* Posts by Bronek Kozicki

1286 posts • joined 6 Sep 2007

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Boeing 787 software bug can shut down planes' generators IN FLIGHT

Bronek Kozicki
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Unhappy

I would be more concerned about climate control than anything else. Aircraft spends most of the time on high altitude, where as a glider it would give pilots lots of time to recover, but with air pressure falling fast they might not be able to do much after short time.

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What is Apple's idiot tax on Watch these days? 'About $265 or 80%'

Bronek Kozicki
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Devil

"if sales match the interest the Apple Watch has generated"

... does he mean that if all the journalists who slavishly follow the trend to write about, show and pontificate this one product, had actually bought one, then Apple would be much richer than it is now?

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High-speed powerline: Home connectivity without the cables

Bronek Kozicki
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Re: Solwise

Just few days ago I received pre-ordered TP-Link TL-PA8010P

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Debian ships new 'Jessie' release with systemd AND sysvinit

Bronek Kozicki
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Re: systemd a copy of Solaris SMF

@MadMike thanks for that, but I think you will agree the problem is not as much with an OS but with system (hardware) architecture and applications which run on it? Basically there are limits when you can have cache coherency between all sockets and still expect sensible performance from traditional many-synchronized-threads-paradigm applications, and beyond that you have to make a move to network (real or virtual) or message passing interfaces such as OpenMP.

I do not quite see where is place for Linux in this discussion, to me it seems to be about discord between application(s) and hardware architecture limitations. Linux might (or might not) be a host hypervisor, guest VM or even entirely left out of picture - which would improve nothing.

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Bronek Kozicki
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Re: systemd a copy of Solaris SMF

"Nobody uses Linux on large 16/32 socket servers"

I think you are mistaken

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Bronek Kozicki
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Re: How to get rid of systemd and ban it

FIFY

How to remove systemd from a Debian jessie/sid installation

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2016 might just be the year of Linux on the (virtual) desktop

Bronek Kozicki
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Re: Why?!?

I don't know where "somewhere else" came from, as I understand both XenApp and XenDesktop are applicable for both "on premises" and "in the cloud" deployments, and actually the former one is more traditional model of doing VDIs. You do not outsource from your firm, you outsource from individual desks to your data centre.

Although what do I know, I am mere developer.

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Bronek Kozicki
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Re: Why?!?

You are unnecessarily focused on "renting" part, the customers already paid for Citrix linceses and are presumably using these for Windows VDIs. If they also have users who need/prefer Linux desktops and do not want/cannot spend the time maintaning their own desktops, these machines can be now put on the same VDI and managed using familiar tools by corporate infrastructure team. This VDI is what Citrix is selling, and the actual machine OS is just an extra "flavour" to choose from. IMO adding Linux to the mix is a good thing.

The point is: do not confuse corporate deployments where you have hundreds of end-user machines per one person from infrastructure team (who are also maintaining network, phones, AV etc.), with your home where you can spend as much time as needed to keep much smaller number of machines (below 10, most likely) in good order.

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C++ Daddy Bjarne Stroustrup outlines directions for v17

Bronek Kozicki
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Trollface

Re: Will anyone really understand the language?

"learning the language is even more difficult. It is a never ending task."

Good, that's how it should be.

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Windows 10 Device Guard: Microsoft's effort to keep malware off PCs

Bronek Kozicki
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Re: This is opening a wriggly can of worms

It is a can of worms, but I think probably not as bad. A fresh fish bait (rather than something old and mouldy), I'd say.

1) agreed, although virtualisation overhead in modern CPUs is really small, especially if hypervisor does not over-commit memory, CPUs etc.

2) and 4) agreed again, however I suspect this would be only enabled on certified machines with correct ACS support

3) it is possible that Device guard will not need communication with wider world but if it does, hypervisor could manage network card and set a bridge, with different IP for each VM. Of course this implies only certain cards would work, see above

5) again, I do not imagine that this would work on any old PC, so again some kind of certification would be needed

Also, since my Windows already runs under a hypervisor (and plenty of business with their own VDI setup) it is imaginable that this solution would only work for some some setups, where Windows 10 is installed bare metal on supported (and certified) hardware. All in all, I think it's a win for average consumer.

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Bronek Kozicki
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Re: IOMMU?

