dolejsky.com » Bits and pieces

Western Digital HDD spin down problem in Mac OS 10.6

ludek — Sat, 01 Jan 2011 12:11:54 +0000

I've bought brand new Western Digital Scorpio Blue 750 GB SATA HDD for my MacBook laptop (as my secondary hard drive). It's currently the maximum capacity you can get for standard height (9 mm), the 1000 GB model is taller and wouldn't fit into my OptiBay which I use instead of CD drive.

There is one annoying issue with this drive in Mac OS and that is its aggressive power management which spin downs the drive immediately after last application stops accessing it. Not only causes this clicking sound every few seconds and excessive wear (spin up/down cycle count is limited), but also performance is really crappy, as application accessing the drive after spin down has to wait for drive to spin up again.

To deal with this problem, you have to set APM value of the drive to higher value (as described here):

0	Reserved
1	Minimum power consumption with Standby
2 - 127	Intermediate power management levels with Standby
128	Minimum power consumption without Standby
129 - 253	Intermediate power management levels without Standby
254	Maximum performance
255	Reserved

To observe Load_Cycle_Count and Start_Stop_Count parameters of the drive, I've used smartctl:

./smartctl disk1 -a | grep -e "Load_Cycle_Count" -e "Start_Stop_Count"

To set APM value, I've used hdapm:

./hdapm disk1 128
disk1: WDC WD7500BPVT-22HXZT1
Setting APM level to 0x80: Success

After experimenting a little bit I found the following:

value 254 seems to mean no head parking (Load_Cycle_Count doesn't increase) and no spin down at all (Start_Stop_Count doesn't increase when MacBook is up and running)
Value 128 (possibly 128 - 253) seems to allow head parking approx. 2.5 secs after last disk access (Load_Cycle_Count increases and click can be heard) but no spin down is allowed. Drive still seems to slow down a little bit after some time, but it doesn't seem to do a complete start/stop cycle as Start_Stop_Count doesn't increase
Value 127 seems to allow heads to be parked quite often and spin down is allowed - drive seems to wait approx. 25 seconds after last access before complete spin down)

Now, the decision between 128 (don't allow spin down) and 127 (allow spin down) is up to everyone's preferences. Googling a bit revealed that modern laptop drives can do somewhere about 600,000 load cycles and 50,000 start/stop cycles.

To make sure APM value is set after every reboot, you can place hdapm.plist under /Library/LaunchAgents as described in documentation. I'm using the following script:

PLAIN TEXT

XML:

<?xml version="1.0" encoding="UTF-8"?>
"-//Apple Computer//DTD PLIST 1.0//EN" "
http://www.apple.com/DTDs/PropertyList-1.0.dtd">
version="1.0">
>
>Label>
>hdapm>
>ProgramArguments>
>
>/usr/bin/hdapm>
>disk1>
>128>
>
>RunAtLoad>
/>
>
>

iOpravna & Apple rulez!

ludek — Wed, 16 Jun 2010 06:00:35 +0000

After 1.5 years my Macbook battery capacity dropped suddenly (only after about 130 cycles). I've contacted iOpravna.cz to ask whether it would be possible to get the battery replaced under my 3 year NBD warranty and they've sent technician to test the battery (at my place).

Result is positive: I've got new battery (for free) that allows me to work 4 hours again!

Good job!

Java – print stack trace to a String

ludek — Thu, 25 Feb 2010 18:54:10 +0000

Simple and quick one today - what if we need to print stack trace into a String?

PLAIN TEXT

JAVA:

...
catch (Exception e) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
e.printStackTrace(pw);
pw.flush();
String stackTraceString = sw.toString();
//use the stackTraceString as you need...
}
...

Remote Mic now supports both Mac OS and MS Windows!

ludek — Thu, 19 Nov 2009 12:00:07 +0000

Remote Mix is application that turns your iPhone into a wireless microphone (or a bug).

Today, Remote Mic Console 1.3 has been released for both Mac OS 1.5.x and MS Windows XP.

More information here

GrowlTunes patch accepted

ludek — Tue, 10 Nov 2009 11:08:40 +0000

My small GrowlTunes patch (described here) made its way into official release of Growl 1.1.5:

I am happy to have contributed to such a great piece of an open source software.

