On Mon, Nov 7, 2011 at 3:12 AM, Zhu Han <schumi.han@xxxxxxxxx> 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 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 _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
