Hdparm: differenze tra le versioni

=Cosa serve=

==Installazione==

<pre>

# apt-get install hdparm

==Kernel==

* avere i moduli per il proprio chipset caricati (o compilati staticamente nel kernel)

=Opzioni e Argomenti=

; -a : Get/set sector count for filesystem read-ahead. This is used to improve performance in sequential reads of large files, by  prefetching  additional blocks  in  anticipation  of  them being needed by the running task.  In the current kernel version (2.0.10) this has a default setting of 8 sectors (4KB).  This value seems good for most purposes, but in a system where most file accesses are random seeks, a smaller setting might  provide  better performance.  Also, many IDE drives also have a separate built-in read-ahead function, which alleviates the need for a filesystem read-ahead in many situations.

:; 0 : per disabilitare il supporto a 32-bit

:; 1 : per abilitare il trasferimento dei dati a 32-bit

; -C : Controlla lo stato corrente dell'alimentazione del dispositivo; le possibili risposte sono:

:; unknown : il dispositivo non supporta la funzione

:; active/idle : stato normale

; -D : Enable/disable the on-drive defect management feature, whereby the drive firmware tries to automatically manage defective sectors by relocating them to "spare" sectors reserved by the factory for such.

; -f : Sincronizza ed esegue un flush del buffer del dispositibo. Viene eseguito anche dutante i test '''-T''' e '''-t'''

; -g : Mostra la geometria del drive (cilindri, testine, settori), la dimensione (in settori) del device, e l'offset di partenza (in settori) del device dall'inizio del drive.

;-i : Display the identification info that was obtained from the drive at boot time, if available.  This is a feature of modern IDE drives, and may not be supported by older devices.  The data returned may or may not be current, depending on activity since booting the system.  However, the current multiple sector mode count is always shown.  For a more detailed interpretation of the identification info, refer to AT Attachment Interface for Disk Drives (ANSI ASC X3T9.2 working draft, revision 4a, April 19/93).

; -Istdin : This is a special "no seatbelts" variation on the -I option, which accepts a drive identification  block  as  standard  input  instead  of  using  a /dev/hd*  parameter. The  format of this block must be exactly the same as that found in the /proc/ide/*/hd*/identify "files", or that produced by the '''-Istdout''' option described below.  This variation is designed for use with collected "libraries" of drive  identification  information,  and  can also be used on ATAPI drives which may give media errors with the standard mechanism.

; -Istdout : This  option  simply  dumps the identify data in hex to stdout, in a format similar to that from /proc/, and suitable for later use with the -Istdin option.

; -q : Handle  the next flag quietly, suppressing normal output.  This is useful for reducing screen clutter when running from system startup scripts.  Not applicable to the -i or -v or -t or -T flags.

; -Q : Set tagged queue depth (1 or greater), or turn tagged queuing off (0).  This only works with the newer 2.5.xx (or later) kernels, and only with  the few drives that currently support it.

; -R : Register an IDE interface.  Dangerous.  See the -U option for more information.

:; 1-240 : specifica i multipli di 5 secondi, gestendo un timeout variabile tra i 5 secondi e i 20 minuti

:; 252 : 21 minutes

:; 253 : imposta un timeout preimpostato dal produttore, variabile tra le 8 e le 12 ore

; -W : Disable/enable the IDE drive's write-caching feature (default state is undeterminable; manufacturer/model specific).

; -X :    Set  the  IDE transfer mode for newer (E)IDE/ATA drives.  This is typically used in combination with -d1 when enabling DMA to/from a drive on a sup ported interface chipset, where -X mdma2 is used to select multiword DMA mode2 transfers and -X sdma1 is used to select simple mode 1 DMA transfers. With  systems  which  support  UltraDMA  burst  timings, -X udma2 is used to select UltraDMA mode2 transfers (you'll need to prepare the chipset for UltraDMA beforehand).  Apart from that, use of this flag is seldom necessary since most/all modern IDE drives default to their fastest PIO  transfer mode  at  power-on.  Fiddling with this can be both needless and risky.  On drives which support alternate transfer modes, -X can be used to switch the mode of the drive only.  Prior to changing the transfer mode, the IDE interface should be jumpered or programmed (see -p flag) for the new  mode setting  to  prevent  loss  and/or corruption of data.  Use this with extreme caution!  For the PIO (Programmed Input/Output) transfer modes used by Linux, this value is simply the desired PIO mode number plus 8.  Thus, a value of 09 sets PIO mode1, 10 enables PIO mode2, and 11 selects PIO mode3. Setting  00  restores  the drive's "default" PIO mode, and 01 disables IORDY.  For multiword DMA, the value used is the desired DMA mode number plus 32.  for UltraDMA, the value is the desired UltraDMA mode number plus 64.

:** '''0''' -X08 3.3MB/sec

:** '''1''' -X09 5.2MB/sec

:** '''3''' -X11 11.1MB/sec

:** '''4''' -X12 16.7MB/sec  

:** '''0''' 2.1MB/sec

:** '''1''' 4.2MB/sec

:** '''2''' 8.3MB/sec  

:** '''0''' -X32 4.2MB/sec

:** '''1''' -X33 13.3MB/sec

:** '''2''' -X34 16.6MB/sec  

:** '''0''' 16MB/sec

:** '''1''' 25MB/sec

:** '''4''' -X68 66MB/sec UDMA66

:** '''5''' -x69 100MB/sec UDMA100  

; -z : Forza la rilettura della tabella delle partizioni, utile nel caso di modifiche con ''fdisk'' o simili, senza rendere necessario un riavvio della macchina.