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Some time ago one of my disks in my Software RAID5 failed. No big problem as I had two spare A08U-C2412 available to replace that single 1 GB SATA disk. I can't remember any details but somewhat went wrong and I ended up with a non-booting system. I think I tried to add the HW-RAID as a physical volume to the LVM and thought of migrating the SW-RAID to the HW-RAID or do mirroring or such. Anyway: I booted into my rescue system that was on a RAID1 partition on those disks, but LVM didn't came up anymore, because the SW-RAID5 wasn't recognized during boot. So I re-created the md device and discovered that my PV was gone as well. =:-0

No, big deal, I thought, because I have a backup of that machine on another host. I restored /etc/lvm and tried to do a vgcfgrestore after I re-created the PV with pvcreate. First I didn't use the old UUID, so vgcfgrestore complained. After creating the proper PV with UUID LVM did recognize the PV, VG and LVs. Unfortunately I can't mount any of the LVs. Something seems to be broken:

hahn-rescue:~# mount /dev/vg/sys /mnt
mount: you must specify the filesystem type

Feb 19 07:50:02 hahn-rescue kernel: [748288.740949] XFS (dm-0): bad magic number
Feb 19 07:50:02 hahn-rescue kernel: [748288.741009] XFS (dm-0): SB validate failed

Running a gpart scan on my SW-RAID5 did gave me some results:

hahn-rescue:~# gpart /dev/md3

Begin scan...
Possible partition(SGI XFS filesystem), size(20470mb), offset(5120mb)
Possible partition(SGI XFS filesystem), size(51175mb), offset(28160mb)
Possible partition(SGI XFS filesystem), size(1048476mb), offset(117760mb)
Possible partition(SGI XFS filesystem), size(204787mb), offset(1168640mb)
Possible partition(SGI XFS filesystem), size(204787mb), offset(1418240mb)
Possible partition(SGI XFS filesystem), size(1048476mb), offset(1626112mb)

*** Fatal error: dev(/dev/md3): seek failure.

These is not the complete lists of VM as a comparison to the output of lvs shows:

hahn-rescue:~# lvs
LV VG Attr LSize Pool Origin Data% Move Log Copy% Convert
storage1 lv -wi-ao-- 1.00t
AmigaSeagateElite3 vg -wi-a--- 3.00g
audio vg -wi-a--- 70.00g
backup vg -wi-a--- 1.00t
data vg -wi-a--- 50.00g
hochzeit vg -wi-a--- 40.00g
home vg -wi-a--- 5.00g
pics vg -wi-a--- 200.00g
sys vg -wi-a--- 20.00g
video vg -wi-a--- 100.00g
windata vg -wi-a--- 100.00g

Please notice that /dev/lv/storage1 is my HW-RAID where I stored the images of /dev/vg/-LVs to run xfs_repair and such on. Anyway, the sizes of the recognized XFS partitions by gpart is mostly correct, but some a missing and xfs_repair can not do anything good on the backup images on storage1. Everything ends up in /lost+found, because the blocks seem to be mixed up somehow.

What I figured out is, that my old RAID5 device was in metaformat=1.2 whereas the new one is in format 0.9. My best guess is now to recreate the RAID5 device with format 1.2, do a vgcfgrestore on that and have (hopefully!) a working LVM with working LVs back that I can then mount again. If there's anything else I might be able to try, dear Lazyweb, please tell me. Please see the attached config files/tarballs for a complete overview.

Side note: except for AmigaSeagateElite3, which is a dd image of an old Amiga SCSI disk, I should have a fairly complete backup on my second backup location, so there's not much lost, but I would be a real timesaver when I would be able to recover the lost LVs. Both systems are behind DSL/cable and have a limit of 10 Mbps upstream. It would take weeks to transfer the data and sending an USB disk would be faster.

AttachmentSize mdadm.conf_.txt954 bytes hahn-lvm-restore.tar.gz14.7 KB Kategorie: DebianTags: DebianLVMRAIDSoftware 

If you include the work that I have done in the theatre as a stage manager - I've been engaged in project management since 1989. 24 years is a long time to think about and practice a craft. I wrote a bit about how technical theatre seems to impact software project management. I've been writing about technology and project management since 2004/05 and I've been managing the builds of complex database driven systems since 1999. All of this has led to my using many different project management styles and tool sets.

