topic Re: scsi priority in Operating System - HP-UX

scsi priority

RogerVI — Sun, 27 Nov 2011 00:10:55 GMT

Hi,

I need to extract one internal disk of one server (this is a rp5430 running HP-UX 11i V1 with lvm mirror) because I need to configure the mirror of lvols of another server more critical.
In the server rp5430, I have the following output from stm:

0                    Bus Adapter (803)         Information Successful
0/0                  PCI Bus Adapter (782)     Information Successful
0/0/0/0              Core PCI 100BT Interface Information Successful
0/0/1/0              PCI SCSI Interface (10000 Information Successful
0/0/2/0              PCI SCSI Interface (10000 Information Successful
0/0/2/0.6.0          SCSI Disk (HP18.2GST31840 Information Successful
0/0/2/1              PCI SCSI Interface (10000 Information Successful
0/0/2/1.6.0          SCSI Disk (HP18.2GST31840 Information Successful
0/0/4/1              RS-232 Interface (103c104 Information Successful
...

Then, the two disks are 0/0/2/0.6.0 and 0/0/2/1.6.0.
What do you recommend extract, according to the scsi priority ?
Thanks in advance

Re: scsi priority

Matti_Kurkela — Sun, 27 Nov 2011 19:25:16 GMT

Since the disks are on separate SCSI interfaces, and both buses don't seem to have any other devices connected to them, the SCSI priority will not be an issue.

Disk 0/0/2/0.6.0 is attached to SCSI interface 0/0/2/0 and disk 0/0/2/1.6.0 to SCSI interface 0/0/2/1, respectively.

Both interfaces are physically located on the Core I/O card. According to rp5430 documentation, all core I/O SCSI interfaces and the core LAN share a single 250 MB/s PCI bus (hardware path 0/0).

By the way, are you sure this is a rp5430? According to the hardware paths, the SCSI IDs are 6 on both disks. With rp5430's internal hot-plug disk slots, the values are hardwired to each slot, and should be 0 and 2 on each bus, respectively. I think the paths look more like a rp24xx system.

To confirm the system model, please run the "model" command.

To get the most up-to-date information on disks, you might want to run "ioscan -fnCdisk": if the result does not agree with the output of stm, you might want to tell stm to rescan the hardware.

Re: scsi priority

Torsten. — Mon, 28 Nov 2011 05:52:30 GMT

This is IMHO a rp7400 (aka N4000) - but these disks are on seperate SCSI busses, so there is no difference in priority.

Re: scsi priority

RogerVI — Mon, 28 Nov 2011 15:19:26 GMT

Thanks Matti and Torsten
You are right. I made a mistake. The source server is a rp7400. (i confused because the destination server is a rp5430)
One more question, not directly related to my fisrt question.
The "scsi reset" affect only to scsi interface, or to all pci bus ?

Thanks for your help

Re: scsi priority

Torsten. — Mon, 28 Nov 2011 18:35:11 GMT

Such resets occur "per SCSI bus" - in your case it affects only a single disk.

Re: scsi priority

RogerVI — Wed, 30 Nov 2011 19:53:13 GMT

Thanks