1400 audit(0.0:75): avc: denied { write } for name="private:179,66" dev="tmpfs" ino=10077 scontext=u:r:fsck:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.642 I/e2fsck ( 738): type=1400 audit(0.0:76): avc: denied { ioctl } for path="/dev/block/vold/private:179,66" dev="tmpfs" ino=10077 ioctlcmd=127c scontext=u:r:fsck:s0 tcontext=u:object_r:vold_device:s0 tclass=blk_file permissive=1
11-16 09:30:13.858 V/vold ( 183): Finished restorecon of /mnt/expand/2f2eb83c-d00f-4d2a-8d62-616426b8f138
11-16 09:30:13.860 D/VoldConnector( 579): RCV <- {650 emulated:179,66 2 "" ""}
11-16 09:30:13.870 D/VoldConnector( 579): RCV <- {651 emulated:179,66 0}
11-16 09:30:13.870 D/VoldConnector( 579): RCV <- {651 private:179,66 2}
11-16 09:30:13.870 D/VoldConnector( 579): RCV <- {200 5 Command succeeded}
11-16 09:30:14.025 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.029 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.038 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.042 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.132 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.133 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.142 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.145 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.150 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:14.161 D/MtpService( 721): starting MTP server in MTP mode
11-16 09:30:15.510 D/StorageNotification( 686): partGuid=782DF28B-3FCA-8487-3AD9-1B5980A073D6 mountFlags=0 mountUserId=-1
11-16 09:30:15.510 D/StorageNotification( 686): state=MOUNTED
11-16 09:30:15.513 D/StorageNotification( 686): type=PRIVATE diskId=null partGuid=null mountFlags=0 mountUserId=-1
11-16 09:30:15.513 D/StorageNotification( 686): state=MOUNTED
11-16 09:30:17.290 D/MountService( 579): onStartUser 0
11-16 09:30:17.290 D/VoldConnector( 579): SND -> {6 volume user_started 0}
11-16 09:30:17.291 D/VoldConnector( 579): RCV <- {200 6 Command succeeded}
11-16 09:30:20.532 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:20.534 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:24.582 D/VoldCryptCmdListener( 183): cryptfs getpw
11-16 09:30:24.606 D/VoldCryptCmdListener( 183): cryptfs clearpw
11-16 09:30:28.650 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:28.900 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:32.126 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:32.129 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:38.443 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:38.624 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:38.632 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:38.636 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:38.638 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:38.649 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:38.653 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:39.085 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:39.088 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:43.920 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:43.937 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:44.590 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:44.594 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:44.624 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:44.658 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:44.660 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:44.664 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:46.253 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:30:58.714 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:19.007 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:19.023 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:22.374 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:22.377 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:22.437 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:22.498 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:22.524 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:43.944 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:31:44.028 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:35:42.140 W/MountService( 579): No primary storage defined yet; hacking together a stub
11-16 09:35:42.144 W/MountService( 579): No primary storage defined yet; hacking together a stub

If someone have some advice to help me.

So I will try also sd-ext mod to put dalvik cache in data partition and data in sd-ext. Leaving second partition of sd card in legacy mode...

Don't hesitate to request more debug information. I'm a dev (I've already commited in CM7 long time ago)...