I need to mount my secound ssd drive to /home2.I already created the folder /home2 - Now, how can i figure out which is the unused drive ?Is this /dev/sda or sdb ?What is the exactly thing i`ve to look for to know which is the unmounted drive ?[/]# cat /proc/mdstatPersonalities : [raid1]md1 : active raid1 sdb2[1] sda2[0]      524224 blocks super 1.0 [2/2] [UU]md0 : active raid1 sdb1[1] sda1[0]      16777088 blocks super 1.0 [2/2] [UU]md2 : active raid1 sdb3[1] sda3[0]      217125312 blocks super 1.0 [2/2] [UU]unused devices: <none>df -hFilesystem      Size  Used Avail Use% Mounted on/dev/md2        204G   84G  111G  44% /tmpfs            16G     0   16G   0% /dev/shm/dev/md1        496M   53M  419M  12% /boot/usr/tmpDSK     1.9G   94M  1.7G   6% /tmproot@kas [~]# fdisk -l | grep '^Disk'Disk /dev/sdb: 240.1 GB, 240057409536 bytesDisk identifier: 0x0007b22fDisk /dev/sda: 240.1 GB, 240057409536 bytesDisk identifier: 0x000c0cf1Disk /dev/md2: 222.3 GB, 222336319488 bytesDisk identifier: 0x00000000Disk /dev/md0: 17.2 GB, 17179738112 bytesDisk identifier: 0x00000000Disk /dev/md1: 536 MB, 536805376 bytesDisk identifier: 0x00000000root@kas [~]# fdisk -lDisk /dev/sdb: 240.1 GB, 240057409536 bytes255 heads, 63 sectors/track, 29185 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x0007b22fDevice Boot Start End Blocks Id System/dev/sdb1 1 2089 16777216+ fd Linux raid autodetect/dev/sdb2 2089 2155 524288+ fd Linux raid autodetect/dev/sdb3 2155 29186 217125464+ fd Linux raid autodetectDisk /dev/sda: 240.1 GB, 240057409536 bytes255 heads, 63 sectors/track, 29185 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000c0cf1Device Boot Start End Blocks Id System/dev/sda1 1 2089 16777216+ fd Linux raid autodetect/dev/sda2 2089 2155 524288+ fd Linux raid autodetect/dev/sda3 2155 29186 217125464+ fd Linux raid autodetectDisk /dev/md2: 222.3 GB, 222336319488 bytes2 heads, 4 sectors/track, 54281328 cylindersUnits = cylinders of 8 * 512 = 4096 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000Disk /dev/md0: 17.2 GB, 17179738112 bytes2 heads, 4 sectors/track, 4194272 cylindersUnits = cylinders of 8 * 512 = 4096 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000Disk /dev/md1: 536 MB, 536805376 bytes2 heads, 4 sectors/track, 131056 cylindersUnits = cylinders of 8 * 512 = 4096 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000
Mount a second ssd drive on centos - How can I figure out which is the unused drive?
linux;centos;mount;ssd
Both SSDs are already fully committed to your three RAID-1 partitions.  You don't have any free space on either of them.Edit: yes, that is what I am saying.  The df output shows you that /dev/md[12] are mounted (I'm guessing /dev/md0 is swap; /cat /proc/swaps will confirm that).  cat /proc/mdstat then tells you that /dev/mdN is a RAID-1 made up of /dev/sdaN+1 and /dev/sdbN+1, for N=0,1,2.The fdisk output confirms this by showing us that each disc is completely filled by three RAID-autodetect partitions.