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Comments (14)

kareem33 commented Nov 14 2018 Comment Permalink

Great post Chris.
I'm trying to make it useful for configuring IBM GDR.
GDR itself works very fine with recreating LPAR, creating VIOS mappings, reversing replication direction.
But there is important problem - after DR operation I must reconfigure my machine. Most important is IP configuration.
I can see that using ghostdev may be good - I suppose it's better to have working hdisk0-hdisk9 instead of defined hdisk0-hdisk9 plus available hdisk10-hdisk19, but I'll think of it more.
Final case is post-DR config. You use scripts in /etc/inittab. You provided one here - could you please provide second one also?
You refer to files like /usr/local/dr/dr_en0.txt - what are these files? Just "interface IP mask" or something like this?
Thanks in advance.


Nazar_KA commented Jan 14 2017 Conversation Permalink

Thanks Chris for the wonderful article .
But we have issue to recover our Power HA 7.1.3 environment in DR .

We restored the mksysb and other Luns we replicated ..but the caa was not coming up .
Could you please help with the better procedure to recover PowerHA in DR with replicated caa and data vg disks .

cggibbo commented Jan 16 2017 Conversation Permalink

Hi, there is a way to recover CAA. Send me an email (cgibson@au1.ibm.com) and I will share the details with you. Cheers, Chris.

PreciousGift commented Feb 17 2016 Comment Permalink

Procedure for using bitwise copy for creating new servers:
It used to be that we will do the following to create, say server2 from
server1:
nim mksysb server1
nim define machine object server2
nim standalone server installation to server2 using mksyb_server1
Add the default route to server2

We are now using the following process for the cloning:
on server1:
chdev -l sys0 -a ghostdev=2
create a cloned copy of the rootvg disks using some SAN function.
assign the new clone disks to a new LPAR
boots up the new LPAR
chdev -l inet0 -a hostname=server2 -a route=default_route_settings
chdev -l en0 -a netaddr=server2_ip_address -a netmask=server2_netmask
/usr/sbin/rsct/install/bin/recfgct
/usr/sbin/rsct/bin/rmcctrl -z
/usr/sbin/rsct/bin/rmcctrl -A
/usr/sbin/rsct/bin/rmcctrl -p

With the above process, I confirmed that for server2, its pvid is
changed and DLAR functions work on it.

I am still a little bit concerned that the above process may not be
equivalent to a mksysb backup and restore. Can you confirm it? Did I
miss anything?

ratsou commented Jan 9 2016 Conversation Permalink

Thank you for your article that helped me a lot on understanding the replication of rootvg.

To improve our RTO, I'm looking for a solution that would also create system requirements for the HMC LPAR and VIO LPAR

A solution such as RSS (SIMPLIFIED REMOTE RESTART) may be appropriate, but it seems to me that the FSP production should be reached, limiting the value of RSS in case of crash..

An idea ?
















cggibbo commented Jan 19 2016 Conversation Permalink

Yes, you are correct. The FSP must be available for RR to work. You could write a script that sync's/creates the LPAR profiles at the DR site.

AbhilashMenacheril commented Sep 13 2015 Comment Permalink

Did anyone try this in a CAA environment ? I mean in a Power HA 7.1 sysmirror. I believe the CAA cluster will not work in both cases :
1. If ghotdev is set, the ODM is wiped which in turn will remove the CAA cluster too.
2. If ghostdev is not set, the CAA replicated disk will have a different logical device name and UDID, which will disturb the CAA cluster.
However, the nodeid has to be regenerated which can be done without much hassles.
Do we have a way out to get the Power HA replicated on the DR as it is ?

mikekelley1981 commented Feb 18 2015 Comment Permalink

Im impressed how they handle their support. Had several issues to fix, and they were glad to help me with my server ( http://www.spectra.com/hitachi/used-system/107/index.htm ) issue.

cggibbo commented Apr 8 2013 Comment Permalink

We generate new WWPNs at the DR site. Thanks for sharing James. Very interesting setup and I 'm glad its all working OK for you.

Jame5.H commented Apr 8 2013 Comment Permalink

So are the same WWPN's preserved for the Primary/DR partition? My biggest issue was creating the NPIV devices on the DR hardware from a replicated rootvg which generated new device WWPN's that had to be zoned seperately to all of the storage devices. I'm in the process of deploying our first AIX servers for our organisation for TSM v6.3 and essentially we're doing the same thing on AIX 7.1.... Redundant VIOS at each site with redundant SAN per VIOS, all data LUNS including rootvg are SAN attached using SVC vdisks, with syncronoush metro-mirroring to DR. Our test so far has included an AIX 7.1 client lpar running TSM v6.3.3.0 with replicated san attached VSCSI for rootvg, NPIV VFC attached data luns, NPIV VFC attached 3592 libraries (22 drives in total), plus a NPIV VFC attached Protectier (16 virtual LTO) TS7650G. Using SDDPCM and IBM atape control path / data path failover, I can shutdown the TSM server, break the replication and power on the DR partition and not lose any data in the DB2 db, or on a file storage pool that had not yet been migrated to tape and it all comes online at the DR site in 5 minutes without the need to restore a TSM DB or an AIX Operating system from backups. I also, tested changes to the client at the DR site and replicating back and it all works ok. Although I didin't know about ghostdev, but the rootvg is presented via the two VIOS as VSCSI (not NPIV VFC) and had no issues booting, I did notice that the hdisk count increased, but all the VG's sorted themselves out fine. Stale dev's came back online as the original device id's once I failed back to the prod site.

brian_s commented Sep 26 2012 Comment Permalink

Great post Chris. I hadn't heard about the ghostdev attribute before. It will definitly come in handy.

aldridged commented Sep 20 2012 Comment Permalink

Excellent article chris. Some good pointers and a new attribute to use