dannyman.toldme.com


Linux

Merge Multiple PDF Documents

Link: https://dannyman.toldme.com/2012/06/09/e-pdfs-unum/

By the way, let’s say you have to print, sign, scan, and email back a document using the flatbed scanner attached to your Linux workstation. No trouble scanning in each page as an individual PDF document using XSane, but assembling the multipage project into one document proved a modest challenge last time I tried.

Solution? Install pdftk, and then the command goes something like:

pdftk AVID000*.pdf cat output AVID.pdf

That’s will merge all the documents named AVID0001.pdf, AVID0002.pdf, etc into AVID.pdf. Or to put it another way:

pdftk <a bunch of PDF files> cat output <target PDF file>

Cheers!

1 Comment


Linux, Technical, Technology, Testimonials

Dear Ubuntu: Stop Asking me for my Password!

Link: https://dannyman.toldme.com/2012/05/24/ubuntu-password-prompt/

I like Ubuntu. Or at least I liked it a few years back when you got a very nice functional desktop out of the box … but that is a different gripe.

I really like an OS that updates the software for me. Really, downloading and installing updates is for chumps! Way to go, Ubuntu!

But here’s a feature that has been bugging me for years: the system pops up a window saying “hey, I’m going to update the system software for you.”

And I’m like “sure, go ahead, be my guest!”

Then it’s like “okay, please give me the administrator password.”

And I’m like “well, okay . . . but . . .”

Each time the computer pops up a window unbidden offering to do me a favor in exchange for my password, I am wondering when some bastard will get around to writing a bit of malware that offers to do something nice for me in exchange for my password. Maybe a web site can launch a convincing-looking software-update window and prompt me for a password. It is going to be epic just how many users can be convinced to type their system passwords into a malware site.

If you are a part of the system that has access to do heavy lifting, please do not approach the user asking for a password. It teaches the user that “hey, its normal for your computer to pop up some window and ask for a password and when that happens you should totally humor the computer and give it your password.” You want to update my software? Great! You want to check with the person using the computer to make sure its a good time? Great, ask away, tell them your plans. But when they say yes, just fricking do it, and don’t ask them for their password.

1 Comment


FreeBSD, JIRA, Linux, Mac OS X, Technical

Strip Non-Ascii From a File

Link: https://dannyman.toldme.com/2012/05/10/mysql-not-configured-for-utf8/

I have had bad luck trying to coax this out of Google, so here’s a Perl one-liner:

perl -pi -e 's/[\x80-\xEF]//g' file.txt

Where file.txt is a file you want to clean up.

Why this comes up is because we have a web application that was set up to hit a MySQL database, which is incorrectly configured to store text as ASCII instead of UTF-8. The application assumes that all text is Unicode and that the database is correctly configured, and every week or two someone asks me why they are getting this weird gnarly error. Typically they are pasting in some weird UTF-8 whitespace character sent to us from Ukraine.

Eventually the database will be reloaded as UTF-8 and the problem will be solved. Until then, I can tell folks to use the Perl command above. It just looks for anything with the high bit set and strips it out.

Feedback Welcome


Linux, Technical

Notes: Make Ubuntu GUI Less Annoying

Link: https://dannyman.toldme.com/2011/12/07/ccsm-ubuntu-gui-tweaks/

First, install ccsm.

Terminal windows resize themselves stupidly when changing font size. I don’t know how to fix that, but in the CompizConfig Settings Manager, I can enable Resize Info to overlay the dimensions of any window as I resize it.

Often, when dragging a window around, it tries to go full-screen on me. This is obnoxious! Just disable Grid in CCSM.

If anyone knows how to reconcile Focus Follows Mouse with “menu bar at the top of the screen” I would love to hear it! Or if you know how to configure the pager to something besides 2×2 …

1 Comment


Linux, Technical

Latency Goggles for Linux

Link: https://dannyman.toldme.com/2011/09/09/netem-test-tcp-performance/

While diagnosing why an internal web site is slow for some users, I got data that our overseas colleagues see ping latency to the web site of around 200 ms. This is not unreasonable. Some web sites that attach a lot of additional objects cause remote clients to have to open several connections and make several round-trips to load and render a web page. What might work fine at 20 ms latency can really drag at 200 ms.

