To my knowledge Ubuntu creates a system reserve on partitions that take up 5% of the partition capacity. On 8 TB drives system reserve takes up about 380 gigs. I double checked this in df and can calculate the missing gigs. I have four 8 TB partitions and am losing 1.5 TB of storage space. Is there a way to make ubuntu use a smaller percentage for the system reserve?
2 Answers
mkfs.ex4
to create a linux ext4
file system
When you use mkfs.ext4
you will create a new file system (and the data in the partition will be lost). You must backup all data, that you cannot afford to lose, before doing it.
You can use the option -m
to specify the reserved percentage, for example to get 3%,
sudo mkfs.ex4 -m 3 /dev/sdxn
where x is the device letter and n is partition number, for example /dev/sda1
.
From man mkfs.ex4
-m reserved-blocks-percentage
Specify the percentage of the filesystem blocks reserved for the
super-user. This avoids fragmentation, and allows root-owned
daemons, such as syslogd(8), to continue to function correctly
after non-privileged processes are prevented from writing to the
filesystem. The default percentage is 5%.
tune2fs
to modify a linux ext4
file system
When you use tune2fs
you will modify an existing file system (and the data in the partition should be preserved). But you should backup all data, that you cannot afford to lose, before doing it.
You can use the option -m
to specify the reserved percentage, for example to get 3%,
sudo tune2fs -m 3 /dev/sdxn
where x is the device letter and n is partition number, for example /dev/sda1
.
Yes and you can change the percentage on each disk with the following parameters Example:
sudo tune2fs -m 0 /dev/sda1
where 0 is percentage size
sudo tune2fs -l /dev/sda1 | grep 'Reserved block count'
check reserved block count