I've submitted a session in Portland on just this subject.

Learn from my 18 years of Project Management Experience with Technology. I've done it all - cowboy, waterfall, extreme, and agile scrum.

Learn why...

• Waterfall doesn't always work
• Agile has a place, but isn't the holy grail
• Cowboy can kill the relationships you have with your stakeholders
• How "Fixed Scope" is a lie
• That a combination of approaches is the answer

Project management requires a blend of techniques and tools to effectively shepherd projects from ideation to release. We'll explore and discuss different tools and methodologies that can help make your project successful.

drupaldrupalcon portlandsessionProject Management

When doing performance assessment for large and complex sites to assess why they are not fast or scalable, we often run into cases where modules intentionally disable the Drupal page cache. Depending on how often it happens and for which pages, disabling the page cache can negatively impact the site's performance, be that in scalability, or speed of serving pages. How to inspect code for page cache disabling

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Episode Number:  111 Post Topics:  Drupal Drupal 7 Module Development Drupal Planet Javascript

Learning module development in Drupal is not easy, but this Daily Dose of Drupal episode provides a very simple but practical module development video tutorial to use when learning about Drupal Module development. If you have a complex form on your Drupal websites, whether it is a Node creation form or perhaps even a webform, you may want to warn users before they navigate away from the page. This can help inform users that if they navigate away from the page before submitting the form, they may lose the contents of the form.

DDoD Video: 

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A new Rcpp master class is scheduled for March 9 in New York. The format will an updated version of the one-day workshops I have given at the University of Rochester in 2010, in San Franciso in 2011 (organised by Revolution Analytics) and at the UseR! conference in 2012.

The style will be hands-on, with numerous concrete examples and solid coverage of most aspects of Rcpp and related packages. As before, about six hours of instruction, split into four sessions of around ninety minutes focussing (loosely) on motivation/intro, core parts, extensions and applications. This should leave ample time for informal discussions and Q+A---as well as for lunch and coffee breaks---for a total of eight hours in the classroom.

This is being put together in New York with the help of Jared Lander, and we will have some technical assistance from RStudio in order to use their EC2 farm for exercises with Rcpp.

Registrations details are available here; information about other Rcpp events is also available.

Feel free to contact me or Jared at our usual email addresses with questions.

My lovely wife Jo has signed up for a charity event in May this year. To help support the UK Fire Fighters Charity, she has committed to a sponsored driving challenge. If she can raise enough funds in sponsorship, she'll get to drive a fire engine, a tractor and (it's rumoured) maybe even a combine harvester too! I've chipped in some money towards the total already; I'm sure Jo would love it if some other nice people pledged on her JustGiving page too.

Go on, it's for a good cause! :-)

Some of our customers are using central CUPS systems for managing their printer infrastructure. In the last years the demand for support printing (called Airprint) from mobile apple products increased. This worked well for us on Debian squeeze as documented here (updated scrips).

I tried this on a fresh installed Debian wheezy amd64, but no printer was found on any IOS device.

Hmm .... let's see if the printer is announces via avahi:

$ avahi-browse -a | grep -i print + eth0 IPv6 Kyocera FS-1020D @ service Internet Printer local + eth0 IPv6 AirPrint Kyocera @ service Internet Printer local + eth0 IPv4 Kyocera FS-1020D @ service Internet Printer local + eth0 IPv4 AirPrint Kyocera @ service Internet Printer local

WTF?!? Fortunately we have an Ubuntu 12.04 running in our office and printing from IOS devices works without problems (without copying any files to /etc/avahi/services/):

$ avahi-browse -a | grep -i print + eth2 IPv6 Ricoh Aficio MP C2800 @ printing Internet Printer local + eth2 IPv6 Ricoh Aficio MP 171 @ printing Internet Printer local + eth2 IPv4 Ricoh Aficio MP 171 @ printing Internet Printer local + eth2 IPv4 Ricoh Aficio MP C2800 @ printing Internet Printer local

I just copied the whole configuration over to my wheezy system, but it didn't worked out. I tried this all on a kfreebsd-i386 system again without success. Sorry, but I don't understand the source of this issue. Cups on wheezy has the same upstream version as on precise. Avahi-daemon on wheezy is just one minor version ahead off precise. Is this a bug/incompatibility in cups and/or avahi? A missing patch compared to the packages of precise?