How to test this out? As a Linux user, I can use netem to induce added latency on my network interface:

# ping -qc 2 google.com
PING google.com (74.125.224.145) 56(84) bytes of data.

--- google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 5009ms
rtt min/avg/max/mdev = 4.136/4.197/4.258/0.061 ms
# tc qdisc add dev wlan0 root netem delay 200ms
# ping -qc 2 google.com
PING google.com (74.125.224.144) 56(84) bytes of data.

--- google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 5474ms
rtt min/avg/max/mdev = 205.006/205.034/205.062/0.028 ms

# tc qdisc change dev wlan0 root netem delay 0ms
# ping -qc 2 google.com
PING google.com (74.125.224.50) 56(84) bytes of data.

--- google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 5011ms
rtt min/avg/max/mdev = 4.117/4.182/4.248/0.092 ms

Note, I’m on wireless, so I’m tuning wlan0. you’ll want to hit eth0 or whatever is appropriate to your configuration.


The YSlow plugin or the Google Chrome Developer tool Network tab can be helpful to see what is going on:

Google Chrome's Developer Tool Network view without extra latency.

Google Chrome's Developer Tool Network view with extra 200ms latency.

So, with my web site, an added 200 ms latency doubles total page load time from 0.8 seconds to 1.6 seconds.

Here’s what I see when I visit the problem web site:

A problem web site at normal latency.

A problem web site at additional 200ms latency.

Total page load time at 7.5 seconds is nearly three times slower than without latency.


A very crude way to measure things is with wget on the command-line.

The wget man page mentions the -p (page requisites) option, then the author suggests wget -E -H -k -K -p <URL>. (You’ll need to RTFM yourself…) So I do:

$ cd /tmp
$ sudo tc qdisc change dev wlan0 root netem delay 0ms
$ time wget -q -E -H -k -K -p http://google.com

real	0m0.160s
user	0m0.010s
sys	0m0.000s
$ sudo tc qdisc change dev wlan0 root netem delay 200ms
$ time wget -q -E -H -k -K -p http://google.com

real	0m3.832s
user	0m0.010s
sys	0m0.000s

Of course, even with all those options, wget behaves very differently from a modern GUI web browser: there’s no caching, it doesn’t parse the DOM and it will blindly download requisites it doesn’t actually need. (Even a large font file found in a CSS comment.) And it does all its requests serially, whereas a modern GUI web browser will fetch several objects in parallel. And whatever web browser you use over a connection with induced latency is not going to replicate the experience of remote users pulling page requisites from zippy local CDNs.


At the end of the day, I proposed the following advice to my remote colleagues:

  1. Try tuning the web browser to use more concurrent TCP connections.
  2. Try modifying browser behavior: middle-click faster-loading sub-pages in to new tabs, work on those tabs, then refer back to the slower-loading “dashboard” screen, reloading only when needed.

I also tweaked the web application to make it possible to show a more lightweight “dashboard” screen with fewer objects hanging off of it. This seems to improve load time on that page about 50%.

Feedback Welcome


Linux, Sundry, Technical, Technology, Testimonials, WordPress

Updating WordPress: Upgrading php53 on CentOS

Link: https://dannyman.toldme.com/2011/07/05/wordpress-upgrade-php53-centos/

If you have a self-hosted WordPress blog, you really ought to keep it up to date. Popular software is a popular security target, and as new exploits are discovered, new patches are deployed. Fortunately, WordPress makes this super-easy. Just go to Dashboard > Updates and you can update with one click. I basically get a free update any time I get it in my head to write something.

Except this morning, when I was told that an update was available, but:

"You cannot update because WordPress 3.2 requires PHP version 5.2.4 or higher. You are running version 5.1.6."

