Getting the CCISS RAID controller to work on EL7
As you may have gathered, I really like RHEL 7 and its clones. I have run into one problem though. In Chapter 24 of the RHEL 7 Release Notes they enumerate quite a bit of hardware that they have dropped support for. Included are about 3 pages of RAID controllers and some NICs. I have a few HP Proliant DL380 G5 servers at work that have the HP Smart Array P400 RAID Controller in them and they are no longer officially supported with the release of RHEL 7.0. They work just fine with RHEL 5 and RHEL 6. HP actually has drivers that they provide for RHEL 5 and RHEL 6 but almost no one uses them because the hardware just worked with the stock RHEL kernels. Since the G5 machines (that's generation 5 not PowerPC G5) are 6 or 7 years old now, HP has stopped providing firmeware updates nor will they be providing drivers for newer Linux distros.
Just to verify, I booted one of the servers with the RHEL 7 install DVD and nope... it says there are no hard disks available. :(
The devs over at ElRepo have saved my day. I filed a request for enhancement (RFE) in their Mantis bug tracker system asking if they could build the CCISS driver package for the EL7 kernel. I had an answer within a hour or two... and a test package within a couple of hours. If you aren't familiar with ElRepo, they are a fairly popular third-party repo for EL. Not quite as popular as the Fedora Project's EPEL repo though. One thing ElRepo specializes in is drivers.
I do recommend staying away from third-party repos and drivers as much as possible but given the fact that the stock RHEL 7 installer says my servers have no hard drives I was stuck. If you don't have any hard drives, you can't do an install. I have never had to use a driver disk with the RHEL installer but I guess such things exist. Not being familiar with them, I just took the kmod-cciss package the ElRepo dev built, copied it to my local repository, added it to the package list of my CentOS LiveDVD kickstart file. Then I used livecd-creator to build a LiveDVD. My personal respin includes GNOME, KDE, Firefox, LibreOffice, GIMP, Inkscape, virt-manager, SPICE, etc... and now the ElRepo kmod-cciss package as well. After building the ISO I burned it to DVD and booted a problem server with it. Bingo, EL7 sees the controller and the disks attached to it now.
Not having used third-party drivers much in the past I was fairly ignorant about them. There are kmod, akmod, and dkms type driver packages. Do you know the differences between them? I mean with something as important to the operation of the system as RAID controller that presents all disks to the system... you don't want it breaking when you upgrade the kernel, right? It is my understanding that kmod-based packages aren't tired to a specific build of the kernel. So the kmod-cciss package I got from ElRepo should (in theory) work with every kernel update for EL 7.0 that comes out. When EL 7.1 comes out, it'll probably be a slightly different branch... and before trying to switch to future 7.1 kernels, I'd probably need to update the kmod-cciss package... or at least that is my understanding.
Anyway, so far it is working great. We'll see if I have any regrets as time goes by. I will definitely take care to be very aware of when kernel updates get installed and always keep a known-to-work kernel around just in case.