The first act was percussionist David Kuckhermann who played solo and then joined DCD for the main act. He mostly played the handpan, which looks a lot like an upside-down wok with dimples on it. His tambourine solo was oustanding. Overall, a great start to the evening. I hadn’t heard of him before, but I think I’ll be ordering some of his CDs.

Lisa Gerrard’s voice was, as always, trance-inducingly sublime and Brendan Perry with a fine voice of his own really shines in a live performance.

Definitely not a disappointment…around three hours of amazing performance, old favourites and new, and the discovery (for me) of a new performer. If I have one (minor) complaint, it’s that the volume was a little too loud, causing occasional distortion and difficulty distinguishing the lyrics on some of Brendan Perry’s singing. Lisa Gerrard sings without words – glossolalia – and much higher than Perry so wasn’t affected as much.

If you haven’t heard DCD or Lisa Gerrard’s solo albums before, do so – you’re in for a treat…labelled as “world fusion”, they’re impossible to describe accurately – while they started out as “Dark Wave” or as-goth-as-it-gets in the early 80s, they play across many genres and have strong influences from Middle Eastern, Mediaeval, world music, ambient, and more, they’re in a genre of their own. You can’t even say “they’re a bit like so-and-so” because they aren’t.

Dead Can Dance is a post from: Errata

First, I have to offer special thanks to “tshirtman” for being the first to unambiguously exemplify one of my main points. well done!

In case it’s not blindingly obvious (as it should be), the reason for my post was that I was outraged by the spectacle of one fairly high-profile member of the linux community trying to rally support to shun and exclude another fairly high-profile member because a nightmare had upset her.

WTF?

Is that really all it’s going to take to destroy someone’s reputation and perhaps their career? even with the shunning target’s own words available and archived to disprove the ridiculous straw-man mis-characterisations of what he actually said? Not one of the arguments against him actually addressed anything he said, they ALL attacked him for things he didn’t say, for things that other people claimed he said.

I was further outraged by seeing everyone who even suggested that questioning of stats (or, indeed, ANY claim of fact or evidence) may be, in some small way, a valid and reasonable thing to do get instantly put in their place and dismissed as Yet Another Rape Apologist.

Are we supposed to be anti-science, anti-scientific method now? or are rape stats a special case like religion where we are just supposed to switch off our analytical brains and accept what we are told on faith, without question?

Surely we are capable of better than that? i know we are capable of better than that. Or, at least, i used to know that. Now i’m not so sure.

In 2011, all it took was Ted Tso (“TT”) making some fairly reasonable statements about the need for any claimed evidence or statistics to be viewed skeptically and that dissenting research should also be considered – and he was instantly vilified as a “rape apologist”.

Sorry, but questioning extremely dodgy stats (that even in feminist circles are viewed more as ideological propaganda than as serious research) is NOWHERE NEAR SUFFICIENT to earn the label of rape-apologist.

That is not how debate works – you can’t just refuse to engage with someone’s point and simply accuse them of being the enemy for not agreeing 100% with whatever you say…at least, not if you have any intellectual honesty or self-respect.

(sure, some people are complete jerks and deserve to be told to FOAD in no uncertain terms – but a) jerks like that are self-evident and obvious, and b) TT’s participation in that thread was at all times civil and reasonable)

But that thread is ancient history – it was over and done with nearly two years ago.

In October this year, for reasons which are not at all clear, Valerie Aurora (“VA”) decided to revive the issue (which had been resolved back in 2011 with a resounding “fuck no, we don’t want misogynist shit or porn in our conferences” from pretty much the entire linux community – including near-universal support for improved anti-harassment policies both for linux.conf.au and for geek conferences in general) and use it to attack TT.

And she did so by twisting his words and claiming in a post on The Ada Initiative blog that he said something which he didn’t, that “rape was impossible if both people were drunk enough”. If he chose, he could quite easily win a libel case against her and TAI on that. It’s not what he said, it’s not even close to what he said, and VA is clearly too smart to honestly believe that it is what he said.

In another post on her personal, blog she talks about how what he said was so terrible that it even now gives her nightmares, and that she can’t bear the thought of working with him.

