如何在运行时查找已安装和已卸载分区的总大小和可用大小

Question

I am using tune2fs -l /dev/mmcblk0p1 but when i use this command and change the free space of partition by copying some files into it , tune2fs does not gives updated values.

Tune2fs gives correct value if i restart the system but does not updates values at runtime.

Please suggest some other command that provides coreect data at runtime for unmounted/mounted partitions both.

TIA.

Answer 1

You can not get the exact value of free space available on a random unmounted block device/partition, because the actual free space will depend on actions kernel will perform when mounting the device. So the only proper way to get the amount of free space is to mount the partition first, then use the usual df utility, which will show the up to date space utilization.

However, if system crashes abruptly, the free space reported after remounting may actually be different from the value last reported by df prior to the crash.

For non-mounted devices/partitions, you can always obtain the total (but not free) space available using lsblk or similar utilities.