Category Archives: RAID

Areca RAID cards and WDC desktop-class HDDs (non-RE)

First of all, avoid any green drives (including WDC RE-GP drives) at all cost for RAID setups.

I have Areca’s ARC-1210 and ARC-1220 RAID cards installed on my Tyan servers (with S5397 and S5211 motherboards).  Some of these servers are using WDC GP drives (my vendor ordered the GP drives), despite having TLER-enabled, they will drop from the RAID sets within days or weeks.  Enabling TLER does help, but don’t count too much on it.  This is caused by the IntelliPower feature that limits its RPM to 5400.  RAID drives are supposed to be fast, GP drives are slow.

Few weeks ago I tried to get a pair of WDC WD2500AAJS-22VTA0 to run Windows Server 2003 R2 Standard Edition.  The installation went well until few days of uptime, the server rebooted itself after showing this error message:

The instruction at “0x76946203” referenced memory at “0x76946203”. The required data was not placed into memory because of an I/O error status of “0xc000000e”. Click on OK to terminate the program.

Prior to this error message, it showed a yellow popup (like the low disk space popup) on the systray but I couldn’t get a screenshot as it happened really fast.  It states (IIRC) that files are missing/corrupted in the RECYCLER folder.

I tried disabling write cache on the RAID card and Windows, but no luck.  Tried to enable TLER (it wasn’t on before), also no luck.  Finally I consulted Google and found out that disabling NCQ help on some hard drives.  I disabled NCQ and rebooted the server, so far it has been up for almost a month.  Before this, it couldn’t even reach a week of uptime.

Now I use the WDC RE3 drives (WD5002ABYS) to replace the GP drives.  The temperature of the RE3 drives are much lower (8-10C lower) than the desktop drives, despite having less cooling in the room.

Hopefully this post can help others to avoid the issues I encountered.

Painfully slow CentOS system

Today I was installing CentOS 5.2 to a Tyan barebone server with Intel Xeon X3220 processor, 2GB of RAM, and 2 Western Digital SATA II 250GB HDD. I chose to use software RAID 1 for my /boot and /. I didn’t create RAID 1 for swap partition because it is useless and in fact it might slow down performance. It took more than 2 hours to complete the whole installation process even when I used bare minimum packages selection. The format process of / partition itself took quite a while to complete.

Once the installation was complete, it rebooted and I found a painfully slow newly-installed CentOS system. The keyboard response was slow as if I were connected to a remote server with 1 second latency. I wasn’t happy because this is a quad-core processor server with acceptable amount of RAM. When I looked at /proc/mdstat to see how the software RAID is doing, I noticed that the sync speed is only around 1000KB/s. I tried looking for solutions on Google and found this and this. The solution I got didn’t help increase the sync speed, nor the slow response I was getting typing on the console or remotely.

I then somehow managed to find another possible solution. I can’t remember how I finally got this solution (thanks to nixCraft/CyberCiti). I didn’t notice that the hard drives were actually detected as hdX (IDE/PATA) instead of sdX (SATA). Now this makes sense because PATA is much slower than SATA. It turned out to be an issue with the hardware detection process. Somehow CentOS detected the HDDs and used PATA driver instead of SATA driver, so the devices were named hdX and treated as PATA hence the slow sync speed. I made the BIOS changes as mentioned in the solution and attempted another install, it was REALLY fast this time and the software RAID 1 sync speed was over 70000KB/s.

References:
http://www.centos.org/modules/newbb/viewtopic.php?topic_id=16178
http://lists.centos.org/pipermail/centos/2005-February/002068.html
http://www.ducea.com/2006/06/25/increase-the-speed-of-linux-software-raid-reconstruction/
http://www.cyberciti.biz/faq/linux-sata-drive-displayed-as-devhda/
http://www.nodeofcrash.com/?p=57