I've just 'inherited' a system that consists of a bunch of Linux servers (running Ubuntu, but probably not important) that uses iSCSI devices. These show up as /dev/sdb, /dev/sdc etc. when you log them in using the iscsiadm command.
However, the way that these devices have had filesystems formatted on them is not something I've done before, although I have heard of it. The filesystems (ext4 in this case) have been formatted directly on them, so a mkfs /dev/sdb command was probably issued. In the past I have always created partition(s) on a device using fdisk or parted, /dev/sdb1 etc., and formatted my filesystems on the partition.
Has anyone ever seen filesystems formatted directly on a device with no partitioning before and would you recommend it? Are there any reasons you might strongly argue against doing things that way?