On my CentOS VM, this was addressed by:


sudo yum update
sudo service httpd restart

Actually, it was a little difficult, because we’re replacing php with php53:

0-13:11 djh@www0 ~$ cat /etc/redhat-release
CentOS release 5.6 (Final)
0-13:11 djh@www0 ~$ rpm -q php
php-5.1.6-27.el5_5.3
0-13:11 djh@www0 ~$ yum list installed | grep ^php
php.x86_64                               5.1.6-27.el5_5.3              installed
php-cli.x86_64                           5.1.6-27.el5_5.3              installed
php-common.x86_64                        5.1.6-27.el5_5.3              installed
php-gd.x86_64                            5.1.6-27.el5_5.3              installed
php-mysql.x86_64                         5.1.6-27.el5_5.3              installed
php-pdo.x86_64                           5.1.6-27.el5_5.3              installed
1-13:11 djh@www0 ~$ sudo service httpd stop
Stopping httpd:                                            [  OK  ]
0-13:11 djh@www0 ~$ yum list installed | grep ^php | awk '{print $1}' 
php.x86_64
php-cli.x86_64
php-common.x86_64
php-gd.x86_64
php-mysql.x86_64
php-pdo.x86_64
0-13:12 djh@www0 ~$ sudo yum remove `!!`
sudo yum remove `yum list installed | grep ^php | awk '{print $1}'`
Loaded plugins: fastestmirror
Setting up Remove Process
Resolving Dependencies
--> Running transaction check
---> Package php.x86_64 0:5.1.6-27.el5_5.3 set to be erased
---> Package php-cli.x86_64 0:5.1.6-27.el5_5.3 set to be erased
---> Package php-common.x86_64 0:5.1.6-27.el5_5.3 set to be erased
---> Package php-gd.x86_64 0:5.1.6-27.el5_5.3 set to be erased
---> Package php-mysql.x86_64 0:5.1.6-27.el5_5.3 set to be erased
---> Package php-pdo.x86_64 0:5.1.6-27.el5_5.3 set to be erased
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package           Arch          Version                 Repository        Size
================================================================================
Removing:
 php               x86_64        5.1.6-27.el5_5.3        installed        6.2 M
 php-cli           x86_64        5.1.6-27.el5_5.3        installed        5.3 M
 php-common        x86_64        5.1.6-27.el5_5.3        installed        397 k
 php-gd            x86_64        5.1.6-27.el5_5.3        installed        333 k
 php-mysql         x86_64        5.1.6-27.el5_5.3        installed        196 k
 php-pdo           x86_64        5.1.6-27.el5_5.3        installed        114 k

Transaction Summary
================================================================================
Remove        6 Package(s)
Reinstall     0 Package(s)
Downgrade     0 Package(s)

Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Erasing        : php-gd                                                   1/6 
  Erasing        : php                                                      2/6 
  Erasing        : php-mysql                                                3/6 
  Erasing        : php-cli                                                  4/6 
  Erasing        : php-common                                               5/6 
warning: /etc/php.ini saved as /etc/php.ini.rpmsave
  Erasing        : php-pdo                                                  6/6 

Removed:
  php.x86_64 0:5.1.6-27.el5_5.3            php-cli.x86_64 0:5.1.6-27.el5_5.3    
  php-common.x86_64 0:5.1.6-27.el5_5.3     php-gd.x86_64 0:5.1.6-27.el5_5.3     
  php-mysql.x86_64 0:5.1.6-27.el5_5.3      php-pdo.x86_64 0:5.1.6-27.el5_5.3    

Complete!

0-13:13 djh@www0 ~$ sudo yum install php53 php53-mysql php53-gd
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: yum.singlehop.com
 * epel: mirror.steadfast.net
 * extras: mirror.fdcservers.net
 * updates: mirror.sanctuaryhost.com
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package php53.x86_64 0:5.3.3-1.el5_6.1 set to be updated
--> Processing Dependency: php53-cli = 5.3.3-1.el5_6.1 for package: php53
--> Processing Dependency: php53-common = 5.3.3-1.el5_6.1 for package: php53
---> Package php53-gd.x86_64 0:5.3.3-1.el5_6.1 set to be updated
--> Processing Dependency: libXpm.so.4()(64bit) for package: php53-gd
---> Package php53-mysql.x86_64 0:5.3.3-1.el5_6.1 set to be updated
--> Processing Dependency: php53-pdo for package: php53-mysql
--> Running transaction check
---> Package libXpm.x86_64 0:3.5.5-3 set to be updated
---> Package php53-cli.x86_64 0:5.3.3-1.el5_6.1 set to be updated
---> Package php53-common.x86_64 0:5.3.3-1.el5_6.1 set to be updated
---> Package php53-pdo.x86_64 0:5.3.3-1.el5_6.1 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package             Arch          Version                 Repository      Size
================================================================================
Installing:
 php53               x86_64        5.3.3-1.el5_6.1         updates        1.3 M
 php53-gd            x86_64        5.3.3-1.el5_6.1         updates        109 k
 php53-mysql         x86_64        5.3.3-1.el5_6.1         updates         92 k
Installing for dependencies:
 libXpm              x86_64        3.5.5-3                 base            44 k
 php53-cli           x86_64        5.3.3-1.el5_6.1         updates        2.4 M
 php53-common        x86_64        5.3.3-1.el5_6.1         updates        605 k
 php53-pdo           x86_64        5.3.3-1.el5_6.1         updates         67 k

