[lug] IDE Raid Array Mini-Review 3Ware 7000-2

[Sexton, George]

Here's the follow up to my earlier RAID card review for ATA.

My latest purchase was a 3Ware 7000-2 RAID controller. This is a 2 port
Ultra-133 IDE Raid controller that supports RAID 0 and RAID 1. Unlike the
Promise and HPT series, this controller provides true hardware raid. It is
part of their family that includes ATA controllers that go up to 12 ports
for parallel or serial ATA. This particular model was purchased for $120
from PC Mall.

Installation of the controller was very simple. After booting the machine, I
entered the BIOS setup and configured the raid array to be a 2 drive RAID 1
(mirrored) array using a pair of Maxtor 80GB Ultra 133 drives.

Next, I booted into RedHat 7.2 (with all patches and updates applied). A
simple modprobe of the 3w-xxxx modules, and I had a new SCSI disk visible on
my system. The 3w-xxxx module has been a part of the Linux kernel source
tree since 2.2.15. Virtually any distribution should be able to use this
controller. I partitioned the array into one large ext2 partition.

I went to the 3Ware site and downloaded their monitoring daemon. After
unzipping the file, I ran the installation shell script. The 3Ware Daemon
was installed and started automatically. The 3Ware monitoring daemon is a
web-based UI that gives complete control over the raid array. Using a web
browser and the monitoring daemon, you can view the status of your arrays,
re-build arrays, etc. You can also view details about the array, including
the firmware revisions of drives, drive serial numbers, etc. It is well laid
out and easy to use. The only hitch was that the monitoring daemon listens
on port 1080. Netscape and Mozilla by default block access to servers
running on these ports. This is well documented, and just required a minor
modification to the all.js file in the /usr/lib/mozilla/prefs directory.
Finally, the monitoring daemon allows you to also configure Email
notification of events. You can specify the mail server, mail from, and mail
to names.

As a test, I downloaded a kernel source tree onto the partition and started
running a kernel build. While the kernel was compiling, I unplugged the
power connector from one of the two drives. The kernel compile continued
without any problems. Immediately, notification emails were sent informing
me that the array was running in degraded mode. The Email messages had very
clear and explicit instructions on things to check and how to recover the
array.

I then cleanly shut down the machine and rebooted Linux. Using the web based
GUI, I attempted to rebuild the array. After the second time, I stopped and
read the error messages the software gave. The web GUI provided excellent,
step by step instructions to tell me how to rebuild the array. For the 3rd
try, I read the instructions and started the rebuild. While the rebuild was
running, the web GUI gave status updates showing the percent completed for
the rebuild.

Finally, when the rebuild completed Email notifications were sent saying the
array was running in regular mode. While the pair was rebuilding, CPU and
I/O on the Linux machine were virtually zero. As expected, I/O to the raid
array was noticeably slower while the rebuild was running.

Conclusions

If you are looking for true hardware based fault tolerance at a really
excellent price, this is a hot buy. The monitoring and configuration tools
are first rate and work perfectly. My only minor gripe is that I would like
to see a transducer on the controller card to provide audible notification
of a drive failure. This is minor complaint since the monitoring daemon does
provide notification via Email.



George Sexton
MH Software, Inc.
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