ioconfig limit - assignment order

[Viktor Balogh]

Hi all,

I would have a question regarding ioconfig. We have a server and the customer asked me how many LUNs can be assigned to this machine unti we reach the limit of ext_bus (which is in fact at 255).

As you see the last instance is the number 255 in our current configuration:

# ioscan -fnkC ext_bus | awk '{print $2}' | sort -un | tail
246
247
248
249
250
251
252
253
254
255
#

But some ext_bus instances are missing:

# ioscan -fnkC ext_bus | grep ext_bus | wc -l
84
#

My question would be: do we need to clean up the ioconfig in order to assign new LUNs to the machine? I mean are these ext_bus instances assigned serially (that's making us to reorganize the io tree), or will the instance number be assigned to the next free slot? (...so we won't have any problem by assigning a LUN to here.)

Could you help me to figure out how many more LUNs can be assigned? They need to be visible on two FC paths, so I think one LUN will occupy two ext_bus instances.

# echo "(256-84)/2" | bc
86
#

This way 86 LUNs can be assigned to here. Am I correct?

[Viktor Balogh]

ok, I forgot the OS version: 11.11

[Viktor Balogh]

>They need to be visible on two FC paths, so I think one LUN will occupy two ext_bus instances.

Ok, I read some stuff about it... My assumptions wasn't correct, for a single ext_bus instance 16 targets can be mapped. And for a single target there can be 8 separate LUNs zoned. That's 256x16x8 for each 11.11 box.

[Duncan Edmonstone · Accepted solution]

>> My question would be: do we need to clean up the ioconfig in order to assign new LUNs to the machine?

Very probably - the easiest way being to mv the /etc/ioconfig and /stand/ioconfig files to new names and then reboot to LVM maintenance mode - expect to have to recreate all your LVs using vgimport or vgscan (including vg00) and potentially to have to rework your LAN configurations to (as lan3 might not come back as lan3). Plenty of preparation in terms of ignite backups and outputs of ioscan, netstat -in, vgexport -p -s etc. etc. is the secret of making this work right. You will find several different approaches to doing this if you search the forums for ioinit and ioconfig


HTH

Duncan

[Viktor Balogh]

Thank you Duncan. I will leave this topic open and report back later.

[Viktor Balogh]

Thread closed. ioconfig was cleared.

[Viktor Balogh]

FYI: At a similar case, the new ext_bus instances were generated automatically on the free slots.

Before the LUN assignment:

# ioscan -fnkC ext_bus | sort -nk2 | tail
ext_bus 246 0/6/1/1.2.3.0.0 fcd_vbus CLAIMED INTERFACE FCP Array Interface
ext_bus 247 0/6/1/1.2.3.255.0 fcd_vbus CLAIMED INTERFACE FCP Device Interface
ext_bus 248 0/6/1/0.2.2.0.0 fcd_vbus CLAIMED INTERFACE FCP Array Interface
ext_bus 249 0/6/1/0.2.2.255.0 fcd_vbus CLAIMED INTERFACE FCP Device Interface
ext_bus 250 0/6/1/0.2.3.0.0 fcd_vbus CLAIMED INTERFACE FCP Array Interface
ext_bus 251 0/6/1/0.2.3.255.0 fcd_vbus CLAIMED INTERFACE FCP Device Interface
ext_bus 252 0/2/1/0/4/0.1.8.0.0 fcd_vbus CLAIMED INTERFACE FCP Array Interface
ext_bus 253 0/2/1/0/4/0.1.8.255.0 fcd_vbus CLAIMED INTERFACE FCP Device Interface
ext_bus 254 0/2/1/0/4/0.2.8.0.0 fcd_vbus CLAIMED INTERFACE FCP Array Interface
ext_bus 255 0/2/1/0/4/0.2.8.255.0 fcd_vbus CLAIMED INTERFACE FCP Device Interface
#

# ioscan -fnkC ext_bus | wc -l
88
#

after the new LUNs were zoned:

# ioscan -fnkC ext_bus | wc -l
94
#

[Viktor Balogh]

forgot to mention the details/system version:

# uname -a
HP-UX hpconn3 B.11.11 U 9000/800 728233732 unlimited-user license
# model
9000/800/rp4440
#