Posts by Dazed and Confused

Re: Still a problem though

Darwin awards await the impatient.

Re: Still a problem though

One of our local petrol stations is just about next door to the switching station where the 11KV lines come it. As you say, qualified people might be allowed to hook your car up to an 11KV feed.

Re: "Critics have been understandably sceptical"

> Those critics are Nobel Prize winners ?

Sure you can disagree with a Nobel Prize winner. If you can prove that you're right they'll probably give you a Nobel prize for your efforts too. That's how science works, I imagine that the good Dr Goodenough will happily pin the prize on your chest. Then take what you've achieved and run with it and maybe give the world an even better battery.

On the other hand, it's more likely that the sceptics have some vested interest in the current tech.

Re: PDP Disk drive numbering

VAXes too.

It was a great scheme. It meant when you came in on a Monday morning find your terminal was dead you could wonder into the computer room, notice the red light on the first drive and the pile of paper at the back of the console teletype. Power off the Vax.

And then for the good bit, you pulled the little plastic drive number light off the first drive, slotted it into the second drive and boot up to single user mode. Back the he root FS was small enough to keep a copy on all the drives so it was easy to get the machine up far enough to start reading the backup tapes.

Re: What about Britain?

I wasn't aware that the IEC was an EU body. Barmy Boris might not ban it if he knows it never came from Brussels.

Re: Apple's fault

They made $24b on cables

Is this because their £20 cables are perhaps the only thing on the planet with a lower SLA than a Galileo positioning satellite system?

My youngest used to have an iPod with one of those plugs and used to go through several cables a year. All the parents I knew who's kids had iAnythings said the same. If you went to the iStore and looked at the customer feedback on the cables there were thousand and thousands of 1 star ratings and bugger all else. Maybe they've made them last longer now, he stopped using the iPod so it stopped being my problem. But I did find that the cheap knock off cables on Amazon or eBay were massively more reliable. Perhaps people take more notice of the star ratings on those sites than on Apples own site.

Re: WTF?

It stops then?

What do you do, take the phone of the hook?

In my experience the phone still rings for ages after the problems fixed.

Re: Incredible

> 42 year-old hardware, absolutely no way to perform a service, and Voyager 2 is *still* running!

That's coz it's not running W10

Re: Military Spec

I believe that a lot of the difference you've seen is down to the shift from doing the support inhouse

It wasn't just things like support. Back at the start of the 90s I was doing a lot with Unix workstations. HP's new 700 series was popular with the military. I tried taking one to bits once only to find that under the top plastic case was a sheet of metal thick enough to be held down with a huge number of countersunk screws. I asked someone why? Mil-Spec, if it looks like it's the right height for someone to stand on, they need to be able to cope with someone standing on them - In boots.

Re: Is there a way to bet that:

Followed by Jupiter

Just Un Plug It Till Everything Resets

Re: I know I'm weird

I know I'm weird ... But I just took a quick mental inventory and I'm sure that I don't own a single device that has a USB-C port

Is not being the sort of person who must have the very latest model of phone the moment they're released now classified as weird? If so I'm also guilty as charged :-)

Not seen a new feature on a mobile that would make me want to change for years. It's get changed when it breaks. I guess the new one will have the new connector.

Re: "It solves a problem that people have."

Sorry, you're wrong.

The problems at RHEL6 are totally different. The problem I described above is what happens at RHEL7. Go try it.

If you look at the comments I made above you'll notice that I was talking about how NM & systemd interact, does that sound like I was in "6" mode?

Re: "It solves a problem that people have."

One reason for hating NetworkManager is that it breaks things. When you run NM it tries to react to changes in your networking environment, this is its job. So when you create a new networked device NM wants to react. Some of these reactions can be good. So in the case I mentioned above you reload the NIC driver and NM restarts the networking on the NIC, which is nice.

But it can also do things like restart other bits of SW, for example the DHCP server. So you create a VM, it gets a vnet device for each vNIC and NM restarts the DHCP server for each of these new vnet devices. If your VM has several vNICs or you manipulate a bunch of VMs together you get a storm of network device changes and therefore a storm of restarts. At this point systemd and NM get into a punch up which results in systemd disabling the services that NM is causing to restart. As a user what you see is that when you start some VMs other random bits of SW stop running. I'm guessing this is why step one of the OpenStack installation guide say disable NM (OK I've not checked this for a a year or so, but it did the last time I checked).

