Re: Audacity and Gentoo

On Tue, 17 Jan 2006, Ian Rawlings murmured woefully:
> On 2006-01-16, Nix <nix-razor-pit@xxxxxxxxxxxxx> wrote:
>
>> Oh, yes, but that light is *useful*; it tells me if the fans have
>> failed. (There's also a software flag that gets raised, and the
>> system sends me an email accordingly.)
>
> You could try some small tabs of plastic on the fan blades, if the
> buzzing sound stops, the fans are whacked.

Yeah! Add extra noise in the service of reducing noise!

> Hmm, I'm full of useful suggestions today.

:)

>> Sheer because-it-was-theredom :)
>
> One of the driving forces behind progress!

.... and stupidity: to wit, Oracle*Mail and Oracle*Office, at which I
have been cursing for days. I can just imagine the discussions in the
Oracle Black Helicopter Base in Antarctica: `Hey, we've got a database,
what shall we use it for?' `How about an email client? We can make it
really, really awful, and sell it to existing customers. We already know
they're gullible idiots or they wouldn't be buying anything from us.'

> Not to mention early death.

So true. Although I must suggest that my brother's decision to use the
same umbilicus as me was *especially* stupid and led to Darwination
about as fast as is possible.

(although of course the Darwination was unsuccessful as he had a hot
spare.)

>> Wow. That's a lot simpler than I thought. It may be simple enough even
>> for me. I might try and see if I can make one sometime this year.
>
> It is dead simple, if a lazy git like me can be bothered to do it,
> then it has to be. It's been working without fault for probably about
> 4 years or so too.

But I just *know* that if I build it someone will blow up Rugby.

>> OK, you have worse radio reception than me :)
>
> Can only get 4 channels with rotten reception unless I take the
> Murdoch shilling, can only pick up radio 4 when using the TV aerial to
> receive,

.... while I'm located 2km or so from one of the largest TV and radio
transmitters in the country, which transmits just about everything
*other* than Radio 4. Guess what the only radio station I listen to is?

For a year I couldn't receive it at all because the transmitter was off
the air. Scuttle*** said someone had burned it down, but, uh, how do
you burn down a transmitting aerial? It's *metal*!

(Heat it up enough, I suppose, and anything will melt...)

> to get anything better needs satellite dishes or expensive
> external aerials. Still get to pay the full TV license though grumble
> mumble.

It took me some effort to stop the licensing idiots coming around at
times when I wasn't there to confront me over nonpayment and sending me
legal threats.

> I've got two internet NTP sources, which I regard as one source (as
> they come over a medium that reduces accuracy), one radio clock
> attached to the serial port of a machine (that's counted as another
> source as it's not subject to net delays), then for extra checking I
> have a wristwatch that syncs to a radio signal from Germany (a third

How on earth do you synch that with the computers? Don't tell me
there's wristwatch support in NTP!

> source, as it doesn't use the Rugby transmitter like the radio clock),
> and finally an alarm clock by my bed that syncs to the Rugby
> transmitter. If any of these agree with my wristwatch then I'm happy
> to say that they're both accurate as it's not likely that they're all
> syncing to a source that has the same error.

I just turn the radio on at 7am and listen for the beeps. Yeah, they're
delayed by a few seconds...

> I also have a
> 70-year-old clockwork wall-clock that I've tuned to only lose about 20
> seconds a month

I have a 110 year old clockwork alarm clock. I have to retune it; even
I think that gaining 25 minutes a day is a bit much.

> but that's mostly for fun. Oh and my car radio syncs
> to RDS (which is normally accurate on radio 4) and my palm pilot syncs
> to my desktop machines.
>
> I need to get out more.

.... to buy more clocks?

>> (But I had to synch *closely* when I was using Coda. If the time is more
>> than a second out between replicated Coda servers, Coda throws a
>> wobbly.)
>
> A *second*! I freak if my machines disagree by more than about 50
> milliseconds....

I'm not sure I'd easily be able to tell. My bacon was saved until
recently by the inability of anything I used to preserve subsecond
timestamps, but that's slowly changing now... ext[23] still don't go
below a second, so make(1) doesn't care if I'm off by much less than
that...

>> Run the wires in conduit down the edges of the room, stick tower cases
>> in the corners of rooms between desks and bookshelves and wardrobes, and
>> abhor desktops.
>
> I used to do similar, but it's a PITA when you need to extract a
> machine for furtling. With the rack, I can remove the plugs from the
> back and slide the machine out the front, then just slide it back in
> afterwards and cable it up. All the wiring is cable-tied into the
> rack. Racks exist for a reason ;-) You can get them for about £100 on
> ebay. Previously I'd have machines on their sides under desks with
> the rears facing outwards to aid in re-wiring but it never was quite
> as convenient.

That would be a good idea, if I had more than one rackmountable box.
But a rack for one machine seems like... overkill.

> Now they're all piled up in a 6-foot cabinet. The rack itself has
> just 6 cables running to it, one network cable for downstairs, one
> ADSL cable, 2 power cables (one for UPS, one for non-UPS), one network
> cable for the desktop and build area, and one long KVM cable to attach
> to the monitor/keyboard/mouse ports of machines I'm building.

Err, don't you need more than one network cable? Or is there a switch
in there too?

(And as for running a whole rack off two domestic power sockets, well,
it's pushing it, I'd think.)

> It might seem a bit extreme for a home network, especially when you
> consider that I have another two racks awaiting use (one will be set
> up in the next few weeks), but I work almost exclusively from home,
> that's my excuse!