Again, WTF? VA can say “I had nightmares and was upset and furious” and THAT is enough to justify a call to shun TT?? He didn’t attack her, or threaten her (explicitly or implicitly), he was polite and civil. What he did was disagree with VA by referring to other research that disputed VA’s preferred studies.

I agree with and support many (perhaps most) of VA’s and The Ada Initiative’s aims, I certainly believe that linux and open source etc should be very welcoming and supportive of human diversity (including gender and sexuality, identity, religion, politics and so on), believe that it’s a good thing that The Ada Initiative exists as part of that diversity welcome to be particularly supportive of women in geekdom.

And i wholeheartedly agree that Linux leaders should not make public statements belittling and condoning rape BUT:

a) I haven’t seen one instance of that happening, ever

and

b) I find VA’s choice of tactics here to be despicable. as i do when anyone else uses similar tactics, because they ARE despicable tactics. They are exactly the same as accusing someone of being a child pornographer for being against net censorship: You dared to disagree with me so I’m going to accuse you of being a monster.

(and, i must admit, the enthusiasm level of my support for The Ada Initiative is somewhat….diminished…by this tactical blunder by the spokesperson and co-founder)

There are far more deserving targets of VA’s ire than TT. And there are far better ways for the Ada Initiative to achieve their aims.

Why?

So why did I decide to comment when I knew that I was inevitably going to be accused of “hating women” and being a “rape apologist?

Mostly because I thought it would be gutless of me not to.

Hardly anyone else had, and they quickly backed down under the accusations of misogyny…and since I consider myself to be psychologically fairly strong, I felt that I am capable of wearing a little shit (or even a lot) for a while. In my egocentric fashion, I thought “if I can’t do then it’s no wonder that no one else dares”.

And also because anyone who cared to make even the slightest effort to find out what my actual views on sexual harassment, rape, women’s rights and numerous inter-related issues are can fairly easily see a very consistent record of the kinds of things I argue for and against, and my scathing responses to actual misogynists when they appear on lists that I participate in. they are not my kind of people.

and even then, i hesitated. it’s scary and intimidating to be putting yourself forward to be accused of being one of the things you hate. this is, of course, an instance of the chilling effect.

So, I found the prospect scary, almost terrifying….and I can’t think of a single person who has met me online or in real life who would even remotely describe me as being any kind of delicate or sensitive wall-flower.

again, “if i can’t do it, it’s no wonder no one else dares”. so i clicked the “Publish” button. an ego is useful for some things.

Also, I took VA’s words “but don’t be silent” as inspiration.

In the process, i discovered why it is that some people just simply refuse to engage in rational discourse. I’ve seen it many times from the other side, but i’ve never experienced the seductive pleasure of indulging in it myself before – there’s a liberating freedom in just ignoring any and every point that someone makes and simply accuse them of being the enemy. You don’t have to try to understand what they wrote, hell you don’t even have to really read it…you just need to quickly scan it for overall tone and if they don’t seem like they’re 100% supportive, you just accuse them of being the enemy or an apologist for the enemy. it’s that fucking simple and easy.

well, sort of easy. easy for some, perhaps. i personally found it extremely difficult – a struggle – to refrain from engaging, to remain in character (i’m not much of an actor). especially when i kind of agreed with whoever was arguing against my experimental character or if i thought they made a good point. and even more so when i thought that some comments skirted a bit too close to being the kind of misogynist crap that i didn’t want to tolerate having on MY blog.

(i resolved that issue by just approving any reply that didn’t squick me or that i could squint at and think ‘hmmm…borderline, give benefit of doubt’)

but even though i don’t like it, i can recognise the attraction it holds for some people.

Other thoughts:

I’m particularly disgusted by the men who intervene way too early – without an explicit invitation or request for help or a clear need such as an immediate threat of violence – in womens’ issues.

Many or maybe even most may not realise it, but they are just taking over and asserting male strength and control by “protecting” women rather than giving them the support and space to discover and practice their own strength and their own voices. These uninvited interventions do not help women, they weaken and undermine them, they perpetuate dependence, they steal strength from the movement. It is patronising and enfeebling. But mostly, they just re-assert male dominance and are an attempt to make women’s spaces more comfortable, more palatable, for men.(*)

(it’s also quite often very transparent self-serving and ingratiating behaviour from blokes who want to lay the groundwork for perhaps getting laid one day)

IMO this goes far beyond a problem with men over-involving themselves in feminist causes – i feel the same way for any relatively less-privileged group with a need to find their own voice and their own power – they’ll never find it if members of the privileged class (i.e. white males like me) just ride roughshod over the movement and speak FOR them rather then just silently lending their strength in support. For the most part, they (we) should just shut up and listen…we already have more than enough opportunities to have our say.