GrowlTunes 1.1.4 patch

ludek — Thu, 19 Feb 2009 10:31:15 +0000

I use and love Growl! and especially the GrowlTunes plugin which shows you track info when iTunes song changes.

What really annoys me, though - when listening to radio stream, it shows "(null)." instead of track number and there is also only radio name, not song name in the recently played songs menu.

I created small patch. Or download patched binary. Simply unpack and put into your Applications folder (replacing original GrowlTunes if present).

This is how it looked before:

And this is how it looks like after patch:

Quick ‘n’ dirty – manipulate GIF in Java

ludek — Tue, 11 Mar 2008 21:35:55 +0000

I needed to directly modify pixel values of several images in a special way. First, I looked into Gimp's Script-Fu functionality, but this seemed too complicated for what I needed so I decided to write such one-off utility in Java.

It simply reads all GIF images in specified directory, does some custom transformation of pixels, and then writes images back onto disk. It is really quick'n'dirty so be warned

Source code: ImageManipulation.java

Tweaking XOM parser – element position support

ludek — Tue, 22 Jan 2008 09:49:50 +0000

XOM parser is a great piece of code. I was missing just one feature - to be able to get position of element in source file (line and column). So I did a quick and dirty hack resulting in two new nu.xom.Element methods: getLineNumber() and getColumnNumber().

Works nice when used in conjunction with org.apache.xerces.parsers.SAXParser (but wasn't tested with anything else so take care...).

If you're interested, download the original xom-1.1.zip file, unpack and unpack all files from my xom-1.1.position.patch.zip over original ones.

Serious new Google Analytics security problem

ludek — Thu, 17 May 2007 22:14:33 +0000

I ran into a really disturbing security incident in the new Google Analytics interface today. A friend of mine was making me able to see the stats of upcoming accommodation website www.aboveeurope.com and an error occurred during the operation. What a surprise for me it was when I could see the statistics of totally foreign website in my analytics account afterwards!

I contacted Google immediately and will post any new facts here.

See the screenshot of my Analytics account with the stats of website I shouldn't be allowed to see (I don't know that corporation nor I am in any way affiliated with it):

(click to see full image)

openSuse 10.2 on Lenovo 3000 n100

ludek — Tue, 09 Jan 2007 09:55:38 +0000

Installing openSuse 10.2 on Lenovo 3000 n100.

When choosing installation type, it's necessary to use "maxcpus=0" kernel parameter, otherwise kernel hangs - probably a bug (#231205, #227279).

Hardware

Beware of Wifi hardware switch! When switched OFF, system hangs at boot-time when detecting WiFi card.

For correct 1280x800 display resolution (even after hibernate) set VIDEOBIOS_PATCH="yes" and VIDEOBIOS_PARAMETERS="5a 1280 800 32" in /etc/sysconfig/videobios.

Sound card stopped working after every volume change. Adding "model=3stack" parameter helped. Volume up/down buttons ceased to work after keyboard layout change, didn't try to solve it yet.

No problems with Ethernet or WiFi. There is no support for Web camera yet.

Software

Firefox wasn't able to resolve hostnames. Turning off IPv6 in Firefox (about:config, network.dns.disableIPv6=true) helped. Maybe it is just problem with our router.

Amarok cannot play mp3, you have to uninstall xine-lib and install it again from Packman repository. Everything works fine, then.

Tuning

Enabling Eclipse's Ctrl+F11 shortcut
Eclipse's Ctrl+F11 shortcut (Run last launched) didn't work in KDE because it is defined as KDE shortcut (Switch to Desktop 11). Removing this association helped.

Remapping PrtSc to Home and Pause to End:
1. Change following lines in /usr/share/X11/xkb/symbols/pc:
key { [ Home ] };
key { [ Scroll_Lock ] };

2. Make following change in file /~/.kde/share/config/khotkeysrc:

[Data_3_9]
Comment=Launches KSnapShot when PrintScrn is pressed.\n
Enabled=false
Name=PrintScreen
Type=COMMAND_URL_SHORTCUT_ACTION_DATA