500G in a 24h period sounds like it will be highly compressible data
It sounds like audio and video to me which is not very compressible at all if you need to maintain audio and video quality. And good luck booting a system with that many drives in "under 30 seconds" especially on a ZFS system which needs a lot of RAM (assuming you are following industry standards of 1GB RAM per 1TB of data you are hosting) as you will never make it through RAM integrity testing during POST in under 30 seconds.
1) The cold plug is not the issue, rather, the server itself needs to be booted and halted on demand (don't ask, long story).
You will never find enterprise grade hardware which will do this. You will be even harder pressed to do this on mechanical drives (for the OS) and even harder still with random new drives being attached which may need to have integrity scans performed. This requirement alone is asinine and against every rule for data center and system administration handbook for something that is serving data to other machines. If you need something that you need to halt and shutdown so you can load the drives, well, you do that on something else other than the box which is servicing the data requests to other computers, and you copy the data from that one system to the real server.
2) Because it's better? Do I really need to justify not using windows for a server on Slashdot?
No you don't need to justify it, but you do need to explain it some. For the most part it sounds like most people where you work do not have much experience with *nix systems, because if you did, you would never have had requirement (1) in the first place (as you would know the whole point of *nix is to be able to separate everything so that you don't have to bring down the system just to update/replace/remove one particular service/application/hardware, everything is compartmentalized and isolated, which means the only time you should ever need to bring down the system is due to catastrophic hardware failure or you needed to update the actual kernel, otherwise everything else should be build such a way that is is hot-swappable, redundant, and/or interchangeable on the fly).
3) The shares need to be easily accessible to mac/win workstations. AFAIK samba is the most cross-platform here, but if people have a better idea I'm all ears.
Well, SAMBA is the only thing out there that will share to Win/Mac clients from *nix, so that is the right solution.
- Take a server that is off, and boot it remotely (via ethernet magic packet)
- Have that server mount its drives in a union fashion, merging the nearly-identical directory structure across all the drives.
- Share out the unioned virtual tree in such a way that it it's easily accessible to mac/win clients
- Do all this in under 30 seconds
I don't know why people keep focusing on the "under 30 seconds" part, it's not that hard to get linux to do this.....
They are focusing on the "under 30 seconds" part because they know that it is an absurd requirement for dealing with multiple hard drives which may or may not have a working filesystem as they have not only traveled/been shipped, but have also been out in the actual field. The probability of data corruption is so astronomically higher that they know that the "under 30 seconds" is idiotic at best.
For instance, I can't even get to the BIOS in 30 seconds on anything that I have at my work. Our data storage servers take about 15-20 minutes to boot. Our compute servers take about 5-8 minutes. They spend more that 30 seconds just performing simple memory tests at POST, let alone hard drive identification and filesystem integrity checks or actually booting. This is why people are hung up on the "under 30 seconds".
If you had a specialty build system, in which you disabled all memory checks (REALLY BAD IDEA on a server though since if your memory is bad you can corrupt your storage because writes to your storage are typically from memory), used SSDs for your OS drives, had no hardware raid controllers on the system, used SAS controllers which do not have firmware integrity checks, you might, just might be able to boot the system in 30 seconds. But I sure as hell would not trust it for any kind of important data because you had to disable all the hardware tests which means you have no idea if there are hardware problems which are corrupting your data.
Truth is, imperial is actually simpler for household things like baking and cooking, because you're usually working in single digit numbers rather than triple digit numbers, which is great for the mathematically impaired.
Really? Many people seem to struggle with fractions.
There's no reason cooking using metric couldn't use fractions -- half-kilo, quarter-kilo, eight-kilo etc -- yet it doesn't. The fractions make it more complicated to scale recipes.
That is the whole point of imperial units, 1 gallon = 4 quarts, 1 quart = 2 pints, 1 pint = 2 cups, 1 cup = 16 tablespoons, 1 tablespoon = 3 teaspoons.... You don't need to use fractions, you simply use the smaller unit. Yes, for some things it is easier to use a fraction (cups is the one that comes to mind most often, but that is taken care of with a "measuring cup" anyway which has lines for 1/4, 1/3, 1/2, 2/3, 3/4). This way, people don't use have fractions or decimal places in their cooking receipts, because as said, too many people struggle with understanding them.
Fahrenheit also makes sense for temperature because of how much of a temperature difference we can feel, which is why a lot of metric thermostats go up in increments of
They don't (or if they do, I bet the Fahrenheit scale goes up in 0.5 too), and most systems aren't that accurate anyway (the heat/cooling doesn't kick in again if the temperature has fallen/risen by only 0.5C).
Typically not. The only place that uses tenths or hundredths of a degree in Fahrenheit is for measuring a person's temperature to find if they are above normal temperature (and have an infection/illness/etc.). Pretty much everything else is simply in whole digits of Fahrenheit because as said, the difference in 1 degree in Fahrenheit is about what a human can physically detect and tell the difference in. Any less than a full degree and you have a hard time distinguishing it, which makes it work perfectly well for just about any situation, cooking, outside temperature, and inside temperature settings for heating/cooling systems. But for Celsius, you must use increments of
Mathematicians stand on each other's shoulders. -- Gauss