I suspect you are slightly confused here. To start with, IOMMU (as implemented in modern PCs) relies on hardware level isolation provided by CPU and PCIe root complex and managed by the hypervisor, i.e. lower level than kernel of a virtual machine. The innovative part in Windows 10 design is that the OS itself (as seen by the user) is actually a virtual machine with all PCIe devices passed through, running on top of a hypervisor, alongside with a different tiny virtual machine called Device Guard. Hardware level isolation is required to ensure that device passthrough will not be used to hack Device Guard (or hypervisor) from inside OS seen by the user (i.e. virtual machine employing device passthrough).

Of course, since the hypervisor itself is presumably closed source Windows, this just moves vulnerability point away from the user, rather than remove it (which arguably cannot be done anyway). If Microsoft used open source for hypervisor and Device Guard that would be really innovative (for them), nevertheless this seem like a good step to me. Perhaps because it's similar to my own setup (two Windows 7 VMs running on top of single Linux hypervisor with kvm/vfio device passthrough for GPU , USB etc.)

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JetBrains releases CLion - new cross-platform IDE for C/C++ users

Bronek Kozicki
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Re: Promotional feature?

still, it is certainly interesting feature news for those who use both gcc and cmake

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Nvidia's GTX 900 cards lock out open-source Linux devs yet again

Bronek Kozicki
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Re: unfortunately, or perhaps ok....

Yes there is a patch (actually, it's official in both newer kernels, qemu and libvirt - no need to patch if you use the right version) but it only hides CPU type. Since then nVidia caught up and added detection of Hyper-V extensions which is a bummer - there is no patch for this, you either enable those or you don't. So, if you want to use newer nVidia drivers on a guest with consumer card, you are forced to disable Hyper-V extensions and some of them are actually useful at improving guest performance (timers, kernel spinlocks etc). Quite visibly, it's an arms race as you say. IMO it is entirely possible that in the future nVidia will tighten the screw again, doing something which will make it even more difficult to use consumer GPUs under virtual guest passthrough. I do not want to take this risk, thus will be staying with Radeons.

In fact, I just started little research of my own into GPU passthrough of a single slot water-cooled 295X2 ... and the fastest single slot nVidia you can buy is K4200 which is waaay behind this (but costs about the same, because it says "Quadro" on the box)

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Bronek Kozicki
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Re: yeah, sounds familiar

... and my home computer is actually a VDI running on Linux kvm/vfio with GPU passthrough for two Radeons, to two Windows guests. It's perfectly good for gaming, just ask my sons. From above you can also guess why I do not expect to replace these with nVidia ... ever. And I do not need to pay VMWare either, there is nothing wrong with kvm.

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Bronek Kozicki
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yeah, sounds familiar

Ask RedHat developers why they do not recommend consumer nVidia GPU for passthrough in kvm/vfio .... similar reason, the drivers in guest Windows detect they are being run under kvm and refuse to work. This is only to force the user to spend few hundred (or thousands, depending on model) more on a Quadro card, which is not better from guest perspective in any other way, except to allow this use.

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Samsung's PCIe flash card: Slim, speedy, and just nibbling power

Bronek Kozicki
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why downvote, it's a good question. You can implement either against PCIe interface of a M.2

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It's 2015 and a RICH TEXT FILE or a HTTP request can own your Windows machine

Bronek Kozicki
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Mushroom

I guess you only installed first batch of updates and forgot to press "Check for updates" to see a whole lot more updates for the updated "Windows update". Among which will be second update to "Windows update" after which you will have to restart, and again will be blissfully unaware that you are not even half-way through the process. Because that's the Microsoft Way, doh.

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Bronek Kozicki
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... and the long, long process of applying each one of them, with obligatory multiple restarts in the middle of the process. As opposed to installing one service pack (whose total size is a fraction of total size of patches) which applies all patches in one go.

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HGST says its NVMe flash card will manage 750,000 IOPS

Bronek Kozicki
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Re: Very cool

SLOG device and L2ARC cache on a busy ZFS server ...

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Aluminum bendy battery is boffins' answer to EXPLODING Li-ion menace

Bronek Kozicki
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Coat

Re: Bored of Battery "Breakthroughs"

"... to win a grant" ... or just someone taking on popular topic for PhD work, as simple as that.

Mine is the one without any academic papers in pockets.

