Messages in this thread | | | From | Jim Meyering <> | Subject | Re: tools support for non-512 byte sector sizes | Date | Wed, 30 Jul 2008 19:16:49 +0200 |
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Matt Domsch <Matt_Domsch@dell.com> wrote: > On Tue, Jul 29, 2008 at 02:48:31PM -0400, Martin K. Petersen wrote: ... >> Just yesterday I received a couple of prototype drives in the mail. >> I'll ask the vendor whether they support 4KB and if so I'll give them >> a whirl. > > I have access to disks with native 4KB sectors now too. Would
Do they expose that sector size? I.e., does ioctl(fd,BLKSSZGET,&ss) set ss to 4096?
I'm interested because I'm preparing GNU Parted's partition table manipulation code (not its FS code) for just that. In particular, now I've heard two stories:
- disk makers will eventually sell drives with >512-byte sectors
- some disk makers have sort of agreed not to do that, and expect forever to hide the larger underlying sector size behind a virtual 512 (of course, this imposes alignment restrictions, but that's a smaller problem)
Even if the latter is the case, we still have to deal with optical and flash, both of which can already have larger sectors.
> interested parties be willing to share test plans, so we could be sure > we have coverage wrt correctness: kernel internals, userspace tools like parted, > fdisk, kpartx, apps using O_DIRECT)? Benchmarking winds up being an > NDA activity this early in the game so I don't want the focus of any > joint work to be benchmarks yet.
Speaking of O_DIRECT, both dd and shred (both in coreutils), use O_DIRECT, so you could get _some_ coverage just by running shred and experimenting with dd's oflag=direct and iflag=direct options.
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