I have a new (Sept 2011) ReadyNas Duo. The hookup and config went exactly according to instructions, with some much appreciated help from this forum. I went with the more expensive Hitachi UltraStar HUA722020ALA330 drives with 5 year warranty, we use them in the big SAN at work and they have a high level of reliability (rated at 1,200,000 hours MTBF, that’s about 130 years). Thus far, no hardware issues on the drives or Duo (sort of). Other factors – I do not have jumbo frames enabled, and my router is an older LinkSys WRT54GS with current but stock firmware.
I quckly came up against some problems that are also covered in the forum. Dragging and dropping files or folders from one Duo folder to another takes a very long time. This is because the data is being copied from the NAS to the PC, then down to the NAS again. If you do this over a wireless link, expect a long wait and poor performance. The best solution to this is to load SHH and connect directly to the NAS. Be ready to learn a little Linux (modified Debian), mine is a little rusty but I’m coming up to speed. As well, I have had issues with the system hanging on large file transfers from a PC host to the NAS. I even broke out the Command Prompt and used xcopy, but had the same problem – in fact, it failed with a Windows error “Insufficient Memory”. Interestingly, when I use the Linux cp command to copy to or from a NAS-mounted USB hard drive, it seems to work fine. More on this later.
The Hitachi drives run pretty warm, over 43c, and while they are rated at up to 60 I’d like that to lower that. I figured I’d put in a higher CFM fan; unlike some on the forum, my NAS is in a home computer office, so noise is not an issue. I got onto NewEgg and ordered a 60mm Sunon PMD1206PMB1-A fan (52.5 CFM) and a 1GB Crucial CT12864X335 DIMM. We run Crucial memory in the big iron VMWare servers in the data center at work, so surely to gawd they should work in my teeny Duo.
They arrived. I cracked the case and installed the fan first. It’s too thick to fit on the inside of the case, so I just flipped it and installed it on the outside. The cable fit nicely through a little punchout about one centimeter about the power supply connector. The plastic connecter had wire colours matching the original and fit right into place. However, the fan blades only moved a bit when the unit powered on, then didn’t spin at all. I notice the original Crown AGE06025_12U fan is .21A and the new Sunon is 12W (or .83A at 12V), so perhaps the NAS power supply does not have enough oomph to supply the new fan. I’ve now put an 80mm fan with a closer power rating with a fan adapter on the outside, the drive temp has dropped to 40C; I’s have liked lower but I’ll take it. I recommend that if you upgrade the fan, pay attention to the amperage. Also, be prepared to modify the side panel fit slightly to get it reseated around the adapter.
I then loaded the new Crucial DIMM (the 8 chip per side configuration). This was quite simple; when facing the rear of the unit, remove the two small black screws holding on the right panel. Put your hand flat on the panel, and slide it backwards a bit, then lift it off. Gently pull back the plastic clip on each side of the old DIMM, pull it up and out at an angle (save it!). The new memory was keyed to fit the socket, push gently in and down and it snapped right into place. I ran the memory test ten times successfully, taking about 90 minutes per run. Powered back on and after a file system check, everything looked good. The Duo ran noticeably faster after the upgrade, much faster in pulling up and switching menus, faster building screen views with graphic icons, and seemed faster transferring files. It ran fine, but after I tried a few file transfers it started hanging unexpectedly and one day later the dreaded catch-all “path too deep” error came up, and nothing worked right after that. The Duo finally hung hard, unable to see it in RAIDar or power it down logically, had to pull the power and reverted back to the original memory. I had a lot of trouble bringing the unit back online, and finally had to pull drive 2 and use the paper-clip reset to revert to factory defaults before reinserting second drive and re-syncing. Very unpleasant.
From my experience and from what I have read on this forum, it seems clear that the reason the memory HCL has been removed is that there are no upgrade DIMMs that will *reliably* upgrade the Duo. Given statements on the NetGear website that additional memory can improve performance by up to 12%, and my own thinking that it could improve large file transfers, it is clearly a worthwhile upgrade and I’d like to see NetGear address it by selling validated RAM (come on guys – revenue!). Until this is resolved, I do not recommend that anyone reading this risk their money buying a memory upgrade from any third party manufacturer.
So, back to the large file copy problem. Using both an XP SP3 and a Win7 PC, I am able to repeatedly cause a directory copy with individual files in excess of 300MB to fail. The same problem occurs when using Command Prompt or when I am SSHed into the NAS. I wonder if it is related to the seemingly meager 256MB supplied memory running out of cacheable space. Another option might be the router overflowing its buffer space, except the Linksys WRT54GS v6.0 has only 16MB RAM, so I’d expect it to hiccup at much smaller file sizes if that was the problem. I can still copy the entire file system, large files and all, to and from a direct attached USB hard drive – it takes over 30 hours, but no errors.
Next steps might be to direct connect the NAS to the PC and bypass the LAN. I’d be happy to hear any other ideas from the forum’s collective brain. I do like the Duo a lot, and am learning to live with its benefits and limitations.
I have done much larger directory copies with my unmodified Duo without seeing the copy failures you are seeing - the largest share being about a terrabyte. The copies were done on wired gigabit ethernet connections, usually using robocopy. Some went NAS to NAS, most were between the NAS and the PC.
I suspect your bulk copy problem is network related - have you checked the duo network stats?
StephenB, thank you for that info. I'm curious, when you went NAS to PC, did you have a switch in the mix? What type? I have checked the network stats and there are no errors evident, but your experience gives me some useful ideas to attack the large file transfer issue. I know others have had the same problem, I'd be interested in hearing any of their troubleshooting experiences. BTW, I have checked cables and drivers.
I'm in the same boat as mmbds32 except I have 2 bays still unused in my QNap 409. When I bought the NAS it stated that up to 1 TB drives can be used. That is as big a drive as was readily available at the time. Can the larger size drives be used? Does it make more sense to add bigger drives or use all 4 bays?
StephenB, thank you for that info. I'm curious, when you went NAS to PC, did you have a switch in the mix? What type? I have checked the network stats and there are no errors evident, but your experience gives me some useful ideas to attack the large file transfer issue. I know others have had the same problem, I'd be interested in hearing any of their troubleshooting experiences. BTW, I have checked cables and drivers.
I am presently using a Netgear GS724Tv3 (bought a few months ago). Before then I used a small unmanaged DLINK switch; I don't recall the model. Jumbo frames are off everywhere. 802.3x flow control is turned on (and I believe it was also on by default in the Dlink). That might be worth looking into, though it seems to me that if flow control is needed, it would be when the PC is writing to the NAS (unless the PC is running 100 mbit ethernet or wireless). My switch stats do show pause frames being sent and received on the Duo switchport.
BTW, I also have done large (terabytes) transfers between my Pro and the Duo (the Duo is presently a backup NAS) using NFS. And multiple gigabytes with rsync.
I've rolled back my Duo to software rev 4.1.7, and the problem is gone. When 4.1.9T2 goes GA (Generally Available), I'll give that a shot. It it certainly faster now than it was with 4.1.8.
