#Backup dockstar install
#Backup dockstar update
#Backup dockstar download

I bumped up pirsyncd's FREQ from 0 to 60 to introduce a minute-long buffer to guard a bit against this situation.

#Backup dockstar update

The subsequent rsync(s) find the flaw and update the files to the proper complete sizes. When this happens, the 'target' disk gets incomplete copies of the source's files (because the write speed to the USB drives is so slow). The only glitch is when rsync engages before a large batch of large files can be fully written to the 'source' disk. My last 3 days of testing have been pretty solid. I built an init script for pirsyncd, which I am happy to share on request, configured to sync the 2 standalone ext3-formatted 1Tb drives.I Googled 'rsync incrond subfolders', then 'rsync inotify', then 'inotify subfolders', then 'inotify subfolders rsync', which led me to 'pyinotify rsync', then 'pirsyncd'. I had only recently heard about incrond, including that incrond did not work on subfolders. I knew a cron'd rsync would work, but I wanted a more real-time mirror solution.I just wanted that the external drives would 'just work' elsewhere. But, given that these were LARGE volumes with LONG array rebuild times against REMOVABLE devices along a SLOW USB bus, I chose to adhere to the KISS (keep it simple stupid) principle and jettison my RAID aspirations, in the event I ever had to pull the disks out and connect them to another PC, Mac or other Linux system. It worked! In fact, it markedly improved core read speed from ~15Mb/s to ~22Mb/s. Despite many warnings not to, I tried a RAID mirror with 2 external USB volumes.The kcopyd LVM daemon responsible for keeping the mirror synced was eating away at the Dockstar's performance, and the LVM overhead just wasn't worth the trouble. I tried LVM mirroring, but quickly discovered that it needed either (a) a third volume to track the mirror's status, or (b) plenty of *fast* system RAM to manage the mirror.This originally meant either (a) RAID1 via mdadm, (b) LVM mirroring, or (c) cron'd rsync. I have two 1Tb external drives that I hoped to configure for some sort of fault tolerance.

#Backup dockstar download

Download and 'install' pirsyncd, a near-real-time filesystem-level mirroring daemon:.

#Backup dockstar install

Use the 'pacman' tool and resources at this URL to find and install rsync, incrond and python:.Follow the instructions here to rid the device of the Seagate-supplied firmware and replace it with Plug Linux:.The Seagate Dockstar is one of the family of so-called 'plug computers' - miniature network computers (only outfitted with power, ethernet and USB jacks in this case) that run a variant of Linux on an ARM processor with limited internal memory.

Purchase the Seagate Dockstar,, US$29.99:.My goal was to create a highly-dependable, extreme-low-power, cloud-enabled NAS (network-accessible storage) device ideally, it should guarantee against single disk failure, and should also manage off-site backup at the lowest possible recurring cost. Being a Linux groupie, though, I wanted more, for less. Carbonite, Mozy, JungleDisk, DropBox and its ilk are fantastic off-site backup services.