Thor Lancelot Simon wrote:
On Mon, Jan 11, 2010 at 05:21:41PM -0800, John Nemeth wrote:Although at one time it was common to be able to format drives with different sector sizes, that was over two decades ago. It is doubtful that any current operating system would be happy with a hard drive that had a sector size other than 512 bytes. Thus they can't change that until current OSes become an historical footnote.You're kidding, right? Maybe, again, you should stop speaking whereof you know not. Just as one example (which accounts for the large number of SCSI/FC/SAS disk drives one still finds on the surplus market which are formatted for 524 byte sectors): http://publib.boulder.ibm.com/infocenter/dsichelp/ds6000ic/index.jsp?topic=/com.ibm.storage.smric.help.doc/f2c_reformattingopensddms_1v5bpp.html It may not be an operating system you use, but it's certainly still a current one.
Well, technically any disk will have more than 512 bytes of data for each sector. It's just that 512 bytes is what is presented to (and usable by) the host system, and those disks by IBM are no different. They still present 512 byte sectors to the host OS. To quote the page you linked to: "The data portion of the sector remains at 512-bytes for all host systems." What underlying format is used, and what data the controller stores and uses, to make sure the host is serviced with the correct, and fault free data, is of little concern here. We are not, after all, making disk controllers, are we?
However, the age of random block sizes for disks (exposed to the OS) is way more than 2 decades back.
I'd say that would be about 4 decades ago, and maybe more.Oh, and I don't expect the 512 bytes/block paradigm to change any time soon. It's probably one of those things we will live with for ever. The underlying disks might start doing something else, but you'll probably still be able to see, and treat the disk as if it had 512 byte blocks for as long as we live.
Just my two cents...
Johnny
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