HorstG

This is exactly what overprovisioning is: The sum of possible future allocations is greater than available space.

Yes. RAIDz (without the "1") was the original RAID5-equivalent, RAIDz2 is equivalent to RAID6. However since nobody really knows what the hell z1 and z2 is and z1 is easy to mix up with RAID1 for nonZFS people, calling it z5 and z6 is far less confusing.

ZFS does overprovision all filesystems in a zpool by default. Create 10 new filesystems and 'df' will now display 10x the space of the parent fs. A full fs is handled differently than your volume manager running out of blocks. But the normal case is overprovisioning.

And after donating credentials, the donor and IT are better off just claiming the password was "phished" (winkwink) when caught.

Why? What is bad about playing around with leftover hardware?

Performance wasn't robust, especially on dead disks and rebuilds, but also on pools with many (>100) filesystems or snapshots. Performance would often degrade heavily and unpredictably on such occasions. We didn't loose data more often than with other systems.

"play" comes from my distinct impression that the most vocal ZFS proponents are hobbyists and admins herding their pet servers (as opposed to cattle). ZFS comes at low/no cost nowadays and is easy to use, therefore ideal in this world.

I think the optimal number of RAIDz5 disks is 3, if you just want performance. But this wastes lots of space of course. Also, the number of SAS/SATA-channels per controller and the topology of expanders is important. Thats why I don't think there is a recipy, you have to try it out for each new kind of hardware.

And as another thread pointed out, stripe size is also an important parameter.

Education might not be the same as research in this license's terms. And there are even software vendors picking nits about writing a thesis being either research or education, depending on their mood and purse fill level...

"Proven" is a maybe impossible standard: Kernel devs hint at the GPLonly exports having been useful in certain cases they prefer not to discuss on a ML. https://lore.kernel.org/lkml/20190110131132.GC20217@kroah.co...

One can interpret this as something legally significant, or an embarrassing private anecdote, or nothing substantial at all, maybe even just talk. However, I'd give them the benefit of the doubt. Not the least since they could be the ones against Oracle's legal dept...

Some features such as Raid5 were still firmly in "don't use if you value your data" territory last I looked. So it is important to be informed as to what can be used and what might be more dangerous with btrfs

Rust and Go both can have C-based libs linked to their address space thus exposing them to the same problems ASLR diminishes (I accidentially wrote "solves" here. ASLR solves nothing, it just makes exploits harder. It's a holey raincoat...). Also, both language runtimes and compilers might have flaws. "don't need" is dangerous hybris imho, of the same kind that was the downfall of Java security. Lots of Java exploits were actually just broken linked versions of libjpeg and others.

No single measure will ever be sufficient, one should never become complacent like that...

Alcohol cools by widening the blood vessels in your skin and extremities. This makes you feel warmer, yet it lowers your overall average and core temperature. This is what makes alcohol in cold weather so dangerous: it really helps your cold fingers and makes you feel better, while actually making you worse off by wasting heat.

Stripe size could have been a problem, though we just went with the default there afair. Most of the first tries was just along the Sun docs, we later only changed things until performance was sufficient. Dedupe wasn't even implemented back then.

Maybe you also don't see as massive an impact because your hardware is a lot faster. X4200s were predominantly meant to be cheap, not fast. No cache, insufficient RAM, slow controllers, etc.

Actually, this matters a lot in many enterprises. Beancounters hate excess capacities, so there are never enough spares and everything is always almost full.

Maybe SV is different...

Most non-hobbyist RAID hardware does online-scrub just fine (not that I would recommend wasting money on such hw).

Btw, ZFS scrub is not only a RAID-block-check but also a partial fsck, so its not really comparable.

Group your disks in bunches of 4 or 5 per Raidz, no more. And have them on the same controller or SAS-expander per bunch. Use striping over the bunches. Don't use hotspares, for performance maybe avoid RAIDz6. Try out and benchmark a lot. Get more RAM, lots more RAM.

We had a bunch of Thumpers (SunFire X4200) with 48 disks at work, running ZFS on Solaris. It was dog slow and awful, tuning performance was complicated and took ages. One had to use just the right disks in just the right order in RaidZs with striping over them. Swap in a hotspare: things slow to a crawl (i.e. not even Gbit/s).

After EoL a colleague installed Linux with dmraid, LVM and xfs on the same hardware: much faster, more robust. Sorry, don't have numbers around anymore, stuff has been trashed since.

Oh, and btw., snapshots and larger numbers of filesystems (which Sun recommended instead of the missing Quota support) also slow things down to a crawl. ZFS is nice on paper and maybe nice to play with. Definitely simpler to use than anything else. But performance-wise it sucked big time, at least on Solaris.

