Nate and Charles -- This is a fascinating and educational thread. Lots of interesting and useful info from people with plenty of experience. Thanks for sharing with the rest of us.
Jim - K6JM ----- Original Message ----- From: Charles Scott To: dstar_digital@yahoogroups.com Sent: Monday, September 06, 2010 6:04 AM Subject: Re: [DSTAR_DIGITAL] Gateway / NI-Star System Requirements Nate: Yep, since the system only had 2 drives I have it set for redundancy rather than space (it has an integrated RAID controller). It can therefore loose a drive and continue to run without the software knowing what happened (although I will). The better way to do it would be to throw in 6 drives so I could have a couple fail, which is what we do with our servers. Found one on E-Bay with 6 32G drives the other day for $99 and it still had dual supplies and everything. These are a great value but way to noisy to run in my shack! They do, however make great Web servers with 4 cores (2 processors) 6 drives, and a bunch of memory and I can get those configurations for about 1/10 the cost of current production systems. Yes again, since the system has "integrated lights out management" that uses a separate (third) Ethernet connector, you can connect to it even when the system is off or is otherwise not responding and turn it on, reboot it, or look for problems. That seems to be perfect for difficult to reach repeater sites. As to SSD and such, my preference would be to spend less than the cost of one SSD and get multiple complete systems like these DL385's. Could then either run them in some full redundancy configuration or simply leave one off till the primary fails then turn it on remotely. Could bring the spare up periodically to update it if necessary and never go to the site. The only thing left to do would be dual Broadband feeds and redundant switches, but that seems like overkill for Ham stuff. The problem I see with all this is that these kinds of "deal" systems will become popular for this type of application and I won't be able to get them cheap anymore. So everyone please ignore this thread! Chuck - N8DNX On 9/6/2010 5:12 AM, Nate Duehr wrote: > Think about doing RAID1 and having two disks in it if it's inaccessible for 1/2 of the year. > > Disclaimer: I did this with W0CDS, which lives on top of a very high mountain -- and it still bit me in the hindquarters. Linux Software RAID1 isn't 100% ready-for-prime-time, sadly, after all of these years. > > The machine lost a drive, and instead of just chugging along, it started throwing I/O errors for all commands. > > Luckily, the RAID was working, it just never "detected" the failed disk. A power off/power on reboot cleared that problem and it came right back online with a single disk and one in a failed state in /proc/mdstat -- so that leads to item #2... > > Get a way to remotely REBOOT your system... be it a transistor switch on a co-located analog repeater controller, a remote power on/off device like a managed power strip, whatever works that you trust and can access when the box is down. > > That would have saved someone a trip to the mountain. > > But he went, we proved the machine would run on one dead drive and one live drive, and then he yanked the dead one to bring it down to get a replacement. > > Which leads to item #3... > > Since Linux Software RAID can work with, but really really really likes drives of the exact same CHS layout and size... get a couple of spares. Drive technology is still changing so fast, that by the time you need it, that model will be hard to find. Drives are cheap, keep spares if you're using RAID, or be prepared to backup/rebuild the system from scratch with two new drives when one finally fails. > > The reason for the drive failure we suspect is two-fold... high altitude (heat, less air between the spinning disk and the "flying" head, etc) and really bad power up there. Lightning wreaks havok with everything up there every summer, and apparently this drive died too soon into its usual life-span because of all the power hits. Even once we had a UPS inline, the "stuff' that comes in on the power lines up there is just utter trash all summer long. > > It's just a tough environment for PCs. If you're building from scratch and don't mind the eventual performance hit and need to do a "secure wipe" and reload once in a while, the modern Solid State Drives are a good choice for a difficult site, I think. But their internal fragmentation problems and limits are becoming well-documented, and that "secure wipe" to get them to go rewrite every bit of the flash and reset the controller that's managing the flash, is important for most brands. Some good reviews of cheap vs. "server grade" SSDs are starting to show up on the web in droves now, whereas for a few years there, the testing and performance numbers just weren't available. > > I'd say it's a toss-up between spinning platter and SSD, when you factor in price. Cheaper than owning two SSD's is owning four mid-sized spinning platter technology drives, so you'll have to decide if you want to pay the premium and be an early-adopter, so to speak. > > -- > Nate Duehr > n...@natetech.com >
