Find all storage devices attached to a Linux machine
You can always do fdisk -l which seems to work pretty well, even on strange setups such as EC2 xvda devices.
Here is a dump for a m1.large instance:
root@ip-10-126-247-82:~# fdisk -l
Disk /dev/xvda1: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders, total 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/xvda1 doesn't contain a valid partition table
Disk /dev/xvda2: 365.0 GB, 365041287168 bytes
255 heads, 63 sectors/track, 44380 cylinders, total 712971264 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/xvda2 doesn't contain a valid partition table
Disk /dev/xvda3: 939 MB, 939524096 bytes
255 heads, 63 sectors/track, 114 cylinders, total 1835008 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/xvda3 doesn't contain a valid partition table
While mount says:
root@ip-10-126-247-82:~# mount
/dev/xvda1 on / type ext4 (rw)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/xvda2 on /mnt type ext3 (rw)
And /proc/partitions says:
root@ip-10-126-247-82:~# cat /proc/partitions
major minor #blocks name
202 1 10485760 xvda1
202 2 356485632 xvda2
202 3 917504 xvda3
Side Note
How fdisk -l works is something I would love to know myself.
you can also try lsblk ... is in util-linux ... but i have a question too
fdisk -l /dev/sdl
no result
grep sdl /proc/partitions
8 176 15632384 sdl
8 177 15628288 sdl1
lsblk | grep sdl
sdl 8:176 1 14.9G 0 disk
`-sdl1 8:177 1 14.9G 0 part
fdisk is good but not that good ... seems like it cannot "see" everything
in my particular example i have a stick that have also a card reader build in it and i can see only the stick using fdisk:
fdisk -l /dev/sdk
Disk /dev/sdk: 15.9 GB, 15931539456 bytes
255 heads, 63 sectors/track, 1936 cylinders, total 31116288 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xbe24be24
Device Boot Start End Blocks Id System
/dev/sdk1 * 8192 31116287 15554048 c W95 FAT32 (LBA)
but not the card (card being /dev/sdl)
also, file -s is inefficient ...
file -s /dev/sdl1
/dev/sdl1: sticky x86 boot sector, code offset 0x52, OEM-ID "NTFS ", sectors/cluster 8, reserved sectors 0, Media descriptor 0xf8, heads 255, hidden sectors 8192, dos < 4.0 BootSector (0x0)
that's nice ... BUT
fdisk -l /dev/sdb
/dev/sdb1 2048 156301487 78149720 fd Linux raid autodetect
/dev/sdb2 156301488 160086527 1892520 82 Linux swap / Solaris
file -s /dev/sdb1
/dev/sdb1: sticky \0
to see information about a disk that cannot be accesed by fdisk, you can use parted:
parted /dev/sdl print
Model: Mass Storage Device (scsi)
Disk /dev/sdl: 16.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 4194kB 16.0GB 16.0GB primary ntfs
arted /dev/sdb print
Model: ATA Maxtor 6Y080P0 (scsi)
Disk /dev/sdb: 82.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 1049kB 80.0GB 80.0GB primary raid
2 80.0GB 82.0GB 1938MB primary linux-swap(v1)
ls /sys/block
/proc/partitions will list all the block devices and partitions that the system recognizes. You can then try using file -s <device> to determine what kind of filesystem is present on the partition, if any.