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VirtualBox v. 5.0 beta 1 spins up for desktop virty lab chuckles

Bronek Kozicki
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Re: Key question: does it support accelerated 3D?

For Windows gaming, you could use GPU passthrough feature of kvm, if 1) your CPU supports PCI device virtualisation (this is called VT-d by Intel, do not confuse with VT-x) 2) you are lucky to own compatible GPU (newer AMD models are mostly good) and compatible motherboard. That's how I run 2 Windows instances on top of oversized headless Linux (with 2 GPUs, two keyboards etc., each for one Windows). You can find more on such setup in ArchLinux forums.

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Bloke faces 25 years in the cooler for upsetting Thai king on Facebook

Bronek Kozicki
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Re: Warning to The Register

Well, tough on you then I'm afraid. You may need to find other ways of reading The Register, I heard Tor Browser is gaining in popularity.

I am very much in doubt The Register would stoop to censoring its comments section (or actual articles), especially for sake of some backwater dictatorship.

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Belgium to the rescue as UK consumers freeze after BST blunder

Bronek Kozicki
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Re: GMT/BST and working with Americans

@VP that is exactly where one extra hour came from (time difference to UK was 4hrs instead of the usual 5hrs).

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In-depth: Supermicro's youngest Twin is a real silent ice maiden

Bronek Kozicki
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Re: Supermicro

Many SuperMicro boards have LSI chip onboard (usually 2308), with a choice of firmware either HBA or RAID. Depending on motherboard you will have different sockets for those extra drives. Allows for nice SAS RAID solution without hassle of extra card.

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Bronek Kozicki
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Re: Deduplication?

Right. I am well aware of RAM requirements of ZFS deduplication which is why I'm not using it and not recommending it. With this out of the way, lets talk about SLOG.

As mandated by POSIX, ZFS will by default complete all synchronous (as requested by caller) writes before returning to caller. Also, any metadata changes in ZFS are performed synchronously. Many filesystems use journal for this purpose, ZFS uses ZIL, i.e. ZFS Intent Log which is either carved from storage space of your volume, or placed on dedicated volume depending on 1) presence of "log" device 2) option logbias . Also, ZIL can be explicitly disabled (thus making filesystem behaviour for synchronous writes non-compliant with POSIX)

Now, assuming that ZFS setup has not been "optimized" either by "logbias=throughput" or "sync=disabled", there is big benefit from having dedicated log device with low latency, because that allows all synchronous writes to complete after intent has been written to such dedicated device (as opposed to writing to data volume with large latency). Looking at latency figures, ZeusRAM is up to 0.023ms and Intel P3700 is around 0.02ms (however, ZeusRAM capacity is only 8GB and P3700 starts at 400GB - which leaves lots of space for other purposes such as L2ARC, however we do not know max latency of P3700 only average). This number should be compared against latency of spinning rust storage (or whatever is used for main data volume) which typically would be somewhere between 2ms - 12ms depending on specific HDD in use. This means that synchronous writes would complete much, much faster if dedicated log device such as ZeusRAM or Intel P3700 was used. Normally this could significantly boost IOPS number.

However, what we do not know is whether 1) Maxta does actually use synchronous writes 2) its underlying ZFS ZOLVs are not "optimized" to avoid using ZIL. It would be interesting to learn this.

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Bronek Kozicki
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Re: Deduplication?

You mean, ZVOLs? They can make good use of both SLOG and L2ARC as well.

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Bronek Kozicki
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Deduplication?

I guess that's ZFS running there? If so, one upgrade I can recommend is small(ish) Intel P3700 for both SLOG device and L2ARC. I'm pretty sure that will push IOPS bit higher (I'm using such setup, but without dedup)

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Chipzilla spawns 60-core, six-teraflop Xeon Phi MONSTER CHIP

Bronek Kozicki
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Re: Memory

Nah, many computational real-time tasks require lots of CPU power and parallelize well, but do not use much memory at all. I guess if I was to use such a machine, 16GB of near RAM would suffice for most purposes (except for file buffers of course)

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Bronek Kozicki
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Re: The Platform

It's new to me too, but I like breath of the articles there. Only had time to read one on Xeon Phi which could be said to be remotely related to work (need to always have long-term strategy, right?)

