[CentOS] SCSI block device name/multipath question

hi,

i have a host with a LSI SAS 3108 RAID controller in JBOD mode with 4 
SSD SATA disks. i installed oVirt node (= CentOS 7) on the first two 
disks configured as SW RAID 1 (in the oVirt node/CentOS installer). when 
i look at the device names in the running OS i get

# lsscsi --scsi_id -g
[0:0:0:0]    disk    ATA      SAMSUNG MZ7LM480 204Q  /dev/sda   -  /dev/sg0
[0:0:1:0]    disk    ATA      SAMSUNG MZ7LM480 204Q  /dev/sdb   -  /dev/sg1
[0:0:2:0]    disk    ATA      SAMSUNG MZ7LM480 204Q  /dev/sdc 
SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102216  /dev/sg2
[0:0:3:0]    disk    ATA      SAMSUNG MZ7LM480 204Q  /dev/sdd 
SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102214  /dev/sg3

# ls -l /dev/disk/by-id/*SAMSUNG*
lrwxrwxrwx. 1 root root  9  9. Okt 12:07 
/dev/disk/by-id/ata-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102212 -> ../../sdb
lrwxrwxrwx. 1 root root 10  9. Okt 12:07 
/dev/disk/by-id/ata-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102212-part1 -> 
../../sdb1
lrwxrwxrwx. 1 root root 10  9. Okt 12:07 
/dev/disk/by-id/ata-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102212-part2 -> 
../../sdb2
lrwxrwxrwx. 1 root root  9  9. Okt 12:07 
/dev/disk/by-id/ata-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102214 -> ../../sdd
lrwxrwxrwx. 1 root root  9  9. Okt 12:07 
/dev/disk/by-id/ata-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102216 -> ../../sdc
lrwxrwxrwx. 1 root root  9  9. Okt 12:07 
/dev/disk/by-id/ata-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102222 -> ../../sda
lrwxrwxrwx. 1 root root 10  9. Okt 12:07 
/dev/disk/by-id/ata-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102222-part1 -> 
../../sda1
lrwxrwxrwx. 1 root root 10  9. Okt 12:07 
/dev/disk/by-id/ata-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102222-part2 -> 
../../sda2
lrwxrwxrwx. 1 root root 10  9. Okt 12:07 
/dev/disk/by-id/dm-name-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102214 -> 
../../dm-6
lrwxrwxrwx. 1 root root 10  9. Okt 12:07 
/dev/disk/by-id/dm-name-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102216 -> 
../../dm-5
lrwxrwxrwx. 1 root root 10  9. Okt 12:07 
/dev/disk/by-id/dm-uuid-mpath-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102214 
-> ../../dm-6
lrwxrwxrwx. 1 root root 10  9. Okt 12:07 
/dev/disk/by-id/dm-uuid-mpath-SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102216 
-> ../../dm-5

disks 2:0 + 3:0 are configured as multipath devices (and subsequently 
set up by device mapper), disks 0:0 + 1:0 are not. 
SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102216 and 
SAMSUNG_MZ7LM480HMHQ-00005_S2UJNX0J102214 are listed in 
/etc/multipath/wwids (and get re-listed after reboot when i manually 
remove them).

why are two of the four local disks configured as multipath devices? As 
far as i understood documentation this shouldn't happen

thx 4 help
matthias