NM can be great on laptops.

But I use CentOS/RHEL as a server OS and that tends to mean you use it in different ways. On a server I'm not sure of where I might want to separate a connection and a device, whereas on a laptop it is useful to be able to switch between wired and WiFi networks.

To my mind there are too many things in 7 which seem to be aimed at the destop/laptop world which are detrimental to the server world. YMMV.

But udev has been subsumed into the systemd project. It ain't part of PID 1, but they've done things to udev so that some things which worked fine in previous version no longer work in systemd-udevd.

One of the things that I don't like about systemd is that lots of things which have nothing to do with PID1 or even the general idea of an all purpose service manager have ended up inside the systemd world, udev being one such thing.

Re: Why do we need unit files? Parallel startup tasks.

OK, so one possible example.

In traditional Unix/Linux you list all the filesystems you want mounted at boot time in the /etc/fstab file. At some point in amongst the startup scripts someone runs a mount -a or a mountall and all your filesystems get mounted. What happens if one isn't there yet?

In the systemd view of the world early on something reads the fstab file and generates a set of mount units with a dependency on device units. When the devices are found udev processes them, in the systemd world a flag tells systemd-udevd to make a device unit associated with the device. When both the mount unit and the device unit are there the dependency is met and the filesystem gets mounted. This allows for a certain degree of asynchronous mounting if the storage devices are starting at the same time that the servers are starting.

Now, there's some dumb stuff with this, like needing to kick systemd to get it realise that the fstab file has changed.

There are lots of things I don't like about systemd. Like you I don't see the need start a lot of the services at boot time in parallel. I don't like its spreading its tentacles in every direction. But I've come to quite like the idea of having one central manager for all sorts of different services. But please for the love of all we hold precious can we not have PID 1 having such a large attack surface.

Re: Device naming

I don't think the device naming weirdness is down to systemd, that's down to the kernel initializing stuff in parallel. So if you've got multiple disk interfaces they're being enumerated at the same time, so it's anyone's guess which device will be sdWhatEver. You could see issues in pre-systemd boxes too, Linux doesn't natively have persistent device naming, hence the pre-systemd udev rules to make /dev/disk/* and the similar arrangement for tapes etc.

I must admit I've not tried changing the names of disks with systemd-udevd just used symlinks. If multiple udev rules generate the same symlink then the one which remains at the end is the last rule to fire, so you'll see this for multipathed disks is if you compare /dev/disk/by-id and /dev/disk/by-path, and RHEL7's (with systemd) and RHEL6 (without) behave the same here.

BTW, I'm not trying to defend systemd here, I've got enough gripes against it.

Re: "It solves a problem that people have."

> One thing I can think of that systemd does that sysv didn't is "status management"

Well, when it works it does, but :-)

So if you hate NetworkManager and want to continue to use the network service and ifup/ifdown you can disable the dreaded NM and enable network. Great. Then if a NIC goes down on you or someone does something like reloaded the NIC driver to tweak a load time param the network goes down and systemd won't bring it back up again. You can't do a systemctl start, it won't do a proper stop or a restart. You have to go in and manually cleanup before you can restart it.

Oh and of course the systemd team have subsumed udev, but they've imposed their "my way or the highway" approach so you can't just have udev do the ifdown & ifup for you as they take longer that the systemd-udev allows anything run from an action to take and even if drop them into their own process group and session it tracks them down and does a kill -9 without bothering to log anything.

I think there are some great ideas in systemd, I really do. But there is a less than stellar implementation at times.

I remember listening to the BBC series when I was young, the transistor radio hidden under the pillow I must have been 10 or 11. It had be totally hooked. A few years later I found my sister's boyfriend had the series on open real tape and I copied it. Later on they published it on cassette tape, I've still got the set somewhere. But you can now get it from various places, I've got it from Audible along with an unabridged rendition. The first two books are very close to the original, the radio adaptation of Second Foundation is much further from the original but I think I actually prefer it but that might just be because I heard that first and I'm more familiar with it.

Re: First aerial food delivery?

Before the Berlin Airlift there was Manna

https://en.wikipedia.org/wiki/Operations_Manna_and_Chowhound

and I've sure there must have been earlier deliveries too.