ext4 performance tweaking: how to confirm data=writeback is in effect?
by chconnor from LinuxQuestions.org on (#5FG7N)
Hi -- I'm experimenting with various ext4 settings on an SSD (SATA).
/etc/fstab has:
Code:UUID=1234 / ext4 noatime,data=writeback,barrier=0,nobh,commit=60,errors=remount-ro 0 1...but that makes the system not boot (an error relating to remounting with different journal mode) unless I also do:
Code:# tune2fs -o journal_data_writeback /dev/sda2...now the system boots, but I don't see "data=writeback" here:
Code:$ findmnt /dev/sda2
TARGET SOURCE FSTYPE OPTIONS
/ /dev/sda2 ext4 rw,noatime,nobarrier,errors=remount-ro,commit=60How can I tell if data=writeback has taken effect?
Thanks!


/etc/fstab has:
Code:UUID=1234 / ext4 noatime,data=writeback,barrier=0,nobh,commit=60,errors=remount-ro 0 1...but that makes the system not boot (an error relating to remounting with different journal mode) unless I also do:
Code:# tune2fs -o journal_data_writeback /dev/sda2...now the system boots, but I don't see "data=writeback" here:
Code:$ findmnt /dev/sda2
TARGET SOURCE FSTYPE OPTIONS
/ /dev/sda2 ext4 rw,noatime,nobarrier,errors=remount-ro,commit=60How can I tell if data=writeback has taken effect?
Thanks!