Re: [gentoo-user] Questions about SATA and hot plugging.

Dale <rdalek1967@×××××.com> [10-12-14 18:28]:
> Helmut Jarausch wrote:
> >On 12/14/10 17:42:40, Dale wrote:
> >
> >>Hi,
> >>
> >>I got one more hard drive to move over and it is SATA.  Question one,
> >>can the new mobo's do hot plugging for SATA drives?  I have a plug on
> >>the front of the case and was wondering since it is on the front if
> >>they
> >>
> >If this is an eSATA connection then it works just fine out of the box.
> >It's helpful to write some UDEV rule e.g. in /etc/udev/rules.d/10-
> >local.rules, e.g.
> >SUBSYSTEMS=="scsi", ATTRS{model}=="WDC WD10EADS-65L",
> >SYMLINK="WDExt%n"
> >which generates the /dev/WDExt ... /devWDExt4 devices if there are
> >e.g. 4 partitions on that drive. Thus you can write a fixed entry
> >in your fstab using these devices.
> >
> >
>
> So this is doable then.  Interesting.  ^_^
>
> >>can be hot swapped or if I need to shutdown then hook it up.  If I
> >>can
> >>
> >>hot swap, where does the power come from?  I know the drives I put in
> >>the case have a separate power connection.  How's that work exactly?
> >>Is
> >>that just for external drives that have their own power?
> >>
> >>I have two dries in here already.  One I bought and one that was
> >>donated.  This is what hdparm reports:
> >>
> >>fireball ~ # hdparm -tT /dev/sda
> >>
> >>/dev/sda:
> >>   Timing cached reads:   6788 MB in  2.00 seconds = 3395.32 MB/sec
> >>   Timing buffered disk reads:  328 MB in  3.01 seconds = 109.06 MB/
> >>sec
> >>fireball ~ # hdparm -tT /dev/sdb
> >>
> >>/dev/sdb:
> >>   Timing cached reads:   6736 MB in  2.00 seconds = 3367.58 MB/sec
> >>   Timing buffered disk reads:  324 MB in  3.01 seconds = 107.69 MB/
> >>sec
> >>
> >Exactly the same here, the external SATA drive is even slower
> >/dev/sdd:
> >  Timing cached reads:   7498 MB in  2.00 seconds = 3750.67 MB/sec
> >  Timing buffered disk reads: 262 MB in  3.02 seconds =  86.70 MB/sec
> >
> >
> >>fireball ~ #
> >>
> >>Is that about normal?  The mobo is 3Gbs/sec and the drives are too.
> >>Shouldn't they be faster than that?  I read at one time that SATA is
> >>basically plug up and it works.  Just checking if there is a setting
> >>I
> >>
> >>need to change.
> >>
> >>Related to the above, in the BIOS, it is set to Native IDE.  Should
> >>that
> >>be set to AHCI instead?  Is that why it is slower than expected?  Is
> >>that good to go with Linux as well?  I have this set in the kernel
> >>and
> >>
> >>built in as usual:
> >>
> >>AHCI SATA support
> >>
> >I'have configured my BIOS like that. It's working just fine.
> >
> >
> >>Let me know if I am somewhat right on anything.  Oh, I decided to
> >>name
> >>
> >>the new rig fireball instead of lightening.  ;-)  You may notice that
> >>in
> >>the paste up above.
> >>
> >>
> >Helmut.
> >
> >
>
> Well, according to the mobo book, AHCI "enables advanced SATA
> features".  Me, I read that and I think that it may mean faster.  It
> also says it is set to native by default for OS's that can handle only
> native mode controllers.  I just don't want to try it without making
> sure it is not going to lead to some sort of file system problems or
> something.  I did some Googling but most of the stuff I find is from
> years ago and things have changed a lot since then.
>
> Thanks for the info.
>
> Dale
>
> :-)  :-)
>


In the linux kernel configuration you can set AHCI for Sata...
But whether this technically option is addtionally a wise one?
I dont know...