Multi-Initiator SAS

Multi-Initiator SAS

[Darrick J. Wong]

Hi everybody!

Alexis and I connected both a Adaptec 9410 and a LSI 1064E SAS initiator
to an expander.  Both machines saw the disks attached to the expander,
and both could send I/Os to the disks.  So far, so good.

We then connected a SATA disk to the expander.  libsas BUGd up in
sas_ex_discover_end_dev (sas_expander.c:636):

BUG_ON(sas_port_add(phy->port) != 0);

mptsas didn't seem to do anything with the SATA device at all, though
when we disconnected the SATA disk it recognized that a SATA device went
away.  We'll have a look at the libsas problem in a jiffy.

--D

Re: Multi-Initiator SAS

[Darrick J. Wong]

Douglas Gilbert wrote:

> With the mptsas driver you can use smp_utils to look
> at that expander via /dev/mptctl ('modprobe mptctl' first).
> To get an overview of what the expander sees, try:
>  # smp_discover -mb /dev/mptctl

Unfortunately, I see this:

root@elm3a253:~# smp_discover -mb /dev/mptctl
MPTCOMMAND ioctl failed: No such device
ioctl failed
smp_send_req failed, res=-1

...a strace of the app reveals this:

stat("/dev/mptctl", {st_mode=S_IFCHR|0660, st_rdev=makedev(10, 220),
...}) = 0
open("/dev/mptctl", O_RDWR)             = 3
brk(0)                                  = 0x508000
brk(0x529000)                           = 0x529000
ioctl(3, 0xc0486d14, 0x508010)          = -1 ENODEV (No such device)

--D

RE: Multi-Initiator SAS

[Moore, Eric]

On Tuesday, September 19, 2006 1:15 PM,  Darrick J. Wong wrote:

> Alexis and I connected both a Adaptec 9410 and a LSI 1064E 
> SAS initiator
> to an expander.  Both machines saw the disks attached to the expander,
> and both could send I/Os to the disks.  So far, so good.
> 
> We then connected a SATA disk to the expander.  libsas BUGd up in
> sas_ex_discover_end_dev (sas_expander.c:636):
> 
> BUG_ON(sas_port_add(phy->port) != 0);
> 

Which expander are you using?  I believe James has some sata work
arounds
for the sasx12, which has byte ordering issues.

Eric

RE: Multi-Initiator SAS

[Moore, Eric]

Darrick J. Wong wrote:

> Douglas Gilbert wrote:
> 
> > With the mptsas driver you can use smp_utils to look
> > at that expander via /dev/mptctl ('modprobe mptctl' first).
> > To get an overview of what the expander sees, try:
> >  # smp_discover -mb /dev/mptctl
> 
> Unfortunately, I see this:
> 


You need to pass the sas address of the expander.

./smp_discover --sa=sas_address /dev/mptctl

where sas_address can be found in
/sys/class/sas_device/expander-X:0/sas_address

Re: Multi-Initiator SAS

[Darrick J. Wong]

Moore, Eric wrote:

> Which expander are you using?  I believe James has some sata work
> arounds
> for the sasx12, which has byte ordering issues.

A Vitesse VSC7160.

Also, I think I might have complained about I/O errors accessing the
SATA disk via mptsas--the SATA disk that we were using (Maxtor 6Y080M0)
yields the same errors when attached to the HBA.  I put in a Hitachi
SATA disk and it was fine with both controllers.

--D