Transaction Summary
================================================================================
Install       7 Package(s)
Upgrade       0 Package(s)

Total download size: 4.6 M
Is this ok [y/N]: y
Downloading Packages:
(1/7): libXpm-3.5.5-3.x86_64.rpm                         |  44 kB     00:00     
(2/7): php53-pdo-5.3.3-1.el5_6.1.x86_64.rpm              |  67 kB     00:00     
(3/7): php53-mysql-5.3.3-1.el5_6.1.x86_64.rpm            |  92 kB     00:00     
(4/7): php53-gd-5.3.3-1.el5_6.1.x86_64.rpm               | 109 kB     00:00     
(5/7): php53-common-5.3.3-1.el5_6.1.x86_64.rpm           | 605 kB     00:00     
(6/7): php53-5.3.3-1.el5_6.1.x86_64.rpm                  | 1.3 MB     00:00     
(7/7): php53-cli-5.3.3-1.el5_6.1.x86_64.rpm              | 2.4 MB     00:00     
--------------------------------------------------------------------------------
Total                                            12 MB/s | 4.6 MB     00:00     
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing     : php53-common                                             1/7 
  Installing     : php53-pdo                                                2/7 
  Installing     : php53-cli                                                3/7 
  Installing     : libXpm                                                   4/7 
  Installing     : php53                                                    5/7 
  Installing     : php53-mysql                                              6/7 
  Installing     : php53-gd                                                 7/7 

Installed:
  php53.x86_64 0:5.3.3-1.el5_6.1           php53-gd.x86_64 0:5.3.3-1.el5_6.1    
  php53-mysql.x86_64 0:5.3.3-1.el5_6.1    

Dependency Installed:
  libXpm.x86_64 0:3.5.5-3                  php53-cli.x86_64 0:5.3.3-1.el5_6.1   
  php53-common.x86_64 0:5.3.3-1.el5_6.1    php53-pdo.x86_64 0:5.3.3-1.el5_6.1   

Complete!
0-13:14 djh@www0 ~$ sudo service httpd start
Starting httpd:                                            [  OK  ]

And now I have successfully upgraded via the web UI.

Most days, I am not a CentOS admin, so if there is a better way to have done this, I am keen to hear.

8 Comments


Linux, Technical

isatapd: IPv6 on Ubuntu

Link: https://dannyman.toldme.com/2011/06/08/can-haz-ipv6/

Yes, it looks like you're using IPv6 already.

SysAdmins, check with Tom.

My employer (Cisco) makes IPv6 available internally on a test basis. Once I configured the isatap hostname on my system, all I had to do to get my Ubuntu laptop on IPv6 was:

sudo apt-get install isatapd

I look forward to trying this on a few more systems:

sudo apt-get install isatapd && ping6 -c 1 www.ipv6.cisco.com && figlet -c 'I CAN HAZ IPv6!!'

