Flayol Frédéric submitted on our project page link to his interesting project, he setup Raid 1 file system with two USB Flash drives.
There are also many other interesting projects on his blog!
olimex
all fun projects at Olimex Ltd
all fun projects at Olimex Ltd
06 Nov 2015 1 Comment
in Learning, linux, project, tutorial Tags: file, olinuxino, raid, system
Flayol Frédéric submitted on our project page link to his interesting project, he setup Raid 1 file system with two USB Flash drives.
There are also many other interesting projects on his blog!
olimex 
Nov 06, 2015 @ 23:06:43
On a system with an A10 or A20 a RAID-1 made of one SATA and an USB disk would make much more sense to store data. The typical sequential performance for USB and SATA is 30/30 and 40/100 (write/read) when using 2.5″ disks. So it’s a good idea to use the ‘–write-mostly’ switch when creating the RAID so that writes go to both disks but only the SATA disk that is way faster will be used to read from. With mainline kernel the situation improves both regarding throughput as well as flexibility. The best approach with mainline kernel and a RAID-1 containing of USB and SATA is to make use of the UAS protocol, to use mdadm to create the array with reads only from the faster SATA disk and put btrfs with ‘-o noatime,compress=lzo’ mount options on top of it. Some people think about using cheap port multipliers and RAID on the A20. While it might work the whole idea is crap and renders the idea of RAID useless.
Some background informations:
http://linux-sunxi.org/USB/UAS
http://linux-sunxi.org/SATA#Performance
http://forum.lemaker.org/forum.php?mod=redirect&goto=findpost&ptid=11857&pid=71617