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All the flash world needs is more TLC, suggests report

Bronek Kozicki
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Re: Let's hope they fix the data degradation problem

Also, checksums in filesystem will not speed up reads of degraded memory cell. Either the read will fail completely, possibly after long wait (in which case checksum + redundancy will aid the filesystem in transparently recovering the data), or it will take a long time because underlying hardware will need this much time to read all cells reliably.

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European Space Agency demos MARS LANDINGS BY DRONE

Bronek Kozicki
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Boffin

small issue of air density

This experiment is not going to deliver most robust results, as far as drone flight is concerned. They would have to repeat it under atmospheric conditions similar to Mars - that is air pressure 0.6% of Earth's at sea level. It will be very challenging to generate enough lift from reasonably sized rotary wing aircraft (e.g. drone) in such conditions.

My guess is that they were actually testing dropping rover on a surface using sky crane, not actual drone (to which rover was attached). It's just so much cheaper to use drone rather than rocket engines.

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I see you have the gTLD that goes .ping!

Bronek Kozicki
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Wait, ".int" ? What does that stand for?

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BT Home Hub SIP backdoor blunder blamed for VoIP fraud

Bronek Kozicki
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Re: Whats the point of home SIP anyway?

"guarantee 24/7 uptime for emergency" none will guarantee that. Your old POTS line also does not come with a guarantee either (even though most people assume that it does). That's what you want multiple phone connections for (mobiles do count). However I can recommend a good ISP for you, see my other posts.

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Bronek Kozicki
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Re: Whats the point of home SIP anyway?

@AC I suggest you change your ISP. Seriously, you obviously never had a good one.

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Bronek Kozicki
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Re: Whats the point of home SIP anyway?

I too would assume that "block all ports" means just that. The argument that it needs to be opened for the service to work is not a valid one in my view, because in that case the person doing so would at least be aware that they had opened a port, and could consider the implications.

Yes obviously you are right, it is person setting up SIP who would open this port, and only to certain IPs. SIP setup is well documented, I for one used http://wiki.aa.net.uk, because that is also my SIP provider (in addition to being my ISP).

It is BT fault that there seem to be no way to properly close ports on their modem, and SIP is just a background here really - they seem to have done the same with SNMP , for f*** sake!

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Bronek Kozicki
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Re: I wonder what other ports are open on the Home Hub ?

Please to let us know if 161 is open on yours, too

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Bronek Kozicki
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Re: A few at fault here

You pose valid question here, however please note that setting up SIP behind NAT is tricky enough as is, and it is actually valid to assume that if the firewall says that all access from outside is closed, then inbound communication is only allowed as a result of stateful NAT taking place inside the firewall. The "ASSUME" is the naiive part, but it's not actually as bad as you seem to make it.

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Bronek Kozicki
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Oh my ... that's SNMP.

It would seem that BT consistently prioritises support cost over security of users. That's not very good, but the silver lining here is that, perhaps, a small company of solicitors can convince BT to change its ways.

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Bronek Kozicki
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Re: Whats the point of home SIP anyway?

I have home SIP, the reason is that I gave up BT phone line after I got fed up with daily cold calls from various scammers (insurance etc.). After the experience I decided that I need not a one number, but a whole range of numbers, of which one number will go to close friends and family and others to various other places. After the move I quite liked the experience and also, for many international calls I make (both Europe and US) the call quality turned out to be much better than BT, and also significantly cheaper - an order of magnitude or so.

At this moment, to me the question is not "why would home user want SIP" - it is "why not want it", with one possible answer "lack of skills and motivation to learn". Which is pretty lame on ElReg, I think you will agree.

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Bronek Kozicki
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Re: A few at fault here

Downvote from me, because 5060 only needs to be open to certain IP address(es), owned by your SIP provider (in this case Voipfone). Which would be enough to protect from intrusion.

You would know it if you have ever setup a VoIP base station, but I suspect you never did.

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Bronek Kozicki
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@AC Right, in a way you are right.

If you buy vegetarian food, then you do not get certain proteins of animal origin as well. However you might have missed the point that some people do buy vegetarian food exactly for the reason that they only want proteins of non-animal origin.

Similarly, someone might want to disable all incoming traffic exactly for reason of preventing their IP PBX being hacked, and then add an extra rule to open port 5060 to only IP address(es) specified by their own SIP provider. At least that's what I do and I imagine that's common sense. Why would anyone want to open 5060 to everyone I do not quite understand (*), and why would a firewall insist to keep it open despite configured to keep it closed is ... well, that's pretty severe and I do hope that BT receives kicking for this one.

