Klaus Knopper answers your Linux questions

Ask Klaus

Article from Issue 163/2014
Author(s):

Klaus solves problems with slow boots, Windows print shares, device detection, and clock synchronization.

Lin Hearts Win?

Dear Klaus: Thank you for the explicit answers. I am waiting to read your answers in every magazine.

My Asus K53SV laptop behaves strangely. SUSE Linux 12.3 boots in 13 seconds after restart from Windows 7, always, but it takes 27 seconds after a direct boot. Restarting Linux after Linux does not speed up the boot time. Maybe Linux has warm feelings for Windows?

Both OSs are 64 bit. The bootloader is GRUB. Original HDD was replaced with SSD – Mushkin Chronos 480GB. BIOS is American Megatrends v.320. Do you see a way to make Linux boot directly in 13 seconds?

Best regards, Jukka

Answer: I have seen this happening when working with Realtek network cards that need special firmware in order to operate at full speed. When Linux loads the network cards module, it waits for a firmware file to be transferred to the card. If this does not happen, a timeout occurs and the card operates in a working, but somewhat "degraded" mode with less efficient bandwidth use from its internal firmware. It may be these additional 10 seconds of timeout waiting for firmware to appear that delays the boot process in the case of a "cold boot."

But booting Windows, having been installed with the appropriate drivers, may already have uploaded the accelerated firmware. After a warm start without power loss, the network card is activated immediately by Linux and the driver will not ask for additional firmware.

The same may be the case with other devices that ask for binary firmware files.

You can check your logs for an entry that says requesting firmware or similar, to find out the name of the file you need. Most binary firmware is included in the linux-firmware package in Debian and Ubuntu; the firmware for Realtek network cards is included in firmware-realtek, so it may be that the boot process speeds up after installing those packages on your system. However, if the device in question is activated during the early boot phase in the initial ramdisk, you may also have to copy the firmware into /lib/firmware inside the initrd to take advantage of it.

There is another option: If you can identify the boot script that causes the delay, you could reassign it after the regular desktop startup, where a delay because of missing firmware would not matter that much.

Windows Print Share

Hi Klaus: I am running Knoppix 7.2 installed on the hard drive of a 1GB (RAM) laptop. Everything is fine, but I cannot get the printer setup to find/connect a Windows print share. The Browse option is simply greyed out. I am able to access Windows shares on the same machine as the printer via Konqueror without any problem.

Please advise. Thanks, Neil

Answer: Knoppix does not run any client-side NetBIOS discovery services because of security and performance reasons, so programs have to send a network broadcast for print services on their own.

The CUPS server is currently also set up to avoid too much network traffic, so the greyed out button just means that the option of scanning the network for printers shared over SMB is simply not available. I may reconsider this option in future versions.

Possible solutions:

  1. Open a shell, run the command

    sudo cupsctl 'BrowseLocalProtocols="cups dnssd lpd smb"'

(watch out for the correct quoting here) to allow scanning SMB network services for printers from CUPS configuration website http://localhost:631 in this session.

  1. Shut down CUPS with

    sudo /etc/init.d/cups stop

Edit /etc/cups/cupsd.conf and add smb to the BrowseLocalProtocols directive, then restart CUPS with

sudo /etc/init.d/cups start

and retry automatic network printer detection.

  1. Add a windows printer manually by entering the URI

    smb://username:password@workgroup/server/printer_name

in the CUPS "add printer" configuration GUI, which, if the printer does not require a login, can be shortened to smb:/server/printer_name.

Device Detection

Hi Klaus: I got [Knoppix] version 7.3 CeBIT Edition with issue 161 of Linux Magazine, and I read your article about creating a flash boot medium. After I chose Allow installation only on removable devices, I got an error message to the effect that my flash drive (a SanDisk Cruzer Facet, 8GB) was not detected. When I opened the file manager the flash drive was mounted.

However, when I tried version 7.2 from issue 154, it worked like a charm. Is there an issue with device detection in version 7.3?

Regards, Con

Answer: There should be no issue detecting flash drives in general, however, Knoppix 7.3 has a new option to only show "removable devices" in the list, meaning devices that have a flag set that identifies them as being "detachable," as opposed to a standard USB hard drive. Now, even during CeBIT, I met some flash drives that have this flag unset, meaning they only show up in the list when you select Allow installation also on fixed hard disks. Otherwise, flash-knoppix will just skip those devices that, incorrectly or not, identify themselves as a fixed hard disk.

Linux makes no difference in handling USB media, whether it is a hard disk, a digital camera, a smartphone external SD card connected via USB cable, or a flash pen drive. If the device is not listed under the "removable device" section, it may help to try the "fixed disk" setting to find it.

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