HPA, Host Protected Area

I’m a big fan of technology that helps users. HPA could be one of those “helpful” technologies. HPA is a “feature” of some motherboards whereby they steal hard disk space (typically the last few megs of your disk) and use it for backing up the system BIOS, a recovery partition, etc.

I just purchased a GIGABYTE GA-EP45-UD3P motherboard, RAM, and CPU to drop into my file server. Today I assembled the trio, stripped my old mobo out and dropped this new one in.

The machine booted up but there was a little problem. Two of my disks (members of a ZFS mirror) were corrupted!?  That effectively destroyed one of my filesystems, which made me very unhappy.

A few Google searches later and I learned all about HPA. This nasty little surprise was tucked away in Advanced BIOS Features -> Dual BIOS Recover Source = HPA (page 49,51 in the manual). My version of BIOS doesn’t have this option, but I found accounts online of older versions that do. It seems that changing that setting didn’t actually work (ie, disable HPA), so Gigabyte removed the feature. They have left me no way of disabling this destructive feature.

After hours of fiddling, I have worked around it by:  a) moving the disks off the first two SATA connectors b) rebooting onto the HDD GURU Magic Boot ISO, c) removing the HPA partition from both disks, d) rebooting into FreeBSD. Finally, my ZFS mirror was back with one disk, because the motherboard had helpfully restored the HPA on the first disk.

If you’re using this mobo and migrating disks to it, I’d suggest installing a sacrificial disk on the first SATA controller. That will appease the HPA demon and let you successfully migrate your RAID volumes to it. I’m stuck moving the data off the disk I recovered. Then I’ll recreate the array on the disks with the HPA partition and all will be well.

Strawberry Ice Cream

It all begins with fresh local strawberries. Add in some fresh cream, a mother’s love, a churn it in the Cuisinart Ice Cream Machine. It doesn’t get any better than this.

Is it worth upgrading to the iPhone 3GS?

Short answer: yes.

Longer answer: Absolutely!

Hillbilly answer: You betcha!

Beancounter answer: I purchased my first iPhone 4GB (2G) in Oct 2007 for $300, direct from Apple. Today, I sold it on Craigslist for $225. I purchased my 16GB iPhone 3G for $300 in July 2008. That phone is about to get sold on Craigslist as well, for about $375. My cost to own for both iPhones is $0. I expect to sell my 32GB iPhone 3GS next year, for more than I paid. It’s an unbeatable deal.

Geek answer: The combination of a faster processor and more RAM makes a huge difference. I would bet the RAM is contributing more than the faster CPU. A good analogy would be using OS X with 1GB of RAM and then upgrading to 2GB (just enough). With the memory pressure relieved, nearly everything is more responsive.

The previous iPhones lagged when switching apps, [re]loading web pages, and especially when taking and saving photos. All those little pauses are gone. Switching back and forth between apps is nearly instantaneous. That alone is worth upgrading for. Seriously.

But I upgraded for the better camera. The previous iPhone camera was quite poor. The 3GS camera is not yet good, but certainly better.