Feedback Welcome


Linux, Technical

Amazon.com MP3 Downloader on 64-bit Ubuntu

Link: https://dannyman.toldme.com/2011/03/15/amazon-com-mp3-downloader-ubuntu/

I’ll give Amazon.com credit for making their mp3 downloader available to Linux users:

I clicked on Ubuntu, and Chrome downloaded amazonmp3.deb and the Ubuntu Software Center fired up and told me:

Wrong architecture ‘i386’

That was frustrating. I sent a note to Amazon.com thanking them for their Linux support and asking them to please consider rolling some x86_64 packages. Then I asked Google for advice, and got this fine post:

http://www.ensode.net/roller/dheffelfinger/entry/installing_amazon_mp3_downloader_under

Works fine except the download link to getlibs is old and broken, so I figured I can recapitulate the recipe here:

1) Download amazonmp3.deb and then install it manually:

sudo dpkg -i --force-architecture Downloads/amazonmp3.deb

2) Download and install getlibs: (Thanks for the corrected link, bobxnc!)

http://frozenfox.freehostia.com/cappy/getlibs-all.deb

(Your browser should hand the package off to an installer, else you’ll just do something like sudo dpkg -i Downloads/getlibs-all.deb.)

3) Run getlibs!

Looks something like this:

0-13:08 ~$ sudo getlibs /usr/bin/amazonmp3
libglademm-2.4.so.1: libglademm-2.4-1c2a
libgtkmm-2.4.so.1: libgtkmm-2.4-1c2a
libgiomm-2.4.so.1: libglibmm-2.4-1c2a
libgdkmm-2.4.so.1: libgtkmm-2.4-1c2a
libatkmm-1.6.so.1: libgtkmm-2.4-1c2a
libpangomm-1.4.so.1: libpangomm-1.4-1
libcairomm-1.0.so.1: libcairomm-1.0-1
libglibmm-2.4.so.1: libglibmm-2.4-1c2a
No match for libboost_filesystem-gcc42-1_34_1.so.1.34.1
No match for libboost_regex-gcc42-1_34_1.so.1.34.1
No match for libboost_date_time-gcc42-1_34_1.so.1.34.1
No match for libboost_signals-gcc42-1_34_1.so.1.34.1
No match for libboost_iostreams-gcc42-1_34_1.so.1.34.1
No match for libboost_thread-gcc42-mt-1_34_1.so.1.34.1
The following i386 packages will be installed:
libcairomm-1.0-1
libglademm-2.4-1c2a
libglibmm-2.4-1c2a
libgtkmm-2.4-1c2a
libpangomm-1.4-1
Continue [Y/n]? 
Downloading ...
Installing libraries ...

3.1) If, like me, you got “no match for libboost” as above, or you get “amazonmp3: error while loading shared libraries: libboost_filesystem-gcc42-1_34_1.so.1.34.1: cannot open shared object file: No such file or directory” then do this bit:

sudo getlibs -w http://ftp.osuosl.org/pub/ubuntu/pool/universe/b/boost/libboost-date-time1.34.1_1.34.1-16ubuntu1_i386.deb
sudo getlibs -w http://ftp.osuosl.org/pub/ubuntu/pool/universe/b/boost/libboost-filesystem1.34.1_1.34.1-16ubuntu1_i386.deb
sudo getlibs -w http://ftp.osuosl.org/pub/ubuntu/pool/universe/b/boost/libboost-iostreams1.34.1_1.34.1-16ubuntu1_i386.deb
sudo getlibs -w http://ftp.osuosl.org/pub/ubuntu/pool/universe/b/boost/libboost-regex1.34.1_1.34.1-16ubuntu1_i386.deb
sudo getlibs -w http://ftp.osuosl.org/pub/ubuntu/pool/universe/b/boost/libboost-signals1.34.1_1.34.1-16ubuntu1_i386.deb
sudo getlibs -w http://ftp.osuosl.org/pub/ubuntu/pool/universe/b/boost/libboost-thread1.34.1_1.34.1-16ubuntu1_i386.deb
sudo getlibs -w http://ftp.osuosl.org/pub/ubuntu/pool/main/i/icu/libicu40_4.0.1-2ubuntu2_i386.deb

sudo ldconfig

4) Let the music play!

. . .

Q: What is getlibs?
A: “Copyright: 2007; Downloads 32-bit libraries on 32-bit and 64-bit systems. For use with Debian and Ubuntu.”

1 Comment


FreeBSD, Linux, Mac OS X, Technical

Avoiding Concurrent Crons: Easy File Locking!

