Log-structured file systems: There's one in every SSD

Posted Sep 20, 2009 20:48 UTC (Sun) by dwmw2 (subscriber, #2063)
In reply to: Log-structured file systems: There's one in every SSD by dlang
Parent article: Log-structured file systems: There's one in every SSD

"keep in mind that the same hardware standardization that you are blaming microsoft for is the same thing that let linux run on standard hardware."

Nonsense. Disk controllers aren't standardised — we have a multitude of different SCSI/IDE/ATA controllers, and we need drivers for each of them. You can't boot Linux on your 'standard' hardware unless you have a driver for its disk controller, and that's one of the main reasons why ancient kernels can't be used on today's hardware. Everything else would limp along just fine.

The disks, or at least the block device interface, might be fairly standard but that makes no real difference to whether you can run Linux on the system or not. It does help you share file systems between Linux and other operating systems, perhaps — but that's a long way from what you were saying.

NAND flash is fairly standard, although as with disks we have a multitude of different controllers to provide access to it. And even the bizarre proprietary things like the M-Systems DiskOnChip devices, with their "speshul" formats to pretend to be disks and provide INT 13h services to DOS, can be used under Linux quite happily. You don't need to implement their translation layer unless you want to dual-boot (although we have implemented it). You can use the raw flash just fine with flash file systems like JFFS2.

Log-structured file systems: There's one in every SSD

Posted Sep 20, 2009 23:28 UTC (Sun) by dlang (guest, #313) [Link]

_now_ linux has support for a huge number of devices.

but think about when linux started. at that point in time it started out with ST506 MFM support and vga video support.

that wasn't enough to drive the hardware optimally, but it was enough to talk to it.

similarly with the IDE/SATA controllers, most of them work with generic settings, but to get the most out of them you want to do the per-controller tweaks.

even in video, the nvidia cards can be used as simple VGA cards and get a display.

the harder you make it to get any functionality the harder it is to get to the point where the system works well enough to be used and start being tuned.