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Raid a Dual Slot HDD Docking Station

Nov 22, 2015   //   by wvanbusk   //   Technology  //  Comments Off on Raid a Dual Slot HDD Docking Station

This is likely the least expensive external two drive hardware raid 0 or 1 solution out there with an esata port. In this case, raid 1 is used to reduce the chance of losing data on a low power home server used to backup and provide added storage for a personal web site and ultrabooks with ssd drives. The media server also contains photos and videos from many years of travel. The server host is a low power ubuntu laptop that stays on all the time and the drives only spin down if the system is deliberately put to sleep or shut off. Otherwise the two WD red 3tb drives are always on as samba based NAS in a toaster like configuration.cavalry dual dock

The WD reds were originally selected for their low power usage and decent performance. Filling the drives with a transfer from a single usb 3 2tb backup hdd through the server, the OS reported average transfer speeds of around 65MB/s over several hours of writing of a mixture of files sizes using gnome desktop drag and drop. The transfer speed in this system is in approximate agreement with formal reviews of wd red elsewhere. The drives stay warm but are relatively quiet in operation. I expect the two drives are using about 1 watt on standby and around 18 watts when idle, reading or writing based on reviews. I don’t expect much there is much power draw from the docks controller chipset.cavalry dual dock sockets

cavalry powerThe host server is running Ubuntu Mate 64bit and the drives were formatted using gparted to ext4. The raid on the dock is self configuring and the OS is presented with a single 3tb volume with the id of the jmicron raid chip jmb352. No driver is required for this sata device. The individual drives are not accessible with the exception that SMART information is presented for what looks like one of the drives in linux smartctl. gsmartThe jmb352 is very capable and was used, for example, in WD mybook products, however there have been issues with some implementations due to a few inferior quality products. Examination of the review distributions, on Amazon, of example, can reveal sellers with high prevalence of defective (one star) docks.

Since this is not an enclosure but is, rather, an exposed dock or open bay, it does not have or need a cooling fan to ventilate the drives. The circuit board of the controller is protected, but the hdd controller boards are exposed and could be damaged if you were to poke at them with a sharp stick. The reason for an enclosure for hdds is to protect the circuitry from accidental damage. Once enclosed, heat buildup should be eliminated with a powered fan. It may be that hdd life can be extended if kept cooled to ambient temperature, or below. The lack of an enclosure helps air to circulate around the drives at the risk of possible damage and accidental unplugging. There is a risk of damage if the drives will be spilled out of the bay when the table is upset or the human, cat or dog knocks it over landing the bare drives on the floor.tool-free

An omission in the design of most docks are ways to lock them in place. Tool free enclosures use a caddy or pins that fit into the standard mounting holes in the frame of the drive and rails of a chassis. Three point five inch desktop drives have standard screw holes in the usual places all around the edges. I imagine it would be possible to add a mechanism that would grab the drive at the business end and not release it unless the release button is depressed to compress the locking spring and retract the hold fasts. We can assume that unplugging one or both raid drives while in operation may result in data loss, even if the drives are hot swappable. Hot swapiness may not extend to drives unplugged while backing up your novel.  So any provision above and beyond gravity, such as bailing wire or duct tape to hold the drives in their sockets is an improvement in the common dock design.

My solution takes my own down home advice to heart, literally using baling wire to secure the drives. strappingThis solution is secure enough for an inverted mounting option, which was not too difficult to add to the dock base by way of four screws bothe removed and replaced and a file to make room for metal strapping across the bottom. Some technical skill with a power drill and a screwdriver is required to achieve this pinnacle in adaptation to the complex mounting environment under the fireplace mantle. Under the mantle is, of course, the most common place for your external raid when your server is also your home theatre PC in your fireside room.bailing

Bailing wire is much more dependable and longer lasting than either duct tape or cable ties and is way tougher than bubble gum, but lacks flavor. Don’t listen to those advocating twine, especially those composed of hemp. Bailing wire replaced twine in the iron age and no one cares to remember what things were like in the twine age when things needed binding. To minimize materials and the count of screws your bailing wire expert will need to bend and cut the wire with precision and accuracy in an attempt to maintain the appearance of symmetry and corresponding pride.asus dock dock mount