Advanced format disk

[Zhu Han]

On Mon, Nov 7, 2011 at 10:44 PM, Martin Rusko <martin.rusko at gmail.com>wrote:

> On Mon, Nov 7, 2011 at 3:12 AM, Zhu Han <schumi.han at gmail.com> wrote:
> > Hi,
> >
> > I got several advanced format disk, whose physical size is 4096 bytes,
> but
> > its logical size is 512 bytes:
> > $ sudo fdisk -l /dev/sdb
> >
> > Disk /dev/sdb: 750.2 GB, 750156374016 bytes
> > 255 heads, 63 sectors/track, 91201 cylinders
> > Units = cylinders of 16065 * 512 = 8225280 bytes
> > Sector size (logical/physical): 512 bytes / 4096 bytes
> > I/O size (minimum/optimal): 4096 bytes / 4096 bytes
> > Disk identifier: 0x00000000
> >
> > Disk /dev/sdb doesn't contain a valid partition table
> >
> > Is there any special tuning knob I should notice before formating it?
> IMHO,
> > set the sector size as 4096 bytes is enough. The default block size is
> 4096
> > bytes.
> > $ sudo xfs_info /dev/sdb
> > meta-data=/dev/sdb         isize=256    agcount=4, agsize=45785912 blks
> >                   =                       sectsz=4096  attr=2
> > data          =                       bsize=4096   blocks=183143646,
> > imaxpct=25
> >                   =                       sunit=0      swidth=0 blks
> > naming      =                        version 2              bsize=4096
> > ascii-ci=0
> > log            =internal               bsize=4096   blocks=89425,
> version=2
> >                  =                       sectsz=4096  sunit=1 blks,
> > lazy-count=1
> > realtime   =none                   extsz=4096   blocks=0, rtextents=0
> >
> >
>
> One thing is to make sure, that your partitions are aligned to
> physical sector size. Recent fdisk will do it properly. See options
> '-c' (or 'c' in interactive mode) which sets DOS compatibility mode
> and '-u' (or 'u' in interactive mode) which sets units which fdisk
> uses. You want no DOS compatibility and units of sectors. Then first
> partition starts on 2048 sector (so 1MiB is available for GRUB for
> example) and it's gets things nicely aligned ... 2048 logical sectors
> = 256 physical sectors.
>

If the whole disk is used for the file system (it is not a bootable disk so
no partition is created), can I ignore these settings safely?


>
> If you are creating more than one partition, use something like +34G
> while specifying end of the partition (so the next one is aligned as
> well).
>
> Martin
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://oss.sgi.com/pipermail/xfs/attachments/20111107/491b019f/attachment.htm>