LPI Linux Certification in a Nutshell, 2nd Edition

Objective 3: Software and Kernel Configuration

In the Level 1 Exams, you were prepared to compile kernels and install software to be used with your hardware, including using various hardware-specific tools. For this objective, you are expected to use these tools and kernel options for special hard drive applications, such as Logical Volume Manager (LVM).

hdparm

This command can find a lot of information about your hard drives beyond the more familiar fdisk output. Specifically, hdparm can provide this type of information:

# hdparm /dev/hda

/dev/hda:
 multcount    = 16 (on)
 IO_support   =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    =  8 (on)
 geometry     = 9729/255/63, sectors = 156301488, start = 0
# hdparm -i /dev/hda

/dev/hda:

 Model=ST380013AS, FwRev=3.05, SerialNo=3JV2WAWB
 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
 BuffType=unknown, BuffSize=8192kB, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=156301488
 IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4
 DMA modes:  mdma0 mdma1 mdma2
 UDMA modes: udma0 udma1 *udma2
 AdvancedPM=no WriteCache=enabled
 Drive conforms to: ATA/ATAPI-6 T13 1410D revision 2:

 * signifies the current active mode

All this can be useful to troubleshoot and/or tune IDE disks. The most important thing for I/O performance is not to use PIO ...