(*) yes, i’m well aware of the difficulty in writing something like that paragraph as a member of a privileged class, without coming across as either self-hating or patronising or both. if i’ve failed here, it’s not for want of trying.

done is a post from: Errata

I can’t bear the thought that so many Linux people may secretly be Nazi seal murderers, so I demand that they be excluded from any future Linux-related events or conferences that I might wish to attend. My nightmare and the strength of my personal reaction to it are conclusive proof that they are guilty.

I can’t remember all those who were identified in my dream right now, so I need to be able to point the finger at any time in the future and have any individual shunned – excluded and banned from events, conferences, mailing lists, and open source projects in general…with any who communicate with them (or, worse, support the evil-doers by pretending to a moderate, reasonable, rational, and/or evidence-based stance) being likewise exiled.

After all, remember that even in these enlightened times there is still a seething culture of penguin-supremacism in the Linux community – overtly pushing the agenda of the pure penguin race over the pernicious and corrosive evil of seals….this culture of seal-murder must be stamped out by whatever means necessary. Zero tolerance for seal-murder apologists!

Thank you for understanding and supporting me in my very real fears. You make the world a safer place for everyone.

I had a dream… is a post from: Errata

In a recent upgrade (from Openstack Diablo on Ubuntu Lucid to Openstack Essex on Ubuntu Precise), we found that DNS packets were frequently (almost always) dropped on the bridge interface (br100). For our compute-node hosts, that’s a Mellanox MT26428 using the mlx4_en driver module.

1. Use an old lucid kernel (e.g. 2.6.32-41-generic). This causes other problems, in particular the lack of cgroups and the old version of the kvm and kvm_amd modules (we suspect the kvm module version is the source of a bug we’re seeing where occasionally a VM will use 100% CPU). We’ve been running with this for the last few months, but can’t stay here forever.

net.bridge.bridge-nf-call-arptables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-ip6tables = 0

Update 2012-09-12:

Something I should have mentioned earlier – this happens even on machines that don’t have any openstack or even libvirt packages installed.  Same hardware, same everything, but with not much more than the Ubuntu 12.04 base system  installed.

On kernel 2.6.32-41-generic, the bridge works as expected.

On kernel 3.2.0-29-generic, using the ethernet interface, it works perfectly.
Using a bridge on that same NIC fails unless net.bridge.bridge-nf-call-iptables=0

So, it seems pretty clear that the problem is either in the mellanox driver, the updated kernel’s bridging code, netfilter code.  or some interaction between them.

Interestingly, I have other machines (without a mellanox card) with a bridge interface that don’t exhibit this problem.  with NICs ranging from cheap r8169 cards to better quality broadcom tg3 Gbit cards in some Sun Fire X2200 M2 servers and intel gb cards in supermicro motherboards.  Like our openstack compute nodes, they all use the bridge interfaces as their primary (or sometimes only) interface with an IP address – they’re configured that way so we can run VMs using libvirt & kvm with real IP addresses rather than NAT.

So, that indicates that the problem is specific to the mellanox driver, although the blog post I mentioned above had a similar problem with some broadcom NICs that used the bnx2 driver.

openstack, bridging, netfilter and dnat is a post from: Errata

I started a bzr branch of calibre about 2.5 hours ago because I wanted to see how difficult it would be to understand the code and make a few changes. The calibre Get Involved page warns that it can take about an hour….which is excessive to begin with and, worse, a huge understatement.

$ date ; ps u -Cbzr
Sat Apr 14 15:10:00 EST 2012
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
cas      14279  3.0  1.3 286836 215976 pts/3   S+   12:39   4:36 /usr/bin/python /usr/bin/bzr branch lp:calibre

It's still far from finished.

cas@ganesh:/usr/local/src/calibre$ bzr branch lp:calibre
You have not informed bzr of your Launchpad ID, and you must do this to
write to Launchpad or access private data.  See "bzr help launchpad-login".
1395260kB    65kB/s - Fetching revisions:Inserting stream:Estimate 178815/203940

a git clone of a much larger project would have been finished in mere minutes. WTF is bzr so horrendously slow?

