Enabling SPC-2 on RH 4 U7

Question

We have assigned new dmx storage to RH 4 cluster system and they are unable to see these new disks. These systems are able to access the previously assigned dmx storage without any problems. EMC is suggesting us to enable SPC-2 on wwn level to resolve this. Has anybody tried this? Does this affect FA port or any other systems on these FA ports? We have different systems (windows, vm, hp, linux) on these FA ports and want to make sure that by enabling SPC-2 it would not affect the FA port or the other systems. Would I also be able to disable SPC-2 after enabling it without any disruption to any systems on the FA port and FAs? symcli 6.5.3

dynamox · Answer

you absolutely can enable and disable FA flags on per host bases without affecting anybody else. We are doing that for our Exchange 2007 boxes that required SPC-2 flags, even though SPC-2 was not enabled on FA level.

Davidy8s · Answer

I think Dynamox got it...

Still have this remaining though about disabling, correct?

"Would I also be able to disable SPC-2 after enabling it without any disruption to any systems on the FA port and FAs?

symcli 6.5.3"

Dave Yates
EMC TSE3
Benevolent Host S/W & Mainframe Forum Moderator

VP1 · Answer

Yes, I am still skeptical as we never had this issue with 6.4 before so want to make sure that this is really required and if it messes up something we can revert back the change.

dynamox · Answer

take a look at this discussion as well:https://forums.emc.com/forums/thread.jspa?messageID=515313񽳱

dynamox · Answer

yes, you can disable on the fly without affecting any other systems on the FA. This is a masking command where you specify host's WWN ...that is the ONLY host you are impacting.

VP1 · Answer

Thanks dynamox and mistery for you replies - do you know if this is (disabled SPC2) definitely causing the RH systems to not see this additional DMX storage?

dynamox · Answer

not sure, i would not think so unless RH clustering is doing some kind of masking and does not allow the host to see it until clustering is configured. I would think regardless if clustering is enabled or not you should be able to see the disk in syminq / inq output. I ran your config through E-Lab navigator and they list the following flags are required:

(C) Common Serial Number4
(D) Disable Queue Reset on Unit Attention4
(SC3) SCSI-3 compliance
(SPC-2) SPC-2 compliance

Optional:

(OS2007) Host SCSI Compliance

xe2sdc · Answer

Don't forget you can check flags using symmask command.You don't need an Excel sheet

Sawhney_Akshat · Answer

We can set the SPC-2 Bits at two diffrent levels.
1. On FA 2. On HBA of the Host.

if u set the SPC-2 on FA, then it may have impact on the otherhost Looking on the devices from the same FA, So in your case as there are windows,vm,hp and Linux hosts looking throufh the same FA, there are more changes of Impact on these hosts. So the Best way is to Set the SPC-2 Bit at HBA level only, So that only the concerned host see this change, But one thing need to be taken care in this case is, if there is a HBA failure, then when the HBA is replaced, then you need to set the BIT again.

So the Best way is to keep the note of all the Bits set at the HBA level in an Excel Sheet...

Hope this answer your worry.

Regards
Akshat Sawhney

Sawhney_Akshat · Answer

I am just saying this from customer prospective,

Because what i have generally seen is that they have very dynamic working environment, Pleople come and go so if they have some standard document to fallow then its easy for them to keep track of changes..

VP1 · Answer

Thank you all for your responses, we have enabled the SPC2 flag on host/wwn level. So far everything looks fine.

ranjancom2000 · Answer

Anyone help me below command is correct to enable bit setting from host level if I have two HBA

HBA 01

symmask -sid 1065 set hba_flags on SPC2 -enable -wwn hba01-WWN -dir 1D -p 0

HBA 02
symmask -sid 1065 set hba_flags on SPC2 -enable -wwn hba02-WWN -dir 16D -p 0

Some more questions

After enable the bit setting are we need the restart the host to scan the new device
How can we check the bits setting in symcli for every host
What setting I need to use “set heterogeneous” on or off. If I use multiple OS sharing the same FA Port

dynamox · Answer

your commands look good

1) yes, you need to restart your host

2) you will need to run this command and look for "Port Flag Overrides section:

symmaskdb -sid 123 list db -wwn HBA -v

3) you don't need to use "set Heterogeneous" if you are using hba_flags. I typically set the most command flags on the FA itself and then set specific OS flags using symmask hba_flags command.

ranjancom2000 · Answer

What is best setting in FA level if we use FA for windows,Solaris,Vmware,Linux

Can i use this below FA setting

          Volume_Set_Addressing(V)     : Disabled
              Non_Participating(NP)        : Disabled
              Init_Point_to_Point(PP)      : Enabled
              Unique_WWN(UWN)          : Enabled
              VCM_State(VCM)               : Enabled
              OpenVMS(OVMS)                : Disabled
              AS400(AS4)                        : Disabled
              Auto_Negotiate(EAN)          : Disabled

What is best setting in FA level if we use FA for windows,Solaris,Vmware,Linux,HP-unix,Aix

         Volume_Set_Addressing(V)     : Enabled
              Non_Participating(NP)        : Disabled
              Init_Point_to_Point(PP)      : Enabled
              Unique_WWN(UWN)           : Enabled
              VCM_State(VCM)               : Enabled
              OpenVMS(OVMS)                : Disabled
              AS400(AS4)                        : Disabled
              Auto_Negotiate(EAN)          : Disabled

dynamox · Answer

I would recommend you visit E-Lab navigator, add all the systems you have in your environment and look for FA flags that are common among all OS’s in your shop. Set those flags on the FAs and whichever flag is needed by specific OS ..set those via symmask hba_flags.

Host Systems

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