In real estate it's about location. In storage it's about capacity. The next crop of high density drives are available but there are some gotchas related to some 3TB drives that you need to know before making a land grab.
Other Operating Systems
As previously mentioned, Linux kernels are already able to handle LBA 64-bit addressing. Linux can also handle 4KB sector drives as well. So all of the smart people using Linux are ready to use the new drives (with some caution that I will mention later) but unfortunately, “other” operating systems are not ready. Since there are the occasional times we are forced to deal with these operating systems, let’s take a look at the problems/issues, and what can be done (or not done) to help/fix them (in other words, let’s find the crutches we need to make them work with 3TB drives).
Several operating systems have switched to something called the GPT or GUID Partition Table as the layout mechanism on drives instead of the MBR (Master Boot Record) layout. It has been used on certain system BIOS for a while but it is part of Intel’s EFI (Extensible Firmware Interface) that is being promoted for new systems. GPT’s are 64-bit making our life a lot easier.
But the key issue is that your BIOS much support GPT to boot from a GPT enabled drive. In the consumer world this is a downside since most motherboards don’t have a BIOS that is GPT capable. This can affect all operating systems including Linux.
In addition to the BIOS, you also need to make sure your SATA controllers can also work with 64-bit LBA addressing. According to this article, Intel storage drives don’t support 64-bit LBA but running your ICH in Native IDE mode will work. According to the same site, the reason that Western Digital is including a SATA card with the new drives is to allow systems to use the 3TB drives since the card has a controller that is known to work with large drives. Be sure to check the specifications on your SATA controller to determine if it can work with GPT oriented drives.
But don’t feel too bad if your system doesn’t have an EFI BIOS or a BIOS that can handle GPT drives and doesn’t have a SATA controller that can handle large drives. These limitations just mean that you can’t boot from the 3TB drives. If your SATA controller can’t handle the larger drives you can still use them as a secondary or non-bootable drive that are typically used for non-OS data. The good news for the Linux world is that the SATA controller that comes with the drive can work with Linux and the 3TB drives, so we really don’t have any restrictions in using the 3TB drives as secondary drives. However, we are likely to be limited in using the drives as a boot drive – the same as everyone else because of the BIOS issue.
But there are likely to be factors affecting our choice of operating system. Figure 1, from Western Digital, shows the details on using the new 3TB drive as a boot drive or secondary drive with various OS’s.
Figure 1: OS compatibility chart for new Western Digital 3TB drive
We all feel the need for speed and large capacity storage and we don’t need to attend AA-esque meetings to admit it. Western Digital is the first company to offer a 3TB SATA drive that is focused on the consumer market. Their drive comes with a SATA controller to help existing systems take advantage of the 3TB of lovely storage capacity goodness if they meet other criteria (such as a SATA controller than can handle larger drives).
In addition to 3TB’s of capacity, this new drive also switches over to 4KB sectors. This switch offers increased capacity that is available for formatting compared to the more common 512 byte sectors. It can also help improve performance of the drive itself although some of the extra performance comes when the drive has bad sectors (a scenario we all want to avoid). In the meantime, the drive provides a 512-byte “compatibility” mode for older LBA oriented operating systems.
Linux is ready for 4KB drive sectors with 64-bit LBA addressing. Many SATA drivers are ready as well and Linux is even GPT ready, but the general consumer hardware world is not. The needed components should be ready in early 2011 (we’re hoping). The enterprise world may be a bit better off but you need to check on the motherboards in your servers. If they are using EFI you have cleared one hurdle. You can install Linux and boot from the drive but be sure you use the correct tools to handle GPT (i.e. “fdisk” is not a good idea). There are a number of sites that explain how to do this. If not, you can still use the 3TB drives if your SATA controller is ready, but only as secondary (i.e. non-bootable) storage (not a bad thing).
One last comment – since the appearance of the Western Digital 3TB drive, others have appeared. For example, the Hitachi Deskstar H3IK30003272SW has appeared. On newegg, as of the writing of this article, the drive retailed for $199.99. What is interesting about this drive is that it is a SATA III (6.0 Gbps) drive running at 7,200 rpm with a very large 64MB cache. I think that 2011 will see the combination of SATA III (6.0 Gbps), 3TB drives, and GPT tools becoming typical for systems especially since Intel is releasing new processors as is AMD. It’s going to be a great year Lewis.
Jeff Layton is an Enterprise Technologist for HPC at Dell. He can be found lounging around at a nearby Frys enjoying the coffee and waiting for sales (but never during working hours).