LPI exam 101 prep: Hardware and architecture

В рамках подготовки к сдаче экзамена 101 уровня Junior Level Linux Professional LPIC-1 публикую краткие описания команд и фактов из подготовительных материалов IBM к этому экзамену.

Hardware and architecture - topic 101

/proc filesystem. This is not a real filesystem on disk, but a "pseudo file system"

/proc/pci contains information about the devices on the system's PCI bus

lspci command gives similar information

/proc/ioports tells us about the IO ports available on the system

information on interrupts is also kept in the /proc file system, in /proc/interrupts

dmesg command to look for bootstrap messages

DMA channels are in use - in /proc/dma.

lspnp command (part of the kernel-pcmcia-cs package) to display information about PnP devices. File /proc/bus/pnp will contain this information.

hdparm -I /dev/hda

Even without the artificial limits of BIOS or DOS, the CHS design allows for up to 65536 cylinders, 16 heads, and 255 sectors/track. This limits the capacity to 267386880 sectors, or approximately 137 GB.

Devices that start with /dev/hd, such as /dev/hda or /dev/hda5 refer to IDE drives.
The first drive on the first IDE controller is /dev/hda and the second one, if present, is
/dev/hdb. Likewise, the first drive on the second IDE controller is /dev/hdc and the
second one is /dev/hdd.

Today, you will find that both USB and SATA storage devices appear as sd, rather
than hd, devices.

network configuration tool such as system-config-network in Fedora Core 4.

lsmod command will format the contents of /proc/modules and display the status of loaded modules

If you want to know which real device corresponds to say /dev/sda, you can use the
scsi_info command.

sg_map command will provide a map between the sg name and another device name if one exists.

sginfo command interrogates the device for the information while the scsi_info will use the retained information.

The file /proc/bus/usb/devices contains summary information for currently attached USB devices.

lsusb command to help you with display of USB information. In particular, you can get a tree view of your USB devices by using the -t option. This shows their attachment hierarchy. You can use the -d option for information about a specific device if your system gives an abbreviated display using the -t option. The -v option produces verbose output which interprets many of the fields.