Linux调整磁盘分区大小

Posted 2022-12-14 Sonictl

Resize the disk （Linux调整磁盘分区大小）

Resize the partition. Run parted: $ parted

Show the partition list: (parted) print

There should be two partitions; 1 should be a boot partition, about 64MB; the second should be the main partition, about 3.6G

Some Disk Commands of Linux, that you should know：

• sudo df -h          Display the FileSystem that you mounted
• sudo fdisk -l    Show your disk information that is unmounted or un-parted

Sonictl: Here I didn't see two partitions by print command. but fdisk -l showed me that.

Resize the second partition to use the whole disk: (parted) resizepart 2 32GB

Sonictl: Here you may meet error: "Unrecognized disk label", useselect command to chang the device from "/dev/mmcblk1boot0" to "/dev/mmcble0", then try again.


Close parted: (parted) quit

Reboot to load the updated partition table: $ reboot

Log in as root again, resize the filesystem: $ resize2fs /dev/mmcblk0p2

Now you should have the full capacity of your microSD card available.

for some reason, you may meet: resize2fs: Permission denied to resize filesystem, you can fix this by Link:Manually Resize on Linux PC

======= above seems works well for Lubuntu/ubuntu =======

For most Embedded OS(raspbian/lubuntu/...), ref: Manually resizing the SD card on Raspberry Pi

======== for calculating the Cylinder# ========

Make a new partition with the exact size you got from the block count. Since you cannot enter block size in fdisk, you need to figure out how many cylinders to request. Here is the formula:

(number of needed cylinders) = (number of blocks) / (block size) (block size) = (unit size) / 1024 (unit size) = (number of heads) * (number of sectors/cylinder) * (number of bytes/sector)

Consider the following example, where a hard drive has been partitioned into four primary partitions of 1, 2, 4, and 8 cylinders.

disk /dev/sda: 16 heads, 63 sectors, 23361 cylinders Units = cylinders of 1008 * 512 bytes Device Boot Start End Blocks Id System /dev/sda1 1 2 976+ 83 Linux /dev/sda2 3 5 1512 83 Linux /dev/sda3 6 10 2520 83 Linux /dev/sda4 11 19 4536 83 Linux

fdisk

provides the configuration information I need in the head of the output. The unit size is 516096 ( 16 heads * 63 sectors/cyl * 512 bytes/sector ). The block size is 504 ( 516096 / 1024 ). The number of needed cylinders for the second partition is therefore 3 ( 1512 blocks / 504 ). The partition table shows that this is indeed the case: the first cylinder is 3, the second 4, and the last is 5, for a total of three cylinders. The number of needed cylinders for the third partition is calculated similarly: 2520 blocks / 504 = 5, which corresponds to blocks 6,7,8,9,10 . Notice that this calculation does not work for the first partition because the block count is wrong ( 976 instead of 1008 ). The plus sign indicates that not all the blocks are included in the fdisk value. When you try the calculation ( 976 / 504 ) you get 1.937. Knowing that the number of cylinders must be an integer, you can simply round up.