External eSATA drive doesn't fdisk properly ? F8 eSATA hotplug ?

[linux guy]

I've got a new laptop with an eSATA port and a new (unformatted) eSATA
external hard drive.

Is eSATA hot plug compatible with a stock F8 kernel ?

$ uname -a
Linux localhost.localdomain 2.6.26.3-14.fc8 #1 SMP Wed Sep 3 03:40:05 EDT
2008 i686 i686 i386 GNU/Linux

$ /sbin/lsmod | grep sat
sata_sil24             16069  0
libata                131937  3 ata_piix,sata_sil24,ahci


The reason I ask is because I expected to be able to plug it in and do an
fdisk /dev/sdc and set up a new partition.  (My laptop has 2 internal hard
drives, sda and sdb, so sdc should be the external eSATA drive, right ?)

When fdisk failed, I resorted to hwbrowser.  It stalled/crashed.

I repeated the experiment after a reboot with the drive powered up, ie not
hotplugged anymore, with the same results.

What am I missing ?

Thanks

[Joseph L. Casale]

> I've got a new laptop with an eSATA port and a new (unformatted)
> eSATA external hard drive.
>
> Is eSATA hot plug compatible with a stock F8 kernel ? 
Good question, and I don't know but I wonder if helping it find it might work.
Figure out what host# that interface is on, then issue this:

#echo "- - -" > /sys/class/scsi_host/host{n}/scan

Run an #fdisk -l after, I wonder if it appears then?

HTH,
jlc

[linux guy]

On Mon, Sep 29, 2008 at 8:27 PM, Joseph L. Casale <JCasale(a)activenetwerx.com
>  wrote: 
>  >I've got a new laptop with an eSATA port and a new
> (unformatted) eSATA
>  external hard drive.
>  >
>  >Is eSATA hot plug compatible with a stock F8 kernel ?
>
>  Good question, and I don't know but I wonder if helping it find it might
>  work.
>  Figure out what host# that interface is on, then issue this:
>
>  #echo "- - -" > /sys/class/scsi_host/host{n}/scan
>
>  Run an #fdisk -l after, I wonder if it appears then?
>  
I think the problem is deeper than if the kernel supports ESATA hotplug.
Even if I have the drive plugged in when I boot, hwbrowser hangs until I
shut the drive off.   Something is wrong with situation.  I'll do some
groundwork and report back.

[linux guy]

My laptop has the Intel 82801HBM/HEM (ICH8M/ICH8M-E) SATA AHCI Controller.
(hwbrowser)

According to http://linux-ata.org/driver-status.html, Linux supports full
hotplug for this chipset.

=============================================

AHCI (newer Intel ICH, ULi, others)
 Driver name: ahci
 Summary: Full NCQ support, full SATA control including hotplug and PM.
 Note1: AHCI specification is completely open.
 Note2: ATI, Intel, JMicron, NVIDIA, SiS, ULi and VIA are currently known to
have deployed AHCI in their chipsets.
 Hopefully others will follow. AHCI is a nice, open design.

============================================

My laptop has 2 internal SATA drives and they work perfectly, including with
hwbrowser.

So why does hwbrowser stall with the external drive ?

[Joseph L. Casale]

> So why does hwbrowser stall with the external drive ? 
Don't know, maybe its broken? Did you try to initiate a (re)scan of
the applicable bus manually and then enumerate it with fdisk?

[Ed Greshko]

Joseph L. Casale wrote:
> > So why does hwbrowser stall with the external drive ?
> >     
>
>  Don't know, maybe its broken? Did you try to initiate a (re)scan of
>  the applicable bus manually and then enumerate it with fdisk?
>
>     
I suppose the first thing I would do is to boot the system without the
external disk connected.  Then, I would "tail -f /var/messages" while I
plugged in the drive and see what the system is saying....  But that is
just what I would do.

-- 
A man with 3 wings and a dictionary is cousin to the turkey.

[Ed Greshko]

Ed Greshko wrote:
>  Joseph L. Casale wrote:
>    
> >> So why does hwbrowser stall with the external drive ?
> >>     
> >>       
> > Don't know, maybe its broken? Did you try to initiate a (re)scan of
> > the applicable bus manually and then enumerate it with fdisk?
> >
> >   
> >     
>  I suppose the first thing I would do is to boot the system without the
>  external disk connected.  Then, I would "tail -f /var/messages" while I
>  plugged in the drive and see what the system is saying....  But that is
>  just what I would do.
>
>     
Of course that is /var/log/messages....  :-)

-- 
There's no future in time travel.

[linux guy]

Interesting tidbit... the external drive has 2 interfaces.  USB and eSATA.
I just mounted the drive and formatted it via USB without any problems.  Now
hwbrowser doesn't crash when the drive is connected via eSATA.  But the
drive doesn't appear in eSATA either.

[linux guy]

On Mon, 2008-09-29 at 18:27 -0600, Joseph L. Casale wrote:
>  >I've got a new laptop with an eSATA port and a new
> (unformatted) eSATA external hard drive.
>  >
>  >Is eSATA hot plug compatible with a stock F8 kernel ?
>  
>  Good question, and I don't know but I wonder if helping it find it might work.
>  Figure out what host# that interface is on, then issue this: 
How do I find out what host a device is running on ?  

Thanks

[Joseph L. Casale]

> How do I find out what host a device is running on ?
>
> Thanks 
Well, using the 2.4 kernel method of /proc,
on a small server exporting some iSCSI targets here, I get this:

[root@host ~]# #cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
  Vendor: ATA      Model: ST3160812AS      Rev: 3.AA
  Type:   Direct-Access                    ANSI SCSI revision: 05
Host: scsi1 Channel: 00 Id: 00 Lun: 00
  Vendor: ATA      Model: ST3160812AS      Rev: 3.AA
  Type:   Direct-Access                    ANSI SCSI revision: 05
Host: scsi2 Channel: 02 Id: 00 Lun: 00
  Vendor: LSI      Model: MegaRAID 8888ELP Rev: 1.12
  Type:   Direct-Access                    ANSI SCSI revision: 05
Host: scsi2 Channel: 02 Id: 01 Lun: 00
  Vendor: LSI      Model: MegaRAID 8888ELP Rev: 1.12
  Type:   Direct-Access                    ANSI SCSI revision: 05


But that's being deprecated by the /sys in the 2.6 kernels, and aside from
looking manually which can be tedious, I just install lsscsi,

[root@host ~]# lsscsi
[0:0:0:0]    disk    ATA      ST3160812AS      3.AA  /dev/sda
[1:0:0:0]    disk    ATA      ST3160812AS      3.AA  /dev/sdb
[2:2:0:0]    disk    LSI      MegaRAID 8888ELP 1.12  /dev/sdc
[2:2:1:0]    disk    LSI      MegaRAID 8888ELP 1.12  /dev/sdd

If your distro doesn't have lsscsi or you don't want to install it just use
the /proc method...

So to rescan everything on the 8888ELP, I would issue:
[root@host ~]# echo "- - -" > /sys/class/scsi_host/host2/scan

Which is exactly what I use to enumerate any new arrays I configure via the
MegaRAID cli when I can't reboot if for example I can not unmount a target.

HTH,
jlc