There's no such thing as `too extreme': home is where you practice stuff
that's too elaborate or extreme or experimental for work :)

>> It seems to work; the only wire I normally see is a 20cm
>> length of network cable in my bedroom that I haven't bothered to wrap in
>> conduit yet. (Oh, and the places where the conduit stops and the cable
>> wriggles through holes in walls and that sort of thing.)
>
> Hey even *I* don't have computers in my bedroom ;-)

When I'm ill it means I can read news from bed. (In its spare time aside
from that it runs my news server, a postgres server instance, a
secondary nameserver, and the complex of two intrusion detection systems
and two virtual machines implementing my firewall. Well, one working
virtual machine and one broken one I have to fix.)

> Mind you given
> that I work from home, I can justify giving a room over to an office,
> in fact it's pretty much a requirement to stop meself going loco!

You've got a bigger house than me, then, although I guess my living room
could be called an office (being dedicated to books and computers. TV?
What is that?)

>> I'll have to see if there's a Linux port of that :) I haven't played it
>> since, oh, the early 90s? The late 80s? Something like that.
>
> I played R-Type for about an hour today and got further than I've ever
> got before, what joy ;-) Robotron is manic, I won't play that tonight
> as I've had a gin and tonic, ruins the concentration. A belt of
> coffee tomorrow then off to save humanity again.
>
> As for a linux port, just install xmame, you can either grab the 15
> gig or so of ROMs via bit-torrent or just ask me for specific ones.

I, er, think I'll wait until I fit that new disk. (15Gb?! Good grief.)

> Indeed, a friend of mine is a Doctor in Distributed Virtual Reality,
> the complexities of throwing a ball to someone on the other side of
> the world in a scalable (up to thousands of users) manner is quite
> incredible. He has to write reams and reams of Z notation to figure
> it all out properly.

Oh yes, that sort of thing is *hard*. There are a pile of experimental
notations to try to reduce the amount of Z scutwork you have to do if
you're Zing it all by hand (and in English? don't be ridiculous. I'm a
great fan of designs in English but I recognise that sometimes it's
a bit too much.)

>> The expirer does that, and it's not simple. However I did find a bug in
>> the design yesterday that would have accidentally expired files
>> corresponding to currently-visible inodes, and another bug today that
>> would have led to:
>>
>> bar
>
> All roads lead to "bar".

.... specifically, a bar crowded with journalists.

> Distributed *anything* is a PITA frankly...

Oh yes. (Thankfully the distribution part of Recant is easy. The hard
part is figuring out semantics for version control that are both useful
and don't conflict with POSIX. I think I've got it now. Time to
implement and see.)

>> Hey, I could use lzo...
>
> lzip was more efficient, it used lossy compression on common data, and
> you could tune it down to the accuracy you required, even to the point
> of ending up with compressing megabytes down to single bits.

Ah, I see it. What a useful tool! :)

There are lots of uses for lossy compression, just not for ordinary
data. (Hell, MP3 and Vorbis are premier examples.)

> Needless
> to say it was a spoof although UNIX implementations were produced.

Yep: Gentoo has packaged them :)

>> They seem to actually want to store *data* and then *retrieve* it
>> again. But then despite this they go and use Oracle. This contradiction
>> is incomprehensible to me.)
>
> Blimey, you're going to flip your lid if you're not careful. Mixing
> databases with filing systems is a recipe for madness.

Well, I guess that means if you're *already* mad when you start you're
bound to succeed, right? An excellent omen!

(Actually I'm using PostgreSQL to back it because I'm trying to make
my job *easier*, and avoid dealing with the storage-allocation crud
that normal filesystems have to spend so much time on. Modern disks
are so fast and modern caches so large that I can almost ignore the
I/O problem, and concentrate on the semantics, which is much more
interesting for a prototype. Nobody seems to have tried it before,
either: I can see projects that provide filesystem interfaces to
*existing* version control systems, but nobody seems to have tried
to come up with something that provides version control *and* doesn't
violate POSIX.

Not only am I not violating POSIX but I'm implementing everything FUSE
lets me, which pretty much means everything but ioctl()s. SELinux
labelling should work, as should ACLs, as I'm even supporting xattrs
(which is a godsend, actually, because all the extra version-rolling
features and so on can get implemented by reading and writing to virtual
xattrs :).

Just don't assume inode numbers are stable across reboots, or across
instances of the daemon if you start several on different machines.
They aren't remotely so (I'm handing them out sequentially, in fact),
POSIX doesn't require it, and if you have more than four billion files
open at once I'll have to give out several with the same `inode number'.

(Obviously I won't be testing that yet; I'd need several terabytes of
disk space to produce that effect. I'll just have to hope that part of
the code works. I'm not even sure PostgreSQL can scale to single tables
with that many rows, although I kind of hope it can...)

>> There is documentation in the download regarding what's *actually
>> there*. Note that like GFS it's designed with SANs and iSCSI and the
>> like in mind, and like GFS it doesn't *need* them and works perfectly
>> well on a reasonably speedy Ethernet network.
>
> Do you know if you can dynamically resize the Lustre filesystem
> *downwards* as well as upwards?

I'm not sure. I imagine it can cope with nodes dropping out, as both
Coda and Intermezzo can cope with network partitions and suchlike.

> What I'd like to be able to do is to
> create a "scratch" filesystem that uses spare space on other discs on
> my network, but I'd need to be able to conveniently (and perhaps
> scriptably) reduce the amount of space used by Lustre on occasion,
> depending on the needs of individual machines.

Why would you need local storage anymore for more than booting?

--
`Logic and human nature don't seem to mix very well,
unfortunately.' --- Velvet Wood
.