Hints, rants and comments could be send to 'blog - at - waja - dot - info' or via @blogwajainfo.

It's a simple problem, but a serious one. You've put your content editors in front of Drupal for the first time, and they can understand the node form without any problems. They understand taxonomy terms, grok menus and node references… but they get nervous when it's time to save their work. "Will... will this be published as soon as I click 'save?'" Normally, there's no good way to make the distinction between saving and publishing a piece of content explicit. Site builders can set a content type to be unpublished by default, then give editors the broad "administer nodes" permission, but that's clumsy solution that forces editors to dig for what should be a simple action: publishing or unpublishing a post. That's where the Publish Button module comes in.

For those who are interested in the hypermedia part of Web Services, I wanted to call attention to a discussion posted in the WSCCI group, Proposing an alternative to application/vnd.drupal.ld+json.

Hello, World!

There are details coming out soon with regards to GSoC:2013, so all this is without any official hat of any sort on.

However, I had an idea, and I was wondering if there were people interested in mentoring it.

For a long time, I’ve wanted a Debian android application — one that will use API calls to fetch PTS info, BTS info, and intercept bug URLs to display Debian related information on the native interface.

It’d also be neat to set a profile (e.g. my emails) and get notifications when things happen that I care about.

Anyone know how to code for android and interested in GSoC?

If you are comming from an old SCM like subversion, you may have difficulties to internalize the new workflow.

Peter Cottle created Learn Git Branching which is really nice.

Thanks for the group hug!

Francesca started a DPL game and I've been mentioned a few times, by people I like deeply. Thank you! However I don't intend to run, and I hope I won't disappoint those who nominated me by saying so. But I don't think of it in terms of letting people down: I can't let anyone down since I never mentioned I'd like to run in the first place. Rather, I like to think that I've just received a wonderful group hug, and hey, wow, come here and let me hug you back! <3

And let me hug some more:

• Gregor Herrmann, I'm in a constant state of awe for what you have done with the Perl team. If you think that some of what you did could also be done as a DPL, please go for it!
• Bdale Garbee, I didn't think there could be such a thing as a reliable source of common sense until I got to know you. And you've been DPL and quite a good deal of other things and definitely know the drill. And you can't say you're busy with your day job. The last thing I want is for you to get bored after your retirement! :P
• Paul Tagliamonte, you seem to bring an incredible energy in everything you get involved with. Let's admit it: Zack's been a perfect DPL in many aspects, he has been incredibly, inhumanly smooth, but he was a bit boring. Zack has left Debian as a perfectly working train steaming on professionally towards awesomeness. Let's give it colours! Let's give it excitement! Let's give it creativity, and silliness! We need someone to cheer Christian up, and I if you can't do it, I can't think of anyone else who can!

I cannot think of a fourth DPL candidate right now and I don't want to postpone this post indefinitely. Think about it this way: you three are so good I can't think of a fourth one right now

There are actually lots of people I admire in Debian. I tried to name a few without thinking, but I wasn't thinking so I lost count as soon as I ran out of fingers. I know however that many enjoy to stay out of the spotlight and keep their fun focused on a few specific things. I am one of those myself.

Oh dear, FOSDEM was too short, can I have DebConf soon?

In the meantime, let's have some fun with the DPL campaign.

This webinar covers the basic questions around contributing to Drupal.org. Who should contribute? Why should users give back on Drupal.org? Joel Moore, Theming Specialist at Mediacurrent, walks listeners through the basics of contributing and provides practical examples that you can start using today. 

