topic Re: raw device in Operating System - HP-UX

raw device

luigi coco — Mon, 08 Mar 2004 07:08:00 GMT

Hi !!
how I can determinate the percentage used by a raw device ??
Is there a command like "bdf" for raw devices ???

Thanks

Re: raw device

Mark Grant — Mon, 08 Mar 2004 07:16:22 GMT

raw devices are not handled by the operating system and therefore there are no tools as such. THere is no way HPUX could know if all the empty space at the end of your applications data is in fact empty or reserved by the application or even just the kind of data you like to write to disk.

Re: raw device

Karthik S S — Mon, 08 Mar 2004 07:16:27 GMT

No .. there are no commands available to determine that. ..

-Karthik S S

Re: raw device

Mobeen_1 — Mon, 08 Mar 2004 07:51:25 GMT

Luigi,
Unfortunately these raw devices are not handled by the OS. These devices are taken care by the application (mostly dB apps)

rgds
Mobeen

Re: raw device

Trond Haugen — Mon, 08 Mar 2004 07:56:57 GMT

From HP-UX point of view the raw (disk) devices just exist. The "format" of the raw device is only known to the appication using it. Thus there is no command in HP-UX that can tell you how much is used. The application however may have it.

Regards,
Trond

Re: raw device

Geoff Wild — Mon, 08 Mar 2004 08:37:36 GMT

No, you can't tell - nor do you want to.

A raw device, also known as a raw partition, is a disk partition that is not mounted and written to via the UNIX filesystem, but is accessed via a character-special device driver; it is up to the application how the data is written, since there is no filesystem to do this on the application's behalf.

For Oracle, You should specify a tablespace slightly smaller in size than the raw partition size, specifically at least two Oracle block sizes smaller.

Rgds...Geoff

Re: raw device

Ravi_8 — Mon, 08 Mar 2004 09:13:44 GMT

Hi,

there is no any command exist to show usage of raw devices in hp-ux