Okay so I ran into a situation while trying to perform a CentOS 5.5 PXE boot kickstart install on a Dell PowerEdge 2950 with a PERC6/i RAID controller along with dual LSI Logic/Symbios Logic SAS1068 Fusion-MPT SAS RAID controllers connected to two Dell MD3000 storage arrays.
The issue was in that I was wanting the operating system to install on the PERC RAID volume and not on the MD3000's but Anaconda was picking up the 8 volumes on the MD3000's (4 volumes each) and then the internal RAID volume as the 9th (/dev/sdi). All combinations and modifications I made to the kickstart config didn't seem to have any effect. The only option I was left with was to remove the SAN cable connections to the SAS1068's and install CentOS then reconnect the SAN cables and reconfigure to mount their volumes which were now being seen as /dev/sd[b-i] rather than /dev/sd[a-h].
I got around the problem this time with having to drive in and physically manage things but would have been nice to managed it remotely which is why we had the system equipped with KVM over IP and a PXE boot build network. I exhausted all my tricks and knowledge on kickstarts and CentOS installs and couldn't solve this problem but was able to navigate all the others.
Updated to include kickstart used that fails, the base repo is given in the PXE boot APPEND options as
install lang en_US.UTF-8 keyboard us network --bootproto dhcp --noipv6 --hostname centos firewall --disabled rootpw --iscrypted <encrypted passwd> text skipx authconfig --enableshadow --enablemd5 selinux --disabled timezone --utc UTC bootloader --location=mbr --driveorder=sda zerombr repo --name=updates --baseurl=http://internal.mirror.host/centos/5/updates/x86_64/ firstboot --disable services --disabled pcscd,hidd,bluetooth,pand,isdn,cups,avahi-daemon services --enabled sshd reboot ignoredisk --drives=sdb,sdc,sdd,sde,sdf,sdg,sdh,sdi,sdj,sdk,sdl,sdm clearpart --linux --drives=sda part / --fstype ext3 --size=5000 --asprimary --ondisk=sda part swap --size=8400 --ondisk=sda part /tmp --fstype ext3 --size=5000 --ondisk=sda part /opt --fstype ext3 --size=10000 --ondisk=sda part /home --fstype ext3 --size=5000 --ondisk=sda part /var --fstype ext3 --size=100 --grow --ondisk=sda %packages @base @core @system-tools @text-internet keyutils trousers fipscheck device-mapper-multipath audit