fdisk -l shows sata hdd as hda ??

piyush.ml20 · 09-24-2009, 09:34 AM

i m using rhel5
the fdisk -l shows sata hdd as hda whereas usb drive as sda.
thx in adv.

lazlow · 09-24-2009, 10:36 PM

In some motherboards the bios has an option to treat sata drives like pata drives. I suspect yours is set this way.

piyush.ml20 · 09-25-2009, 07:50 AM

my mobo is intel q35.
the bios is set to treat sata as sata.
also why it is showing pendrive as sda.
it shuld show it as hdb i guess.

lazlow · 09-25-2009, 08:48 AM

Usb devices are normally treated as sdX type drives.

piyush.ml20 · 09-25-2009, 08:55 AM

on my frnd computer rhel5 is showing pendrive as hdb.
what hd and sd stands for.
also can we edit this naming scheme.

ongte · 09-25-2009, 10:06 AM

For SATA hard drives to appear as sd* in RHEL5, the BIOS SATA controller must be set to AHCI mode. Instead of the usual ATA mode. This is usually in the BIOS somewhere. You should do it because using SATA drives in ATA mode limits it's performance.

piyush.ml20 · 09-26-2009, 07:22 AM

yes i also find it.below vista and linux kernel 2.6.19 doesnot support sata by default.
thx for ur help.

lazlow · 09-26-2009, 07:35 AM

You really cannot compare a RHEL .19 kernel with a vanilla .19 kernel. RH back patches their kernels to bring them up to current security levels and near current hardware support levels. So, yes the default RHEL 5.X kernels do support sata.

If you are happy with vista, then by all means use it.

piyush.ml20 · 09-26-2009, 07:49 AM

i m not comparing diff kernels.it's on wikipedia that kernel below 2.6.19 doesnot support ahci n raid support by default.

lazlow · 09-26-2009, 09:52 AM

Yes, but what you have to understand is that RH ADDS stuff to their kernels by back patching their kernels. Once any one version is released it will always have the same base kernel. In the RHEL5.X series it will always have a 2.6.19 based kernel, BUT they back patch that kernel to current security levels and near current hardware support levels (as close as they can come and still maintain compatibility). RHEL5.3's 2.6.18-164 is far closer to a vanilla .27 kernel than it is to a vanilla .19 kernel.

piyush.ml20 · 09-26-2009, 10:15 AM

chk this
"AHCI is fully supported out of the box for Microsoft Windows Vista and the Linux operating system from kernel 2.6.19" at

http://en.wikipedia.org/wiki/Advance...ller_Interface

i understand redhat 2.6.19 is different from vanilla 2.6.19.
but the statement i guess means any flavour of linux whose kernel version is 2.6.19 or greater will support ahci mode by default.that doesn't mean diff linux flavours have same kernel.

sorry maybe i m not getting your point or vice-versa.

lazlow · 09-26-2009, 10:50 AM

Because RH ADDS stuff(back patches) to their kernels without changing the revision number (.19 in RHEL5.X) it supports a LOT of things that are not supported in a vanilla .19 kernel. Therefore any statements about the limitations of a vanilla kernel (your wiki link) do not necessarily apply to a RH kernel. As I stated before:

Quote:

RHEL5.3's 2.6.18-164 is far closer to a vanilla .27 kernel than it is to a vanilla .19 kernel.

As I am currently running 5.3 on a sata drive I can assure you it does in fact support sata and has since at least 5.0.

DrLove73 · 09-26-2009, 05:00 PM

Here is what all the fuss is about:

Quote:

Originally Posted by piyush.ml20

yes i also find it.below vista and linux kernel 2.6.19 doesnot support sata by default.
thx for ur help.

piyush.ml20 wrote "below vista and linux kernel 2.6.19" and meant "below vista and (below) linux kernel 2.6.19" not below vista and (for) linux kernel 2.6.19.

So you both are saying the same thing.

piyush.ml20 · 09-27-2009, 07:03 AM

yes dr love u absolutely got my point.
i hope now lazlow will also understand.

lazlow · 09-27-2009, 07:55 AM

What I said about RH back patching kernels still applies. RHEL4.X runs a 2.6.9 based kernel and RHEL4.X's 2.6.9-89 (and earlier) kernel supports sata too.