Optimizing Linux Systems For Solid State Disks
tytso writes "I've recently started exploring ways of configuring Solid State Disks (SSDs) so they work most efficiently in Linux. In particular, Intel's new 80GB X25-M, which has fallen down to a street price of around $400 and thus within my toy budget. It turns out that the Linux Storage Stack isn't set up well to align partitions and filesystems for use with SSD's, RAID systems, and 4k sector disks. There are also some interesting configuration and tuning that we need to do to avoid potential fragmentation problems with the current generation of Intel SSDs. I've figured out ways of addressing some of these issues, but it's clear that more work is needed to make this easy for mere mortals to efficiently use next generation storage devices with Linux."
Yeah, hard disk manufacturers.
Since they moved to large disks which require LBA, they've been fudging the CHS values returned by the drive to get the maximum size available to legacy operating systems. Since when did a disk have 63 heads? Never. It doesn't even make sense anymore when most hard disks are single platter (therefore having 1 or 2) and SSDs don't even have heads.
What they need to do is define a new command structure for accurately determining the best structure on the disk - on an SSD this would report the erase block size or so, on a hard disk, how many sectors are in a cylinder, without fucking around with some legacy value designed in the 1980's.