Hardware tooling is bad. Like really lifesuckingly bad. Download yourself some free Xilinx IDE and try to do some Verilog Hello World on a cheap demo board. Blink a LED or something. Its so bad you will want to scream: Dog slow sythesis (~compilation), useless IDE support, ten steps to run something, badly composed. Errors will land in some arbitrarily named logfile somewhere between the code. More expensive tools are hardly any better.

I started doing hardware but ran away, I feel it is a waste of developer time to even consider doing any custom hardware designs. People should be punished for even thinking about using FPGAs. Just don't do it.

Sorry for the rant, but I feel warning yall is my duty ;)

Yes, making the bombs themselves seems to be easy. The difficulty comes from U232-contamination which decays into strong gamma emitters, making handling difficult. However, there seem to be paths for the production of pure U233 from chemically separated Pa233, which one might be doing anyways in a thorium reactor. That would mean a significantly higher proliferation risk, because one would get pure bomb fuel form the normal operations of the reactor. However, I don't know enough about how easy or likely that would be to judge.

But in all, you are right, I think. And maybe even more than right.

They are not wrong, but also not right in all scenarios. Truth very much depends on the reactor design. Thorium is often associated with Gen4 reactors which are responsible for the claims of superior safety. Not much, but some of the safety benefit comes from thorium. Similar for the claim of less waste: Some reactors have better neutron economy, burning their own waste down to more shortlived and therefore "better" isotopes. Or, by the same mechanism, can utilize existing waste as fuel. Also, continuous loading and separation of isotopes only works well with liquid fuels which is a Gen4 idea.

Thorium is more of a side-topic there.

On the economic side of whether thorium is cheaper, the submission argues in a very underhanded manner. Yes, fuel is cheap compared to building the plant in all cases. But the fuel cost of thorium is an order of magnitude below uranium due to no enrichment (for light water reactors in the fuel, for heavy water reactors of the water). And possibly (for liquid core reactors) the unnecessary fuel elements production.

It is useless to make claims about a particular fuel without looking at a concrete reactor design. Leftover isotopes for example are very dependent on neutron flux and neutron energy as well as general breeding properties of the reactor. This in turn decides the waste to be dealt with, proliferation risk and possible reuse of leftover fuels from previous generation reactors (which the submission didn't even discuss).

Also, the answers lack nuance. E.g. proliferation risk is present through U233, however, U233 seems very difficult to deal with in bombmaking. So at least it's less of a problem maybe.

There is such a system in Germany, called Grüner Punkt or Duales System. They tax manufacturers' packaging and run the collection and recycling from that tax income.

Imho it didn't help all that much. I did not find numbers for the reduction in packaging, but my impresssion is "none". As for recycling the waste they collect, there are numbers between "half is just icinerated" and "only 5% is recycled": https://de.m.wikipedia.org/wiki/Duales_System_(Abfallwirtsch...

Upgrading Windows7 to Windows 10 usually needs a hardware upgrade. And installing windows and office and decrappifying it takes ages.

Rather replace with your favourite Linux, no hardware upgrade necessary, LibreOffice is included, Spyware, Phone-Home-Functions and other crap missing by default. Saves lots of time.

But the outcome would probably just be a law exempting politicians from the location tracking.

Yes. Namespace support has been a great source of CVEs, and disabling all kinds of unneeded namespace functionalities is one of the first steps when hardening a Linux kernel.

afaik (second hand) CO2 is used for safety reasons, humans can sense a CO2 poisoning but not an excess of nitrogen.

We do. But the bureacracy responsible for enforcement is toothless, understaffed, intransparent and sometimes maybe even corrupt: https://de.m.wikipedia.org/wiki/Bayern-Ei-Skandal

https://m.faz.net/aktuell/rhein-main/wursthersteller-wilke-h...

Another possibly related factor in univerity cafeterias: The kitchen personell are public employees, underpaid but unfireable. As our cafeterias head chef told me, this causes them to not caring one tiny shred about anything. The chef can't discipline or fire them, first because of the protections as public employees and second because he can't find replacements. Therefore, even simple stuff like properly cooking noodles, checking if the chicken is done or basic hygiene is a challenge...

With the obvious consequences. My suggestion for cafeteria food is: Avoid anything that could be harmful if prepared improperly, because it will be.

The Cybertruck can't be brutalist because it us not ugly enough... At least it is far less ugly than anything properly called brutalist.

Its rather nice, comparable (but not as good) as e.g. the Lamborghini Countach and similar designs.

From the employee side, there should not be an extra cost to pay. The problem is with companies and bosses wanting people to come to the office. That is what needs to be fixed, therefore the company needs to be taxed, not the employee. Taxing the employee just makes shitty underpaid jobs even worse, no upside and maybe increased unemployment as a downside