I've made such a hash of configuring an external RAID enclosure on a RHEL6 box, I've got to the point where I don't know how I actually got to where I am now!
Anyway, I think I have it working now, but I would like some help understanding something.
In my very limited experience of installing disks under linux before, I have just seen them as /dev/sda, /dev/sdb etc, then created partitions which appear as /dev/sda1, /dev/sda2 etc.
Dmesg shows my device as sdc:
[root@db2 backups]# grep sdc /var/log/dmesg
sd 6:0:0:0: [sdc] 3509329920 512-byte logical blocks: (1.79 TB/1.63 TiB)
sd 6:0:0:0: [sdc] Write Protect is off
sd 6:0:0:0: [sdc] Mode Sense: 77 00 10 08
sd 6:0:0:0: [sdc] Write cache: disabled, read cache: enabled, supports DPO and FUA
sd 6:0:0:0: [sdc] Attached SCSI disk
I created a partition but attempting to format /dev/sdc1 resulted in errors. Eventually, by looking at /proc/partitions, I noticed an entry /dev/dm-0.
Now I understand this is something to do with the drive mapper, but that's all I know!
I have been able to format and use it so I guess it's working okay, but could a kind soul please explain, or speculate, why my device has appeared as /dev/dm-0 and not /dev/sdc1?