My router is D525 with 6 gigabyte ports .
I attached 1TB 2.5 inch SATA disk which divided to 2 partitions to it.One partitions configured by LVM.
In Chaos Calmer 15.05.1:
If I use "block mount" command to mount my disk or enable fstab in startup,it will has very slow R/W speed,16.2MB/s,and the only way to umount disk is "block umount" but not "umount",if I use "umount" then show resources busy , actually I don't operate my disk
If I use "mount /dev/mapper/openwrt--lvm-data /data",it goes very well,R/W speed is 120MB/s