It's not my connection, I'm on an otherwise idle ADSL2 connection, that syncs about 14Mbps.  i.e. capable of downloads of up 1.4 megabytes per second, not the 50-70kB/s that bzr is dawdling along at.  It's not my CPU, an AMD 1090T hex-core overclocked to 3.7GHz (and almost completely idle)…and since I have 16GB RAM, it's not lack of RAM either.

Is there anything good about bzr that makes people actually want to use it?  or is it just the association with ununtu and launchpad?

maybe the purpose is to actively discourage casual involvement….you have to make a massive life commitment and run the gauntlet of tediously long waits before you can even look at the code.

No wonder github is so popular.

why is bzr so slow? is a post from: Errata

It was the admin-ssl plugin.  de-activated now, so comments are working again.

A few people tried to add comments according to the log – if you feel like making them again, go right ahead.

thanks

Craig

comments working again is a post from: Errata

So far, I like it. Much more than I thought I would as an unrepentant sh and perl using systems geek. And getting over my distaste for the white-space issue is also proving to be much easier than I thought it would (although I still think that block-delimiters like {} make the code easier to read…PyHeresy, I know)

While hacking the /usr/bin/glance command to have less ugly output, and adding a –csv option to list the image index in a usefully parseable format, I needed to figure out how to get the terminal size (height,width).

This, cobbled together from various google search results, seems to work. It’s probably not strictly-correct python idiom, and there’s probably a better way of doing it. Comments and critique are welcome.

def get_terminal_size(fd=1):
    """
    Returns height and width of current terminal. First tries to get
    size via termios.TIOCGWINSZ, then from environment. Defaults to 25
    lines x 80 columns if both methods fail.
 
    :param fd: file descriptor (default: 1=stdout)
    """
    try:
        import fcntl, termios, struct
        hw = struct.unpack('hh', fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234'))
    except:
        try:
            hw = (os.environ['LINES'], os.environ['COLUMNS'])
        except:  
            hw = (25, 80)
 
    return hw
 
def get_terminal_height(fd=1):
    """
    Returns height of terminal if it is a tty, 999 otherwise
 
    :param fd: file descriptor (default: 1=stdout)
    """
    if os.isatty(fd):
        height = get_terminal_size(fd)[0]
    else:
        height = 999
 
    return height
 
def get_terminal_width(fd=1):
    """
    Returns width of terminal if it is a tty, 999 otherwise
 
    :param fd: file descriptor (default: 1=stdout)
    """
    if os.isatty(fd):
        width = get_terminal_size(fd)[1]
    else:
        width = 999
 
    return width

getting the terminal size in python is a post from: Errata

This is good, but has caused my rsync backup to zfs script to complain about being unable to delete files in the .zfs directory (which is in the backup but not in the source).

e.g.

sending incremental file list
rsync: delete_file: unlink(.zfs/snapshot/2012-03-31/vmlinuz.old) failed: Read-only file system (30)
rsync: delete_file: unlink(.zfs/snapshot/2012-03-31/vmlinuz) failed: Read-only file system (30)
[...]
cannot delete non-empty directory: .zfs/snapshot/2012-03-31
rsync: delete_file: rmdir(.zfs/snapshot/2012-03-31) failed: Device or resource busy (16)
rsync: delete_file: unlink(.zfs/snapshot/2012-03-30/vmlinuz.old) failed: Read-only file system (30)
rsync: delete_file: unlink(.zfs/snapshot/2012-03-30/vmlinuz) failed: Read-only file system (30)
[...]

The solution is to tell rsync to ignore .zfs directories on the destination.

1. use the -F option to make rsync use /.rsync-filter
2. create or add the following line to /.rsync-filter

-r .zfs/***
-s .zfs/***

On the first line, the ‘-’ makes it an exclude rule, and the ‘r’ indicates that the rule applies to the receiving side. Together, ‘-r’ prevents rsync from attempting to delete the .zfs directories

On the second line, the ‘-s’ indicates that the rule applies to the sending side, preventing rsync from trying to backup any .zfs snapshot directories. This is only useful when backing up a ZFS filesystem.

rsync and .zfs snapshot directories is a post from: Errata

I’ve got two systems with XFS root partitions that fstrim seems to do (almost) nothing on, but it seems to work correctly on another system with formatted with ext4.

