Very Computer

Would someone tell if and how I can configure AIX to work with disks
that are attached via two host controllers?

We are considering buying an OEM RAID unit, with dual attach from the
RAID box to the RS6000 (ie: two adapter cards in each).  I believe
that when AIX cfgmgr runs, it will see each disk twice, and configure
them as seperate disks.  We want to achieve a single disk definition
for each disk, that balances IO across the two paths between the host
and the device, and continue to work if one path fails (eg: host a
controller fails).

We run a similar configuration on our production systems with EMC
disks, and have to run EMC PowerPath software to combine the multiple
views of each disk into a single virtual device that we actually put
into a volume group and use.  Is there any way (preferably generic) to
do the same kind of thing with OEM disks, or are we dependant on
vendor supplied drivers/code/utilities.

ASCII diagram of our proposed config:

+----------------+                     +---------------+
|RS6000          |                     |OEM RAID       |
|AIX v4.3.3      |                     |Some RAID5 LUNs|
|                |                     |               |
|FC adapter 1 ---+---------------------+---FC adapter 1|
|                |                     |               |
|FC adapter 2 ---+---------------------+---FC adapter 2|
+----------------+                     +---------------+

thanx, Pum.

"Pum" <paul_holman...@yahoo.co.uk> schrieb im Newsbeitrag
news:7548d753.0206120419.65658860@posting.google.com...
You need SDD Software and supported FC Adapter.
See Section 4. and 5. about SDD Software

Hajo

Found on the IBM Website.
____________________________________________________________________________
________________

RS/6000 Native Fibre Installation Non-HACMP
2105 Enterprise Storage Server As of April 8, 2002

This checklist provides the steps to do initial attach of RS/6000 native
fibre to the ESS.  This checklist assumes a new install of both the RS/6000
and the ESS.

This checklist was authored by Alex Connolly, IBM Enterprise Storage
Specialist.  The checklist is intended as a personal productivity tool and
is provided on an as is basis.  Please be aware that its contents have not
been certified by IBM.  Please send feedback to aconn...@us.ibm.com.

Preparation - Call IBM AIX Software Support, 1-800-CALL-AIX, and order the
following maintenance:

1. Service Refresh Release 09 or later for AIX 4.3.3.  This should fit on a
single CD-ROM.  Optionally, this can be downloaded from the RS/6000 support
website listed below.
2. Obtain the PTF fixes for the list of attached APARs for AIX 4.3.3.  SP
customers should also obtain the fixes listed for PSSP 3.1.1 and RVSD 3.01.
The PTFs should fit on a single CD-ROM.  These APAR's can be optionally
downloaded from the RS/6000 support website listed below.
3. Download the AIX Host Script for the ESS, fileset ibm2105.rte, from the
following website:
<http://ssddom01.storage.ibm.com/techsup/swtechsup.nsf/support/sddhost...
s>
4. If you are planning on multipathing support, please download SDD
(Subsystem Device Driver) Version 1.3.1.3 and corresponding documentation
from the website:
http://ssddom01.storage.ibm.com/techsup/swtechsup.nsf/support/sddupdates
<http://SSDDOM01.storage.ibm.com/techsup/swtechsup.nsf/support/sddupdates>
5. A utility program is available that will document the AIX vpath/hdisk to
ESS lun layout.  This utility can be downloaded from the website:
http://ssddom01.storage.ibm.com/techsup/swtechsup.nsf/support/sddutil
6. Notes:
a. PSSP, RVSD and GPFS APARs apply only to RS/6000-SP systems.
b. RS/6000 APARs, PTFs and microcode are available under the Preventative
Maintenance option at the following IBM website:
<http://techsupport.services.ibm.com/server/support?view=pSeries>
c. The ESS Host Attachment Guide, SG26-7296-05, Chapter 6, provides
additional information and can be downloaded from the following IBM website:
<http://ssddom02.storage.ibm.com/disk/ess/documentation.html>

Implementation - The following steps should be accomplished on each RS/6000
System or RS/6000-SP Node to support attachment to the ESS:

1. If not already installed, install AIX 4.3.3 base, be sure to include
fibre channel support:
a. devices.pci.df1000f7 for FC6227 and FC6228 fibre adapter.
b. devices.pci.df1000f9 for FC6228 fibre adapter.
c. devices.fcp.disk.
d. devices.fcp.disk.array.
e. devices.common.IBM.fc.rte.
Note: The base support for fibre adapter FC6228 is available through AIX
APAR IY20367.
2. For SDD multipathing users, install the following from the AIX 4.3.3
base:
a. perfagent.tools
b. bos.adt
c. bos.adt.prof
d. bos.up or bos.mp depending on whether you have single or multiple
processors in your RS/6000.
3. Install the ibm2105.rte fileset on each RS/6000 Server.  The most current
version of this fileset and it's install script can be downloaded from the
SDD website above.  Optionally, the fileset and install script can be found
on a CD-ROM provided with the ESS subsystem.
4. Download and install current microcode for fibre channel adapter. FC6227
uses firmware level SF322A1 or later, FC6228 uses firmware level SF382A1 or
later.
5. Install AIX Service Refresh Release 09 or later.
6. Install the fixes for the AIX 4.3.3 APARs on the attached list and verify
that the fibre filesets on the attachment are at or above the level
indicated.  If necessary, install individual PTF's to bring the filesets up
to the indicated level.
7. Need to obtain fibre cables locally if distance from RS/6000 to ESS
exceeds 30 meters.
8. Need to establish back up procedures for the RS/6000 disks and the ESS.
9. 2109 Fibre Channel Switch should be at firmware level 2.2.1 or later.
10. ESS should be upgraded to microcode level V1.5.1.16 or later.
11. Ensure that paths to the shared luns from host use ESS I/O bays 1 and 4
or I/O bays 2 and 3 as pairs.
12. Obtain WWPN's for fibre adapters.  These can be obtained by issuing the
AIX command, lscfg -vl fcsx,  for each fibre adapter.  The WWPN is the field
labeled Network Address.
13. Define hosts for each fibre adapter using the WWPN's from above.
14. Set ESS fibre adapters to:          Arbitrated Loop for RS/6000 to ESS
direct attach.      Point to Point for RS/6000 SAN fabric attach to ESS.
15. Confirm RS/6000 adapters have appropriate setting: AL or PT-to-PT.  If
not correct, run the following commands to reset the adapter:
      rmdev -dl fscsix where x is the fcs number.       rmdev -dl fcsx -R
where x is the fcs number.
16. Attach RS/6000 fibre to the ESS, perform cfgmgr -l fcsx for each fibre
adapter and ensure all hdisks are available.
17. For SDD users, download SDD V1.3.1.3 code and documentation for AIX
V4.3.3 and install SDD.  SDD does not currently support SAN Data Gateways or
RVSD.
18. To complete the installation of SDD follow the instructions in the SDD
manual for using SMITTY to Define the Data Path Devices.  Make sure you have
all file systems unmounted.  Optionally, you can reboot the RS/6000 to
complete this step.
19. Run the lsvpcfg command to verify vpaths are available and configured
correctly, i.e., correct number of hdisks per vpath and that both vpaths and
hdisks are available.
20. Volume groups must now be made up of vpaths instead of hdisks.
Reference the SDD manual for details.
21. Verify RS/6000 and ESS operations.
22. Information for Oracle Data Base users using asynchronous I/O to raw
volumes:
a. Apply Oracle defect number 866200 throttling asynchronous I/O which is
included in Oracle base code version 8.1.6 and above.
b. Tune AIX asynchronous I/O handler on AIX (aio0).  Raise default value of
4096 to 16384, 32768 or 65536.  To view the current setting, type
'lsattr -El aio0'.  The value can be changed via 'smitty aio0'.  Also adjust
'miniservers' to 10 and 'maxservers' to 80.