Drush is a Drupal developers Swiss-army knife. Of course there are the favorite commands that you probably use every day: drush sql-cli, drush pm-enable. Drush pm-download and drush pm-update are probably pretty commonly used as well. I'm going to use their aliases for the rest of this blog post: drush dl and drush up. drush up is actually a combination of drush pm-updatecode (drush upc) and drush updatedb (drush updb). In my examples I'll be using the Views module, but the same applies for any module or theme.

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It's that time of year again, my hair has all gone!

A new minor release RQuantLib 0.3.10 is now on CRAN and in Debian. RQuantLib combines (some of) the quantitative analytics of QuantLib with the R statistical computing environment and language.

The discount curve building code in QuantLib has shown some overly large numerical instabilities. We have used the same example parameters (taken from the Swap example in QuantLib) for years; it currently fails to solve for a rate at some term further out the curve. So I made the decistion to disable this just in the examples in order to not upset the CRAN testing framework. The examples now use a flat curve instead. I also updated one function to silence some new warnings from R-devel about symbols from another packages's namespace (in this case rgl, and it is just for surface plots, a purely cosmetic function).

Thanks to CRANberries, there is also a diff to the previous release 0.3.9. Full changelog details, examples and more details about this package are at my RQuantLib page.

Linux is a great platform for dealing with all kinds of different file systems, partition tables etc. But one of the few annoying situations when working in IT forensics are Microsoft Windows dynamic disks, AKA LDM (Logical Disk Manager).

Thanks to libldm’s ldmtool this is no longer true. A short demonstration from a real-life IT forensics investigation (actual IDs/data randomized for obvious reasons):

# ldmtool ldm> scan /dev/sdc* [ "1bad5bbc-a4b5-42e1-8823-001014b00003" ] ldm> show diskgroup 1bad5bbc-a4b5-42e1-8823-001014b00003 { "name" : "FOOBAR-Dg0", "guid" : "1bad5bbc-a4b5-42e1-8823-001014b00003", "volumes" : [ "Volume1" ], "disks" : [ "Disk1", "Disk2" ] } ldm> show volume 1bad5bbc-a4b5-42e1-8823-001014b00003 Volume1 { "name" : "Volume1", "type" : "striped", "size" : 3907039232, "chunk-size" : 128, "hint" : "D:", "partitions" : [ "Disk1-01", "Disk2-01" ] } ldm> show partition 1bad5bbc-a4b5-42e1-8823-001014b00003 Disk1-01 { "name" : "Disk1-01", "start" : 1985, "size" : 1953519616, "disk" : "Disk1" } ldm> create all Unable to create volume Volume1 in disk group 1bad5bbc-a4b5-42e1-8823-001014b00003: Disk Disk2 required by striped volume Volume1 is missing [ ] ldm> scan /dev/sdd* [ "1bad5bbc-a4b5-42e1-8823-001014b00003" ] ldm> create all [ "ldm_vol_FOOBAR-Dg0_Volume1" ] ldm>

The just created device mapper device then can be handled as usual:

# dmsetup ls | grep ldm ldm_vol_FOOBAR-Dg0_Volume1 (254:4) # mount /dev/mapper/ldm_vol_FOOBAR-Dg0_Volume1 /mnt/whatever

ldmtool just hit Debian unstable (and I intend to ship the tool with the upcoming version of Grml-Forensic).

I recently evaluated the Bakery Single Sign-On System aka Bakery SSO aka Bakery on behalf of clients. This article describes how I moved from finding a small weakness in version 2.x-alpha-3 to an exploit.

If you haven't updated all your sites to Bakery 2.0-alpha4 (6.x, 7.x), go and do so now.

Weblate recently got another new feature - charting of translation project activity.

It counts and charts daily contributions in last month and weekly contributions in last year and draws nicely looking charts out of that:

Originally I wanted to use some existing charting library and first implementation was actually done using PyCha, but in the end I ended up rendering charts using completely custom code, what allowed me to draw better graphs.

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So lately I’ve been coming across a lot of jQuery plugins and also some interesting Drupal modules that integrate them. It is more and more commonplace to see websites sporting all sorts of cool looking jQuery magic. Drupal is no worse I gotta tell you.