FYI, we noticed the below changes on https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master commit 216076705d6ac291d42e0f8dd85e6a0da98c0fa3 ("dm thin: disable discard support for thin devices if pool's is disabled") [ 19.907521] md: Waiting for all devices to be available before autodetect [ 19.908422] md: If you don't use raid, use raid=noautodetect [ 19.911745] md: Autodetecting RAID arrays. [ 19.912384] md: Scanned 0 and added 0 devices. [ 19.913020] md: autorun ... [ 19.913525] md: ... autorun DONE. [ 19.914227] RAMDISK: gzip image found at block 0 [ 20.373805] RAMDISK: incomplete write (14363 != 28156) [ 20.374568] write error [ 20.592977] FAT-fs (ram0): utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive! [ 20.594607] FAT-fs (ram0): utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive! [ 20.597157] VFS: could not find a valid V7 on ram0. [ 20.598143] ufs: ufs was compiled with read-only support, can't be mounted as read-write [ 20.599302] VFS: Cannot open root device "ram0" or unknown-block(1,0): error -30 [ 20.600365] Please append a correct "root=" boot option; here are the available partitions: [ 20.601521] 0100 65536 ram0 (driver?) [ 20.602267] 0101 65536 ram1 (driver?) [ 20.602996] 0102 65536 ram2 (driver?) [ 20.603720] 0103 65536 ram3 (driver?) [ 20.604450] 0104 65536 ram4 (driver?) [ 20.605177] 0105 65536 ram5 (driver?) [ 20.605911] 0106 65536 ram6 (driver?) [ 20.606653] 0107 65536 ram7 (driver?) [ 20.607379] 0108 65536 ram8 (driver?) [ 20.608106] 0109 65536 ram9 (driver?) [ 20.608826] 010a 65536 ram10 (driver?) [ 20.609565] 010b 65536 ram11 (driver?) [ 20.610317] 010c 65536 ram12 (driver?) [ 20.611052] 010d 65536 ram13 (driver?) [ 20.611782] 010e 65536 ram14 (driver?) [ 20.612522] 010f 65536 ram15 (driver?) [ 20.613271] fb00 268435456 vda driver: virtio_blk [ 20.614084] fb10 268435456 vdb driver: virtio_blk [ 20.614876] fb20 268435456 vdc driver: virtio_blk [ 20.615670] fb30 268435456 vdd driver: virtio_blk [ 20.616471] fb40 268435456 vde driver: virtio_blk [ 20.617271] fb50 268435456 vdf driver: virtio_blk [ 20.618081] 1600 4194302 hdc driver: ide-cdrom [ 20.618867] 1f00 4096 mtdblock0 (driver?) [ 20.619637] 1f01 131072 mtdblock1 (driver?) [ 20.620428] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(1,0) [ 20.621566] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.3.0-rc1-00001-g2160767 #1 [ 20.622638] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 20.623836] 0000000000000000 ffff88009b2d3de0 ffffffff8173de06 ffffffff83a8abb1 [ 20.625167] ffff88009b2d3e60 ffffffff811a401f 0000000000000010 ffff88009b2d3e70 [ 20.626500] ffff88009b2d3e08 ffffffff811a0031 ffff88009b2d3e78 ffff88009b2cc860 [ 20.627832] Call Trace: [ 20.628271] [] dump_stack+0x4b/0x63 [ 20.628981] [] panic+0xce/0x20f [ 20.629651] [] ? SYSC_perf_event_open+0x61d/0x9d9 [ 20.630483] [] mount_block_root+0x20f/0x226 [ 20.631260] [] mount_root+0x153/0x15c [ 20.631990] [] ? initrd_load+0x2d4/0x2e3 [ 20.632744] [] prepare_namespace+0x16c/0x1a4 [ 20.633539] [] kernel_init_freeable+0x25f/0x274 [ 20.634360] [] ? rest_init+0x140/0x140 [ 20.635097] [] kernel_init+0xe/0xdf [ 20.635806] [] ret_from_fork+0x3f/0x70 [ 20.636541] [] ? rest_init+0x140/0x140 [ 20.637342] Kernel Offset: disabled Elapsed time: 40 Thanks, Ying Huang