Recommended APARs for AIX 4.3.3 for Fiber Channel and ESS Support
As of April 8, 2002

Component APAR PTF Description
AIX 4.3.3   AIX 4.3.3 Service Refresh Release 09 or later.

AIX 4.3.3 IY15138  Asynchronous I/O on data base raw volumes.
 IY17902  FC I/O hang after Shark warmstart or cable pull error inject.
 IY18070  cfmgr fails to add a device.
 IY23369  heavy fc i/o and large queue depth
  U481918 devices.pci.df1000f7.com.4.3.3.80
  U480886 devices.pci.df1000f7.diag.4.3.3.77
  U480809 devices.pci.df1000f7.rte.4.3.3.76
  U481895 devices.fcp.disk.rte.4.3.3.76
  U474275 devices.fcp.disk.array.diag.4.3.3.50
  U481919 devices.fcp.disk.array.rte.4.3.3.79
  U475697 devices.common.IBM.fc.rte.4.3.3.75

  U478411 devices.pci.df1000f9.diag.4.3.3.75 if using fibre adapter FC6228
  U480808 devices.pci.df1000f9.rte.4.3.3.76 if using fibre adapter FC6228

The maintenance below is for SP customers only.

PSSP 3.1.1 IY03104
 IY07130  SSD Not Supported
 IY09260
 IY04782  For SP FC2054 POWER3 SMP High Node and FC2055 SP Expansion I/O
Unit only.
 IY04804  For SP FC2054 POWER3 SMP High Node and FC2055 SP Expansion I/O
Unit only.
 IY04819  For SP FC2054 POWER3 SMP High Node and FC2055 SP Expansion I/O
Unit only.

RVSD 3.01 IY04249
 IY11783

GPFS 2.1 IY05124

____________________________________________________________________________
________________

SDD supports specific RAID units only. The documentation above is for the IBM
ESS unit. Better to ask the RAID vendor what software to use.

Is it possible to run AIX 5.1?  It provides an EMC Powerpath equivalent function
as part of the OS.

Are you sure ?. AFAIK does  "sdd" not depends on a special external
hardware.
Certainly the FC adapter must be supported.

Hajo

We already have FC6227 FC adapters installed in the systems we propose
to connect the OEM RAID to.

Upgrading to AIX v5 is probably a year or so away, due to resourse
constraints - ie: we're all to busy! :)

I was hoping to find a utility that would do something like what
PoerPath does for our EMC disks.  It sounds like SDD might do it, but
there seems to be some disagreement about whether it'll work with
any/many OEM RAID boxes, or just IBM.  If anyone has a definative
answer, or any other ideas, then I'd appreciate it.  I'll look at the
SDD links when I get some time.

thanx, Pum.

No it doesn't - you may have seen something which looks like it does and may presage
things to come, but one should be careful about reading tea-leaves.

Hi Pum, who is the disk vendor? I think Hitachi use IBM SDD as well as
IBM.

Hi Simon,

I've made enquires of a number of OEM vendors of RAID units.
Impressive price per GB, but all aimed primarily at PC server market,
with a bit of Linux it seems.  We just need cheap storage for
developement systems, but would really like the resilience of dual
path, as it should only cost the price of an extra adapter at each
end, the cable between them, and some software to resolve the dual
disk images back into one - hence the enquiry.

thanx, Pum.

We are now looking at IBM FAStT200 units, which I believe come with
disk management software to handle the multi-pathing issue.  I am
awaiting more details from our IBM var tech people.

Thanx for all your help. Pum.

FAStT Products come with an RDAC driver that provides load balancing.

An earlier document I read said this functionality would be included in AIX
5.2, due out "soon", so you should be able to connect somthing like the IBM
ProFibre Array for $.03/megabyte and make it hum. Can't recall where.

Also, if you chose to run Veritas Foundation Suite, DMP (dynamic multi
pathing) is part of the product.

Mickey

Quote:> We are now looking at IBM FAStT200 units, which I believe come with
> disk management software to handle the multi-pathing issue.  I am
> awaiting more details from our IBM var tech people.

> Thanx for all your help. Pum.