Link: https://dannyman.toldme.com/2010/09/20/lockf-flock-cron/

Old SysAdmin tip: keep your frequent-but-long-running cron jobs from running concurrently by adding some lightweight file locking to your cron entry. For example, if you have:

* 15 * * * /usr/local/bin/db-backup.sh

On FreeBSD you could use:

* 15 * * * /usr/bin/lockf -t 0 /tmp/db-backup.lock /usr/local/bin/db-backup.sh

Or on Linux:

* 15 * * * /usr/bin/flock -w 0 /tmp/db-backup.lock /usr/local/bin/db-backup.sh

Read up on the lockf or flock man pages before you go putting this in. This can be a bit tricky because these can also be system calls. Try “man 1 lockf” or the like to nail it down to the manual for the user-executable command.

1 Comment


FreeBSD, Linux, Sundry, Technical, WordPress

FAQ: Why is SSH into my server so slow?!

Link: https://dannyman.toldme.com/2010/06/05/fix-your-dns-with-google/

I have run in to this a zillion times. You SSH to a Unix server, type your password, and then wait a minute or two before you get the initial shell prompt, after which everything is reasonably zippy.

The short answer is “probably, something is wrong with DNS . . . your server is trying to look up your client but it can not, so it sits there for a couple of minutes until it times out, and then it lets you in.”

Yesterday I was working with an artist who had a hosting account, and when he got in, I said:

sudo vim /etc/resolv.conf

He admitted that he had just copied the DNS configuration from his previous server. How to fix this? Well, he could check what nameservers are provided by his current hosting company . . . . or, I changed his file to read:

nameserver 8.8.8.8

“What’s that, localhost?”

“It’s Google! Wherever you are, they’ll give you DNS.”

“Cool!!”

“Yes!!”

Feedback Welcome


Linux, Sundry, Technical

HOWTO: Add a Swapfile at Boot

Link: https://dannyman.toldme.com/2010/05/28/ubuntu-linux-add-swap-file-at-boot/

A while back I outfitted my personal workstation with 4GB of RAM. That’s plenty of memory and since disk space was tight I didn’t want to waste any on a swap partition, and I lived happily without swap for a very long time until I began using more virtualization. (I freed up space on my physical desk top by migrating my work environment from a laptop to a virtual machine on my personal workstation.)

I wrote a script to add a “temporary” swap file on demand but what I wanted was a swap file at boot. That actually turns out to be pretty simple. In this case, I just prepare the swap file:

FILE=/mnt/swapfile
SIZE=8388608 # 8 GB

dd if=/dev/zero of=$FILE bs=1024 count=$SIZE
mkswap $FILE $SIZE
swapon $FILE
swapon -s

Then, to make it stick, add this line to /etc/fstab just as you would for a swap partition:

/mnt/swapfile none swap sw 0 0

This is a win for the Unix everything-is-a-file philosophy.

See Also: Ubuntu Community Swap FAQ

3 Comments


Linux, Sundry, Technical, WordPress

Rackspace Cloud Server: Crude Performance Tuning

Link: https://dannyman.toldme.com/2010/05/20/rackspace-cloud-server-crude-performance-tuning/

I recently migrated this web site to a virtual server at the Rackspace Cloud. I started with the cheapest, 256M slice, but after hitting some performance issues really quickly, I figured that the extra $10/month to grow the slice to 512M was worthwhile. Even so, I don’t think MySQL and Apache are tuned, out-of-the-box, for such “small” systems.

I am running WordPress, a PHP application, on Apache and MySQL, running on CentOS. I am using Munin to track the system health. Since MySQL performance tuning can be extremely complicated I have focussed my initial efforts on Apache.

So, the memory graph would ideally top out at 512MB, but in practice, the system and programs allocate excess memory they rarely touch, and that gets paged out to swap. It is when the swap activity gets high that system performance goes to heck. A spike in system load is a good symptom of possible performance issues.


When things went bad on Wednesday, I tuned Apache down somewhat from the defaults and then enabled the Apache status page, and told Munin to go ahead and graph that. I am new to Munin, but Slicehost has some excellent articles on installing and configuring it in my environment.