Details follow:

System 1 is an AMD 1090T with a Patriot Torqx 2 128GB SSD. System 2 is also an AMD 1090T with a Patriot Pyro 120GB SSD.

I’ve been running both for several months without any TRIM support because I (incorrectly) assumed that XFS’ support for TRIM was automatically enabled. I’ve recently discovered that it’s not, and also that it’s better performance-wise to run fstrim regularly from cron for ‘batch-mode’ TRIM operations.

Anyway, System 1 takes over 7 minutes to run fstrim, and claims to have trimmed about 16GB….but if i run it again it still takes over 7 minutes and claims to have trimmed about the same amount of data (slightly less).

# time fstrim -v /
/: 16777764864 bytes were trimmed

real 7m31.089s user 0m0.004s sys 0m9.705s

# time fstrim -v /
/: 16772276224 bytes were trimmed

real 7m8.973s user 0m0.000s sys 0m9.165s

System 2 takes over 28 minutes to run fstrim and claims to trim about 51GB of data (it’s had an SSD for a lot longer than System 1. It also has /home on /, whereas System 1 has /home on a separate disk). Similarly, running it again immediately afterwards also takes about the same amount of time and claims to trim about the same amount of data.

# time fstrim -v /
/: 51594948608 bytes were trimmed

real 28m19.832s user 0m0.000s sys 0m6.264s

# time fstrim -v /
/: 51499814912 bytes were trimmed

real 28m29.230s user 0m0.000s sys 0m6.328s

(interestingly, the Pyro is a *much* faster SSD than the Torqx2. it’s SATA3 and is capable of about 500-550MB/s. The Torqx 2 is SATA 2 and is capable of about 230MB/s…seems as if TRIM speed is roughly the
same for both drives, proportional to the amount of data to be trimmed. almost certainly limited by the flash speed with the internal controller differences being negligible for this task)

OK, so it seems as if fstrim claims X bytes were trimmed, but it doesn’t actually happen.

On a third system, I have / on an SSD formatted with ext4. System 3 is an Intel Xeon E5607, and the SSD is an OCZ AGILITY3 120GB.

# time fstrim -v /
/: 14267424768 bytes were trimmed

real 2m25.222s user 0m0.000s sys 0m0.636s

# time fstrim -v /
/: 0 bytes were trimmed

real 0m0.001s user 0m0.000s sys 0m0.000s

on ext4 fstrim seems to work as expected. The OCZ SSD is also a LOT faster than the Patriot SSDs (roughly 14GB trimmed in 2.5 minutes).

anyone seen this before? is it a bug in XFS’ SSD handling? or am i just misinterpreting the results? my google-fu can’t find anyone with similar problems, just mailing list articles and an XFS wiki page saying that it works, and that running fstrim regularly is recommended over using the ‘discard’ mount time option.

fstrim and XFS is a post from: Errata

Sometime within the last few months, an upgrade prevented Chromium from finding its application icon…with the result that when minimised (or displayed in the panel window list or Alt-Tab) it used the default application icon.

It looks to me as if the problem is that Chromium is now looking for chromium-browser.svg but chromium.svg is what's on my debian system.

To restore, all you need to do is:

$ mkdir -p ~/.local/share/icons/hicolor/scalable/apps
$ cd ~/.local/share/icons/hicolor/scalable/apps
$ ln -s /usr/share/icons/hicolor/scalable/apps/chromium.svg chromium-browser.svg

great, done. Now my chromium windows don't look the same as my mrxvt windows in Alt-Tab, they're quite clearly Chromium windows. The icon now looks like this: rather than an icon i'd insert here if i knew what its filename is – it looks like a white window with a blue title bar and a thinner blue bar at the bottom (about half the height/thickness of the "title bar") I've spent half an hour searching for it and have given up – anyone know what it is?

alternatively, use cp rather than ln – just in case some future upgrade removes or renames the chromium.svg file

How to set the application icon for chromium is a post from: Errata