topic Re: finding IDE SCSI disks in Operating System - Linux

finding IDE SCSI disks

Jagadesh — Fri, 10 Oct 2003 10:01:04 GMT

Is there any command to display the IDE and scsi HD seperately.

Iam aware that
#fdisk -l
will display both scsi and IDE harddisk but the same is displaying all the partitions too.

Is there a seperate command to display on harddisk and not the partitions (with out using grep)

Thanks
Jagadesh

Re: finding IDE SCSI disks

Alexander Chuzhoy — Fri, 10 Oct 2003 10:22:54 GMT

try man on "hdparm" utility (i'm currently not on Linux OS otherwise the I would be more specific

Re: finding IDE SCSI disks

Huc_1 — Fri, 10 Oct 2003 11:56:02 GMT

For scsi
As root
#cdrecord -scanbus
or
# cat /proc/scsi/scsi

For ide
As root
#for i in a b c d ; do hdparm -I /dev/hd$i ;done

only put in the require in a b c d (ex: only a if you have only hda drive)

hdparam --help
reveals a lot of options so you can tailor the above to suite your needs.

J-P

Re: finding IDE SCSI disks

Jagadesh — Sat, 11 Oct 2003 02:47:45 GMT

Is there a command to list only the attached scsi or ide disks (apart from fdisk command)?

Re: finding IDE SCSI disks

Huc_1 — Sat, 11 Oct 2003 03:24:46 GMT

Not that I know !

The best I can think is to make a sript do what you want

J-P

Re: finding IDE SCSI disks

Mark Grant — Sat, 11 Oct 2003 07:54:15 GMT

"dmesg | grep disk" or something like that might work for a while.

Re: finding IDE SCSI disks

Stuart Browne — Sun, 12 Oct 2003 19:38:24 GMT

If it's a redhat system, you might find something similar to this useful:

grep "^[hs]d[a-zA-Z]" /var/log/dmesg

The 'dmesg' command that Mark mentioned is available on all Linux distributions, however it's a circular buffer of which can only hold a few kb of data (16 by default). RH, by default, dumps this out right after boot-up so the boot messages get recorded successfully, and not lost when the buffer fills up.

This will only find standard drives, not those based upon some of the more advanced controllers (I'm unaware of how fibre-channel based controllers device out their nodes, and the SmartArray use /dev/cciss/ nodes).

Hopefully this will give you a start.

As far as I'm aware however, there is no tool that will successfully list all drives, as I know 'fdisk' does not ('sfdisk -l' comes close though).

Re: finding IDE SCSI disks

Mark Grant — Mon, 13 Oct 2003 01:29:23 GMT

There must be a better way of doing this because "vgscan" does it. I wonder if /proc is the answer here.

Re: finding IDE SCSI disks

Stuart Browne — Mon, 13 Oct 2003 03:45:29 GMT

For SCSI drives, yes. /proc/scsi/scsi will list such devices.

There is no equivalent however for IDE devices. As far as I'm aware, they are found and maintained at bootup, spitting out messages for dmesg to capture (thus the commands I suggested).

Failing that, I'm sure someone here suggested 'cdrecord -scanbus' from the CDRecord packages. This is limited to SCSI devices once again, but using the 'ide-scsi' kernel emulation, it will allow CD's to be viewed as SCSI devices, but not block IDE hdd's.

/proc/ide/ has some semblance of a device list, but it's a bit messy (having symbolic links to internal structures). If the IDE chipset driver does it (mine here does), it might list devices in a psudo-file here.

Re: finding IDE SCSI disks

Mark Grant — Mon, 13 Oct 2003 03:54:08 GMT

Ok, we seem to have scsi covered (above). Looking through /proc/ide I'm don't think it's too messy. "cat /proc/ide/ide*/hd*/media" seems to do the trick. You'd need to supply your own values for "*" if you want to do more than just count them of course.