EMC ax4-5i + RHEL5 + iSCSI

fishjohn · 07-29-2010, 04:40 PM

Hi,

I have 4 virtual disk on AX4-5i.
RHEL for some reason shows 16 partitions in /proc/partitions .

I got lot-lot of IO errors in dmesg. Some of those 16 partitions "work", others just give (on using fdisk for example): Unable to read /dev/sdb

on EMC I have 4 ports, so it might be somehow releated to this.

Quote:

[root@db ~]# /etc/init.d/iscsi restart
Logging out of session [sid: 1, target: iqn.1992-04.com.emc:cx.sl7e2101800014.a0, portal: 192.168.10.101,3260]
Logging out of session [sid: 2, target: iqn.1992-04.com.emc:cx.sl7e2101800014.b0, portal: 192.168.10.103,3260]
Logging out of session [sid: 3, target: iqn.1992-04.com.emc:cx.sl7e2101800014.a1, portal: 192.168.10.102,3260]
Logging out of session [sid: 4, target: iqn.1992-04.com.emc:cx.sl7e2101800014.b1, portal: 192.168.10.104,3260]
Logout of [sid: 1, target: iqn.1992-04.com.emc:cx.sl7e2101800014.a0, portal: 192.168.10.101,3260]: successful
Logout of [sid: 2, target: iqn.1992-04.com.emc:cx.sl7e2101800014.b0, portal: 192.168.10.103,3260]: successful
Logout of [sid: 3, target: iqn.1992-04.com.emc:cx.sl7e2101800014.a1, portal: 192.168.10.102,3260]: successful
Logout of [sid: 4, target: iqn.1992-04.com.emc:cx.sl7e2101800014.b1, portal: 192.168.10.104,3260]: successful
Stopping iSCSI daemon:
iscsid dead but pid file exists [ OK ]
Starting iSCSI daemon: [ OK ]
[ OK ]
Setting up iSCSI targets: Logging in to [iface: default, target: iqn.1992-04.com.emc:cx.sl7e2101800014.a0, portal: 192.168.10.101,3260]
Logging in to [iface: default, target: iqn.1992-04.com.emc:cx.sl7e2101800014.b0, portal: 192.168.10.103,3260]
Logging in to [iface: default, target: iqn.1992-04.com.emc:cx.sl7e2101800014.a1, portal: 192.168.10.102,3260]
Logging in to [iface: default, target: iqn.1992-04.com.emc:cx.sl7e2101800014.b1, portal: 192.168.10.104,3260]
Login to [iface: default, target: iqn.1992-04.com.emc:cx.sl7e2101800014.a0, portal: 192.168.10.101,3260]: successful
Login to [iface: default, target: iqn.1992-04.com.emc:cx.sl7e2101800014.b0, portal: 192.168.10.103,3260]: successful
Login to [iface: default, target: iqn.1992-04.com.emc:cx.sl7e2101800014.a1, portal: 192.168.10.102,3260]: successful
Login to [iface: default, target: iqn.1992-04.com.emc:cx.sl7e2101800014.b1, portal: 192.168.10.104,3260]: successful
[ OK ]

[root@db ~]#

I've googled and read docs but got no idea what to do. Really appreciate if anyone can share her/his experiences with EMC/RHEL/iSCSI - I just don't understand where those 16 (and half of them not working/giving lotof errors) come from?

For example Citrix Xen on similar network conf can see/use same EMC thoughr iSCSI nicely.
SO there should'nt be network/auth issues (not using CHAP btw).

I got feeling that problem is on RHEL iscsi conf side.

Thanks in advance ..

grim76 · 07-30-2010, 08:30 PM

Are you using multipath by chance? I know on our FC san we see devices for the other paths that we have to the storage. Keep in mind that depending on how you are setup the other devices may not be available until you have an SP failover. I don't recall if the AX-4 series worked as an active-active san or if it was and active-passive (failover).

bstafford51 · 08-02-2010, 10:19 AM

Read the documentation carefully and you'll find that this is a characteristic of the AIX4-5si. I ran into the same problem in both Linux and Windows. It sucks but there isn't much you can do about it.

fishjohn · 08-03-2010, 03:44 AM

But wonder that it works find on Citrix Xen.
When on citrix xen console (bash) I type dmesg, no erros are seen.

And Citrix Xen should be basically RHEL ?