Re: Disk layout: OpenBSD OT
2013/3/2 Friedrich Locke : > just wonder in a typical hard drive nowadays (SATA/SAS), the sector 0 > is in the inner or outter track ? > Which tracks are faster: the inner ones or the outter ? First track is outer-most, hence faster linear transfer rates at beginning of disk, e.g. http://mralpha.s3.amazonaws.com/SAMSUNG-HD501LJ-690G-MrAlpha.png But it's generalization in terms of modern firmware. -- Michał Markowski
Re: Disk layout: OpenBSD OT
On 03/03/13 00:04, Shoufu Luo wrote: usually, the inner tracks are fast, as I know Since the RPM is constant and they can fit more data can on the outer, longer, tracks, I believe you are wrong. Not that it matters, since we don't know which ones we're served. /Alexander -Shoufu Live, Love, Laugh On Mar 2, 2013, at 14:55, Friedrich Locke wrote: Hi folks, just wonder in a typical hard drive nowadays (SATA/SAS), the sector 0 is in the inner or outter track ? Which tracks are faster: the inner ones or the outter ? Thanks in advance.
Re: Disk layout: OpenBSD OT
On Sat, Mar 02, 2013 at 10:04:50PM +0100, Matthias Appel wrote: > Am 02.03.2013 20:59, schrieb Miod Vallat: > >>just wonder in a typical hard drive nowadays (SATA/SAS), the sector 0 > >>is in the inner or outter track ? > >>Which tracks are faster: the inner ones or the outter ? > >Only the manufacturer knows. > > > >Disks have been reporting fake geometries since more than 20 years. The > >electronic on the disk will do the necessary work to use the disk > >physical characteristic (with a varying number of sector per track) as > >cleverly as it can. > > > >Nowadays, you can't even be sure a given `software' is even contiguous > >on the disk. > > > So, how is defrag (or avoiding fragmentation) done, if you can't be > certain how the blocks are aligned? You can't. You can only de-frag the 'view' the hardware provides you. You can't outsmart it, so just be happy. Ken > > AFAIK, the last blocks are on the outside of the platters so, given > a CAV, the speed is higher. > The different speeds are measurablebut I don't know if > noticeable (but I dont think so!) > > How SSDs handle block alignment is anoter story (wear-leveling et.al.) > > > Regards, > > Matthias
Re: Disk layout: OpenBSD OT
usually, the inner tracks are fast, as I know -Shoufu Live, Love, Laugh On Mar 2, 2013, at 14:55, Friedrich Locke wrote: > Hi folks, > > just wonder in a typical hard drive nowadays (SATA/SAS), the sector 0 > is in the inner or outter track ? > Which tracks are faster: the inner ones or the outter ? > > Thanks in advance.
Re: Disk layout: OpenBSD OT
Am 02.03.2013 20:59, schrieb Miod Vallat: just wonder in a typical hard drive nowadays (SATA/SAS), the sector 0 is in the inner or outter track ? Which tracks are faster: the inner ones or the outter ? Only the manufacturer knows. Disks have been reporting fake geometries since more than 20 years. The electronic on the disk will do the necessary work to use the disk physical characteristic (with a varying number of sector per track) as cleverly as it can. Nowadays, you can't even be sure a given `software' is even contiguous on the disk. So, how is defrag (or avoiding fragmentation) done, if you can't be certain how the blocks are aligned? AFAIK, the last blocks are on the outside of the platters so, given a CAV, the speed is higher. The different speeds are measurablebut I don't know if noticeable (but I dont think so!) How SSDs handle block alignment is anoter story (wear-leveling et.al.) Regards, Matthias
Re: Disk layout: OpenBSD OT
> just wonder in a typical hard drive nowadays (SATA/SAS), the sector 0 > is in the inner or outter track ? > Which tracks are faster: the inner ones or the outter ? Only the manufacturer knows. Disks have been reporting fake geometries since more than 20 years. The electronic on the disk will do the necessary work to use the disk physical characteristic (with a varying number of sector per track) as cleverly as it can. Nowadays, you can't even be sure a given `software' is even contiguous on the disk. Just trust the disk and don't try to outsmart it, for it knows more about the actual hardware than you do. Miod
Disk layout: OpenBSD OT
Hi folks, just wonder in a typical hard drive nowadays (SATA/SAS), the sector 0 is in the inner or outter track ? Which tracks are faster: the inner ones or the outter ? Thanks in advance.