This morning Munin sent me e-mail that it was having trouble collecting data, so I took a look, and reset performance values for Apache based on the above graph:

<IfModule prefork.c>
StartServers      6
MinSpareServers   3
MaxSpareServers  12
ServerLimit      15
MaxClients       15
MaxRequestsPerChild  4000
</IfModule>

Hopefully, this will hold. I would love to audit the system memory use in greater detail to allow Apache some greater flexibility, but in the interests of achieving a stable system quickly, this will hopefully prove to be a good strategy.

Feedback Welcome


Linux, Technical

Ubuntu: Re-install All Packages

Link: https://dannyman.toldme.com/2010/05/05/ubuntu-reinstall-all-packages/

After some transient disk issues I was stuck with an Ubuntu VMWare image that was brain dead. I figured I would give the install CD a chance to fix but the Ubuntu install CD doesn’t have a fix-it option. (Really?!) Since the issue was somewhere in how Gnome and X were configured, I launched an xterm session and managed this command:

dpkg --get-selections \* | awk '{print $1}' | xargs -l1 aptitude reinstall

What that does is get a list of all packages installed on a system, then invoke “reinstall” for each package. It took a few hours to run.

The Ubuntu forums had a recipe using some more straightforward Debian incantation, but that didn’t work for me.

7 Comments


Linux, Sundry, Technical, Technology

Windows 7 vs Ubuntu 9.10

Link: https://dannyman.toldme.com/2009/12/02/windows-7-ubuntu-first-impression/

So, I tried Windows 7 beta, and recently scored a copy of Windows 7 for my desktop PC, via employee discount. (I’d be willing to pay $50 for the OS, so $25 isn’t a bad deal. The again, Microsoft sent me some very large checks for my Tellme equity in 2007 so a very small Capitalist part of me is rooting for them.)

Where do you want to install Windows?

It is pretty nice: basically a refresh of Windows XP, with extra spit-and-polish. Zippier, too! It boots and shuts down faster than XP or Ubuntu, and manages OS updates without requiring my intervention and subsequently breaking things, like Ubuntu does. I was musing to my coworkers that if it had the following, I could switch from Linux:

1) A decent software packaging system.
2) Built-in Virtual Desktops.
3) Middle-button paste.

Boot/Shutdown Speed

I turn my computers off when I’m not using them. I like that Firefox will remember tab sessions. But waiting for an OS to boot is wasted time.

Despite recent improvements, Ubuntu still takes way too long to boot, and seemingly forever to shut down. Windows 7, by contrast, is pretty darn zippy. I like that!

Winner: Windows 7

System Updates

So, for the record, I’m thinking to turn off system updates on my Ubuntu environments, because they aren’t worth it and they keep breaking my stuff. I’ll just refresh twice a year when the new release comes out, therefor managing the pain of upgrades. Windows updates are more important, given the constant security threats. Fortunately, Windows does that for me without my noticing, save the stupid “I will forcibly reboot you in 5 minutes” thing that hasn’t hit me (yet?) on Windows 7.

Winner: Windows 7

Software Packaging

Windows seems to have made some improvements with software packaging, and I gotta say it is convenient to go to a web site, click on an installer, and a few minutes later have the application running. Of course, then there’s another icon on your desktop and the Yahoo! tool bar has been added to your web browser . . .

On Ubuntu, though, most of the time I go to a shell and type:

sudo aptitude install foo

And there I go!

Sometimes software isn’t available in the central repositories, but 9.10 has made adding some PPAs easier. And sometimes I go to a web site, click on a link to a .deb file, it downloads, the system asks for my password, and the software gets installed without leaving crappy toolbars in my environment. Victory!

Winner: Ubuntu

Virtual Desktops

Ubuntu’s Gnome interface would be nicer if I could drag windows to the side of the screen and they’d pop over to the next screen, like the fvwm2 pager. But, I’m pretty well content with Ubuntu’s virtual desktop ability.

You could probably install a decent hack on Windows 7 to get this, but really, virtual desktops and pagers should be built in.

