8408E configuration and management
Before we get into performance numbers on the card and drives, there's the matter of its management software to examine. We'll start with the BIOS.
Yup, that's the BIOS. It's a full-on GUI, with mouse support (we were using a PS/2 mouse). It's not the prettiest UI ever created, but it doesn't get in the way of usability.
All of the important configuration operations can be performed in the BIOS, from RAID creation to problem-solving to performance policies.
The GUI on the MegaRAID BIOS facilitates the easy use of its numerous features, allowing for OS-independent configuration changes, provided you're willing to take the system offline to do them.
Of course, that's not necessary at all, because the RAID card and its arrays can be managed through the operating system. The management software is Java-based, which means, driver permitting, it's not fussed about the platform it's running on; excellent news for compatibility.
When installed, the user must login using a valid username and password. In our case, we installed the software in standalone mode, allowing us to use one of the computer's local logins, however the same software can be used over a network, for managing multiple remote machines.
A wizard makes configuration easy, even using manual configuration.
For most of our testing we left the majority of settings the same, though we did have to cut back on the array size (more on that on the next page).
Enabling write-back caching warned us that no battery was present. With write-back caching, data to be written is kept in the card's RAM and sent to disk at a later time. This can speed up operation in some circumstances, but a power-out can lead to data loss if no battery backup is present.
Operations on the RAID array take up disk and controller time. If a system needs to be online all of the time a balance between speed of operation and speed of online access needs to be found. By default RAID operations get 30% of the duty cycle.
That said, a rebuild didn't look as though it was going to take that long, though the story might have been different if the disks were under heavy load.
It's important to realise that the BIOS GUI and management software are just tools with which to tell the controller what to do. The management software doesn't do any of it, it just lets you get and set stuff. If a disk dies and you replace it, the controller will happily rebuild using it without any intervention.
For even more control, a command line interface, (MegaCLI) is downloadable. It's a little strange to get used to, but offers a massive set of configuration options.
We could spend a lot longer on the features of the card. Sufficient to say it has some very nice management tools, although the fact that it's Java-based does make the interface a little bit sluggish at times. Still, it's empowering and informative, and also quite easy to use to boot.
