[Bug 548513] Re: Some firewire & usb disks not working under 10.04

[Peter Petrakis]

So this is failing for me too, the device is being offlined.

It would help to know what hdparm is actually doing, this is on 10.4 on
my T510:

<10:30:50>udev$ diff -u hdparm.orig hdparm
--- hdparm.orig	2010-04-14 10:26:37.233760588 -0400
+++ hdparm	2010-04-14 10:27:40.262576808 -0400
@@ -27,6 +27,7 @@
 
 OPTIONS=$(hdparm_options $DEVNAME)
 if [ -n "$OPTIONS" ]; then
+	/usr/bin/logger -p info "Executing hdparm with options $OPTIONS on $DEVNAME"
 	/sbin/hdparm $OPTIONS $DEVNAME 2>/dev/null
 fi

<10:27:40>udev$ tail -f /var/log/messages | grep hdparm


Apr 14 10:28:08 nautilus logger: Executing hdparm with options -B254 on /dev/sdc

According to the hdparm manpage, -B configures power management:

"... The highest degree of power management is attained with a setting
of 1, and the highest I/O performance with a setting of 254.   A  value
of  255 tells  hdparm to disable Advanced Power Management altogether on
the drive (not all drives support disabling it, but most do)"

This value is being determined by /lib/hdparm/hdparm-functions ...

    egrep -v '^[[:space:]]*(#|$)' /etc/hdparm.conf |
    {
        # set our default global apm policy here.
        if hdparm_is_on_battery; then
            hdparm_set_option -B128
        else
            hdparm_set_option -B254
        fi

So you might get different results depending on whether your laptop is
on ac power or not.

It looks like we could completely work around this by adjusting the
defaults in /etc/hdparm.conf.

We'll see how this behavior is different from 9.10.

-- 
Some firewire & usb disks not working under 10.04
https://bugs.launchpad.net/bugs/548513
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