First we are going to configure our RAID-5 array, and then install Openfiler on our system disk. The install process is long; it took about eight hours, largely waiting and more waiting. Have that music handy.
With Openfiler, you can go with software RAID, which requires processor muscle, especially with potentially twenty drives. The catch here is that as far as I know, there are no 20 port SATA motherboards. So you’d have to buy several SATA HBAs. Given the price of our 3Ware board, you’d end up paying more for less performance.
Stick with a quality used, processor-based RAID card (unlike High Point or Promise, which are more like RAID hardware assist cards) and you’ll get a highly reliable and performant solution. The downside is that you are tightly coupling your data to a hardware vendor. While RAID is standard, the checksum mechanism is proprietary to each vendor, such as 3Ware in our case.
The setup of the 3Ware card held no gotchas, and required just a few decisions, documented in Figure 9. I created a single unit of all nine drives as RAID 5. The largest decision is the stripe size and I went with the largest, 256K. I also selected write cacheing. Even without battery backup, power is not an issue here and my use patterns mean critical data loss is very unlikely. The Hitachi drives support NCQ, so drive queuing is enabled. We are going for performance, so I used the Performance profile, natch.
Figure 9: 3Ware RAID array configuration
There are long running discussions and mysteries associated with the selection of stripe size and its impact on performance. There is a complex calculus around drive speed, number of drives, average file size, bus speed, usage patterns and alike. Too much for me - I used the simplistic rule of thumb, “Big files, big stripes, little files, little stripes.” I plan on using the array for large media files. This decision, stripe size, does impact our performance as you'll see later.
Once you’ve configured the array, you’ll be asked to initialize the unit. Initialization can take place in the foreground or the background and the first time through I recommend doing it front and center. This allows you to see if there are any issues around your drives. But it does require patience - it took about six hours to initialize all the drives, and waiting for 0% to tick over to 1% is a slow drag. If you choose, you can cancel, and it will take even longer in the background.
Have your Openfiler Version 2.3 install CD (2.99 isn’t quite ready for primetime), downloaded from SourceForge, sitting in the server’s DVD drive so that once the RAID initialization is complete, it will boot.
Given the age of the 3ware card, and LSI’s acquisition of them, docs can take awhile to find. There are several useful PDF files available, linked below for your convenience.
Openfiler is a branch of RedHat Linux and is a breeze to install. Boot from CD. You have the choice of Graphical Installation or Text Installation. Installation directions are at Openfiler.com.
The simplest is the Graphical install (Figure 10) and you’ll be stepped through a set of configuration screens: Disk Set-up; Network Configuration; and Time Zone & Root Password.
Unless you have unique requirements, such as mirroring of your boot disk, select automatic partitioning of your system disk (usually /dev/sda). Be careful to not select your data array; the size difference makes this easy.
Automatic partitioning will slice your system disk into two small partitions, /Boot and Swap – allocating the remaining space for your root directory (“/”). You should probably go no smaller than a 10 GB disk for your system disk.
Figure 10: Openfiler disk setup
For network setup (Figure 11), you can choose either DHCP or manual. With DHCP you’re done. Manual is no more difficult than basic router configuration. You’ll need an IP address, netmask, DNS server IPs and a gateway IP.
Figure 11: Openfiler network setup
Unless you are in one of those time zones that are oddball (for example Arizona), setting the time zone is just a matter of point and click on a large map. Zeroing in on a tighter location can be a pain.
Your root password, not that of the Web GUI, should be an oddball secure password. Once set you’ll see the commit screen shown in Figure 12.
Figure 12: Openfiler install confirmation screen
Once you hit the Next button it is time to go out for a sandwich—it took more than an hour to format the system disk, and download and install all the needed packages.
When complete, you will get a reboot screen. Pop the media out of the drive and reboot, we have a couple more steps.
Once Openfiler is up, you’ll see the Web GUI address - note it, we’ll need it in the next section. Log in as root with your newly-set password, we are going to do a full update of the system software and change the label of the RAID array.
The version of Linux, rPath, uses a package management tool call conary. To bring everything up to date, we will do a updateall, by entering the following line at the command prompt:
This update for Old Shuck took about twenty minutes.
Once complete, we just need to change the label of the RAID array, which for some mysterious reason, Openfiler defaults to msdos, limiting our volume size to no more than 2 TB. The label needs to be changed to gpt via this command:
parted /dev/sdb mklabel gpt
Make sure you change the label on the correct volume! mklabel will wipe a disk, which can be useful for starting over, but catastrophic for your system disk.
After rebooting our prepped and updated Old Shuck, we are ready to do the NAS configuration, which means making a journey through Openfilers Web GUI.