*) one theory being that one might want to use direct RTP communication with the world, but that's not actually very convenient given exposure to cold calls from everywhere and from all time zones (security aspect aside!)

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HUGE Aussie asteroid impact sent TREMORS towards the EARTH'S CORE

Bronek Kozicki
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Re: Silly question .... how old is the moon?

I thought about this, too. But then it occurred to me that Moon would have been formed over 4 billions years ago, when Earth did not even had (much of) crust. It must have been all pretty fluid at the time, which is exactly what allowed the Moon to form into a nice round shape - and Earth not to lose its round shape, too.

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AT&T, Verizon and telco pals file lawsuit to KILL net neutrality FOREVER

Bronek Kozicki
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Paris Hilton

I wonder

... will this court action hit Verizon back, again? I mean, it is remotely possible that the court will rule that, for one reason or another, the rules need to be amended to include more regulation, not less. For example, local loop unbundling.

That would be funny. (in lieu of dreamer icon)

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Complaints against ISPs and mobe firms are up by a fifth — reports

Bronek Kozicki
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ZEN

I was with Zen. They are not bad, but when faced with occasionally very noisy line they won't be able to fix it - you are on your own. Or, you can move to AAISP who know their stuff - including how to make BT fix the line. One downside - they cost more. And the upside - they are xkcd/806 compliant. Really, I tested.

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Fanbois: We paid $2000 for full satisfaction but now we have SPREADING STAINS

Bronek Kozicki
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Re: Feh...

@Mage of course you are right, but you missed a sentence. Let me finish it for you:

Laptop over £1000 gives you a nice shiny toy, not a serious content creation tool 12 hours day.

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Bronek Kozicki
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Coat

interesting problem

If I bought a monitor from reputable vendor (NEC, for example) I would expect my complaint regarding picture quality to be taken seriously and covered by the guarantee. I very much doubt NEC or other serious monitor vendor would claim that permament stains in the active portion of the monitor are "cosmetic damage".

And yet Apple claims that these are cosmetic damage and thus are not covered by the guarantee - even when in the middle of the screen. Even more interestingly, the product is marketed and sold on the basis of its looks. When the looks are gone, what remains?

That is one to watch, I will grab my popcorn.

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Apple boots Windows 7 out of Boot Camp

Bronek Kozicki
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I thought Windows 7 is not compatible with pure EFI mode, it seems to require INT10 which is only available through CSM. At least, that's what I found on https://technet.microsoft.com/en-us/library/hh824898.aspx although I do not insist that my interpretation is correct.

I guess the deal is that Apple does not want to support CSM any more, which would be required to install Windows 7. Not that I care, I run my Windows as virtual machines on "oversized" PC where hypervisor is Linux kvm.

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Apple's portable power podule patent promises paroxysms of fanboi joy

Bronek Kozicki
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Joke

why would anyone bother with separate device?

My phone's battery live already extends in days, why would this be needed?

... ooh, it is specifically for Apple phones and I do not have an Apple. Duh, silly me.

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A day may come when flash memory is USELESS. But today is not that day

Bronek Kozicki
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why no mention of Everspin?

they seem to have actual working MRAM, used by LSI and Dell. Unless it is no longer used or for some other reason "does not count" ?

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OpenSSL preps fix for mystery high severity hole

Bronek Kozicki
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Re: "has to be written in C"

Even though C is not my favourite language, I refuse to bash it on the basis of "being old" or ill-suited or something. Its strength is simplicity of design, and while personally I like (or even, demand) more refined languages to manage coupling and complexity of my own software projects, I am full of awe to those who manage to make very complex projects without such language features, in C. Linux kernel and GCC are two examples of such projects.

OpenSSL? Not so much, it was borked from the very beginning by the attitude of its developers "lets keep all features and platforms in, ignore all the standards and instead code all basic platform features ourself, no matter how irrelevant or possibly harmful it could be in the future" - but this has nothing to do with language and everything to do with culture. While each language comes with its own culture (set of idioms, support for certain design paradigms, approach to software design etc) there is nothing in C that would dictate such broken design - quite the opposite, actually. It's simple language that can be best characterised as "more elegant weapon for a more civilized age" but, like any weapon, it can be misused.

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