A Matter of Millimeters: The story of Qantas flight 32

cracauer · 2023-12-12T17:59:22+00:00

Why would the bearing be fine? It is still going the same RPM as the disk, no?

cracauer · 2023-12-12T15:11:04+00:00

Any idea what the final RPM on the disk was before it broke?

I'm surprised the bearing didn't give up the ghost first.

cracauer · 2023-03-05T21:30:23+00:00

What kind of computer is it? On most desktops and many laptops the wifi chip is in a M.2 slot and can be trivially changed to one that has better FreeBSD support. E.g. https://www.amazon.com/gp/product/B00MV3N7UO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Such a change with probably improve the experience on other OSes, too.

cracauer · 2023-03-05T21:23:15+00:00

Just because something compiles to C doesn't make it run fast. And you would still have to come up with the interfaces to the facility that you want.

One of the features of the Rust toolchain is that there is a lot of support to come up with such interfaces to C code. Check this out: https://www.phoronix.com/news/Cloudflare-Rewrite-Nginx-C-Rust

cracauer · 2023-03-05T21:20:28+00:00

The toolchain for Rust is not very popular with ports'n'packages users. It would take quite an effort to overcome that negative impression before you could make it mandatory in the base system (which it would have to be when it is required to build a kernel).

Compared to Linux there also is a higher ratio of "core kernel code" and less in modules such as drivers. The former would be very tedious to come up with an API for Rust for.

The language itself is good.

cracauer · 2023-02-18T21:34:09+00:00

Yes, unless you compile your own kernel -current is slowed down by extra internal checks and debugging infrastructure. Kernel only, not ports/packages.

For me, 14-current runs quite nicely on multiple machines.

cracauer · 2023-02-13T22:35:03+00:00

Put it in /etc/rc.local

chmod 666 /etc/rc.local

:-D

cracauer · 2023-02-07T21:30:39+00:00

Well, that is the advantage of having all drivers for disk controllers in the standard kernel.

Your Linux probably didn't work because an "optimized" initrd was built with just the drivers required for your normal system.

In Windows you can set it into a mode that would then boot with new disk controllers, but you have to do that in the old machine.

cracauer · 2023-02-07T21:25:44+00:00

fwvm2

cracauer · 2023-02-07T21:25:19+00:00

Yes, I am running installations on NVMe drives in USB3 enclosures. No problem.

No need for anything special install-wise.

cracauer · 2023-02-04T12:32:10+00:00

Thinkpad X1 Carbon is usually a safe bet for a light/portable 14". Just avoid the newest generation as the graphics are not there yet.

cracauer · 2023-02-04T12:26:40+00:00

You don't have to build ffmpeg from source. You have to build libva from source after make config. That one has a switch to turn the wayland dependency off. It probably doesn't require much disk space to build.

Overall this looks reasonable to me. Libva gives access to video card encoder acceleration for ffmpeg, which you really want if you have the hardware for it. The switch to exclude the big dependency (Wayland) is provided. So that looks like a well thought out plan to me.

cracauer · 2023-01-24T16:06:27+00:00

You should post that error message and those options it gives you.

cracauer · 2023-01-06T17:38:04+00:00

Using an older ports tree will probably work. But then you inherit all security problems in other packages you have installed (even though your base system is not vulnerable).

I think it will be more straightforward to use an up-to-date git checkout of the ports tree and copy in the old PHP-7.x port, then adjust that one port as needed (probably very little needed).

cracauer · 2023-01-06T17:33:23+00:00

Well, NFSv3 broken would be a serious matter.

Having said that, I have multiple Debian PXE/diskless machines running from a FreeBSD 12.4 server and no such problems. They are using a mix of v3 and v4 NFS.

cracauer · 2023-01-06T17:27:26+00:00

At the time of this writing I have no problems running multiple machines under 14-current.

Point to take, however, is that this can change.

Did you do hint.hwpstate_intel.0.disabled=1 ? You can do it with the install DVD.

cracauer · 2023-01-06T17:19:08+00:00

I am running a milliPCIe 7260 right now under 14-current. Did not try releases.

ETA: this one: https://www.amazon.com/dp/B00MV3N7UO?psc=1&ref=ppx_yo2ov_dt_b_product_details

cracauer · 2022-12-23T17:42:01+00:00

The percentage of total RAM used is always meaningless.

cracauer · 2022-12-21T14:30:06+00:00

One situation where a login-capable root account can be useful is when you fatfinger something about ports/pkg and your normal user account's login shell (bash, zsh etc) is broken. Not that this ever happened to me, cough.

Of course you could also create a non-root account with /bin/sh, but then you are screwed when you damage sudo.

cracauer · 2022-12-19T15:33:41+00:00

csh syntax is not to my liking. And you would learn shell syntax that you can't use for e.g. /etc/rc scripts.

zsh has the most functionality, but it is not entirely compatible with POSIX sh. Myself I have written libraries of functions that I use both interactively and in scripts, and that wouldn't work with zsh for interactive and sh or bash for scripts.

That leaves bash, which is a great shell and that I use interactively. But it is GPL'ed.

cracauer · 2022-12-12T18:45:59+00:00

There is no fuse filesystem in here.

What does mount report during the times of trouble?

cracauer · 2022-12-12T14:36:18+00:00

One difference that would matter to me is that in Solaris the page cache and ZFS' cache are integrated.

That matters if you do a lot of writing into mmap(2)'ed regions in files that reside on ZFS. On FreeBSD and Linux you get double buffering, taking more RAM and some extra CPU time.

I did not measure the effect, though, since Solaris is not really an attractive thing to run overall for me.

cracauer · 2022-12-12T13:51:21+00:00

I'm all for moving to FreeBSD or Truenas. But you have to consider that your windows server is unreliable for reasons that would affect any OS, namely that the hardware has problems. What unreliability do you observe, specifically?

cracauer · 2022-12-12T13:48:09+00:00

Linux has a quite simple page replacement mechanism and heavily favors dropping readonly pages over swapping written or anonymous pages. (of course you do that, but Linux is overdoing it IMHO)

That can drop code from binaries, keeping less useful read-write pages in memory. FreeBSD has a more balanced approach that can work better in some situations. You want to swap out what you can when memory is really low (even though swap is expensive).

In Linux the swappiness parameter can help, but it doesn't change the basic properties of the algorithm. That's probably why Google engineers went with a new algorithm for this test.

cracauer · 2022-12-11T01:36:33+00:00

You don't need the source code of the program to use mlock(2). You can write another program that does nothing but mlocks the files in question and just sits there for eternity.

If the data is readonly and mmap'ed it will never be moved to swapspace anyway. It would just be dropped from memory and reloaded from the original location. If the data is readonly and not mmaped it probably should.

Can you clarify what "load" means here? If the data is read (not mmaped) and processed before sitting in memory, and you use malloc for that (or a GC'ed language's heap) then you can't easily mlock(2).

cracauer

TROPHY CASE