Increase /tmp size

I need to sort 7 GB txt file and extract uniq lines. PC has OMV on 4 core CPU and 16 Gb RAM. And i supposed it will be enough because file size less than available memory, however after executing

# sort -u 7GB.txt > testsort.txt

sort: write failed: /tmp/sortjpzocK: No space left on device

I tried to increase /tmp by adding below line in /etc/fstab

tmpfs     /tmp     tmpfs     defaults,size=25G,mode=1777     0     0

but it does not work after reboot, i still got 7.3G /tmp

root@media:~# df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            7.3G     0  7.3G   0% /dev
tmpfs           1.5G  2.6M  1.5G   1% /run
/dev/nvme0n1p2  467G  199G  245G  45% /
tmpfs           7.3G   84K  7.3G   1% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           7.3G     0  7.3G   0% /tmp
/dev/nvme0n1p1  511M  152K  511M   1% /boot/efi

However if i need temporary increase, it works

root@media:~# mount -o remount,size=25G /tmp/
root@media:~# df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            7.3G     0  7.3G   0% /dev
tmpfs           1.5G  2.6M  1.5G   1% /run
/dev/nvme0n1p2  467G  199G  245G  45% /
tmpfs           7.3G   84K  7.3G   1% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs            25G     0   25G   0% /tmp
/dev/nvme0n1p1  511M  152K  511M   1% /boot/efi

I know that i may tell sort to use another folder to keep temp files for its work but i wish to increase /tmp permanently.

Zitat von ryecoaaron

tmpfs defaults to half of your ram. How much ram does your system have?

16 GB, and /tmp therefore 7.3Gb

Zitat von BlueCoffee

This might help pal. Option 2

Yeah i read it and also tried to put

tmpfs /tmp tmpfs rw,nodev,nosuid,size=25G 0 0

it does not work. Seems /tmp size configured according to RAM somewhere, and ignored fstab value.

Zitat von ryecoaaron

Since setting tmpfs to larger than your ram is going to swap at some point, why not just tell sort to use a temp dir other than something using tmpfs?

I got two option either set external /tmp or temporary increase /tmp. But i wondering why it's not working in fstab

reboot done