friendly ping... CC:bug-parted@gnu.org On 2020/6/1 9:56, Zhiqiang Liu wrote: > Hi: > Now I parted a disk with command “parted /dev/sdb -s mkpart primary 0cyl > 128cyl” > but the result was unexpected. The partition started 512 kB but not expected > 1 MB. > What’s more, the size of partition was 33.4 MB but not expected 1 GB. The > commands are as follows, > 1. dd if=/dev/zero of=/dev/sdb bs=1M count=10 > 2. parted /dev/sdb -s mklabel msdos > 3. parted /dev/sdb -s mkpart primary 0cyl 128cyl > ->Warning: The resulting partition is not properly aligned for best > performance: 1s % 2048s != 0s > > After analysis, the reason of size changed was that cylinder’s size was > changed. > And the reason of starting position changed was that partition could not align > by 2048 sectors. When partition tried to align 2048 sectors, the end sector of > partition could not be in range of [127.5, 128.5) *cyl, which didn’t meet > command “128cyl”. > > I found that one patch for parted/libparted/arch/linux.c as show in > https://dcantrel.fedorapeople.org/patches/parted/0001-Use-BLKSSZGET-to-get-device-sector-size-in-_device_p.patch > is > related with the problem. ioctl (arch_specific->fd, BLKSSZGET, §or_size) > are used to get dev->bios_geom.sectors, > which changes from 63 to (1 + sector_size/PED_SECTOR_SIZE_DEFAULT). > > The patch has changed the cylinder’s size, and using cyl to align partitions > will always fail. > However, I do not have any idea to solve the problem. Could you help me? > > Best regards. > Zhiqiang Liu >