Winner: Ubuntu

Command Line Environment

So, with Ubuntu I can fire off command shells with wild abandon and do what I need to do. (I’m a Unix system administrator, so I relate to computers mostly by typing commands and scripting.) Windows 7 has a new “PowerShell” feature that implements a few Unix commands. After half an hour of searching I discovered that you can get to the PowerShell by hitting Windows+R and then typing “powershell” — heck forbid we should put this in the start menu or make it available by searching for “shell” but okay . . .

With Ubuntu, I can highlight text by dragging and clicking my mouse. This is just like other environments, but instead of hitting control-C (or, ahem Open-Apple-C) to copy the highlighted text into your clipboard, and control-V (I mean, Command-V) to paste from your clipboard, with Unix, whatever you highlight goes straight to the clipboard, and you paste by tapping the middle mouse button.

That can be a little scary sometimes but once you get used to the convenience you really can’t go back to having to mouse and keyboard to cut and paste.

Once you figure out how to launch the PowerShell, you can not simply highlight text with the mouse. Seriously, WTF!? No, this is how you copy-and-paste stuff with PowerShell:

Hit Alt+Space to bring up the console menu, then type ‘E’ to bring up the ‘Edit’ menu and then ‘k’ to start copying or ‘P’ to paste the text in the clipboard to the console. In ‘copying’ mode, you just use the arrow keys while holding down the shift key to select text, and hit Enter to add the selection to the clipboard.

Durr
“Ah, hello, Microsoft? Yes, the 1980s called and they want their primitive user interface back. Thanks!”

Update: You can launch PowerShell is a window that supports text highlighting by dragging the mouse via Start > All Programs > Windows PowerShell > Windows PowerShell. It looks like you can copy highlighted text with control+C and paste with the right mouse button. (Getting closer, I guess!)

Winner: Ubuntu

Focus Follow Mouse

Down in the accessibility menu, there’s an option for “Activate a window by hovering over it with a mouse” . . . but checking that option doesn’t actually change the behavior . . .

. . . correction: it does. After some seconds it brings the window you are hovering over to front. No, I just want focus, not raise! Arrr! Ubuntu knows how to do this, with just a little checkbox.

Update: There are three ways to do this. The registry hack was my solution.

Winner: Ubuntu

Default Web Browser

I’ll give Internet Explorer some credit; I can type whatever crazy thing I want into the URL bar and the second it realizes I didn’t type a URL, it goes over to Bing. Nice!

But then the default behavior is to create new windows all over. Seriously: what is the point of tabbed browsing if you don’t put stuff in the tabs? The big fail though is that for whatever reason the WordPress HTML editor in Explorer keeps jumping up to the top of the text input window, which made working out this post a seriously annoying experience.

A quick install of Google Chrome and my web browsing experience not only interfaces well with WordPress and pops new windows into tabs, but I can type whatever crazy stuff I want into the URL bar and in a not-be-evil sort of way, it shunts me with due humility over to Bing. So, Chrome is my new default web browser for Windows 7. (And I’ll continue trying out Bing, even though I’m a Google fan-boy.)

Winner: Ubuntu

7 Comments


Linux

HOWTO: Ubuntu Support for Audio in XVidCap

Link: https://dannyman.toldme.com/2009/09/28/howto-ubuntu-xvidcap-audio-support/

XVidCap is a very nice screen-capture program for Linux.  I have been dabbling in it to capture video of my desktop.

Unfortunately, the binary offered by Ubuntu’s software distribution has audio disabled. I found a bug about that somewhere and added my two cents, then went and installed it manually. Then I had to reinstall it manually because the Ubuntu version had been bumped and the “newer” version replaced my audio-supporting version.

Step 1: Remove Existing xvidcap

sudo aptitude remove xvidcap

Step 2: Install XVidCap from SourceForge

http://sourceforge.net/projects/xvidcap/ — click “download now” and the rest is all point-and-click.

Step 3: Lock XVidCap Version

Ubuntu will be quietly bide its time until it can “upgrade” xvidcap to a version that doesn’t support Audio. Fortunately, you can tell it not to do that!

Open: System > Administration > Synaptic Package Manager

Search for “xvidcap”

Select the package, go to the Package menu and select “Lock Version”

(From what I can tell, sudo aptitude hold won’t actually prevent xvidcap from being “upgraded.”)

14 Comments

« Newer Stuff . . . Older Stuff »
Site Archive