On Fri, Jan 21, 2011 at 3:58 PM, Ross Walker rswwalker@gmail.com wrote:
On Jan 21, 2011, at 6:41 PM, Edward Morbius dredmorbius@gmail.com wrote:
We've been wrestling with this for ... rather longer than I'd care to admit.
Host / initiator systems are a number of real and virtualized CentOS 5.5 boxes. Storage arrays / targets are Dell MD3220i storage arrays.
...
You need the RDAC kernel module installed, this handles asymmetric multipathing to these devices.
You can get this from Dell's site.
Once this is installed you need to setup dm-multipath, look for multipathd.conf in /etc, get the product id and vendor id from dmesg after making an initial connection via open-iscsi and use that in the mutipath config. Your going to need to use path utility 'rdac' in the config instead of tur.
Google is your friend here.
We've got *an* rdac module installed. Any way of telling whether or not this is Dell's? RPM says these are from kernel-2.6.18-194.17.1.el5.src.rpm.
$ lsmod | grep rdac scsi_dh_rdac 43977 0 scsi_dh 42177 2 scsi_dh_rdac,dm_multipath scsi_mod 196953 14 scsi_dh_rdac,be2iscsi,ib_iser,iscsi_tcp,bnx2i,cxgb3i,libiscsi2,scsi_transport_iscsi2,scsi_dh,sr_mod,sg,libata,megaraid_sas,sd_mod
$ rpm -qif $(locate rdac.ko) Name : kernel Relocations: (not relocatable) Version : 2.6.18 Vendor: CentOS Release : 194.17.1.el5 Build Date: Wed 29 Sep 2010 11:57:11 AM PDT Install Date: Thu 14 Oct 2010 02:17:14 PM PDT Build Host: builder10.centos.org Group : System Environment/Kernel Source RPM: kernel-2.6.18-194.17.1.el5.src.rpm Size : 96488290 License: GPLv2 Signature : DSA/SHA1, Thu 30 Sep 2010 08:35:49 AM PDT, Key ID a8a447dce8562897 URL : http://www.kernel.org/ Summary : The Linux kernel (the core of the Linux operating system) Description : The kernel package contains the Linux kernel (vmlinuz), the core of any Linux operating system. The kernel handles the basic functions of the operating system: memory allocation, process allocation, device input and output, etc. Name : kernel Relocations: (not relocatable) Version : 2.6.18 Vendor: CentOS Release : 194.17.1.el5 Build Date: Wed 29 Sep 2010 11:57:11 AM PDT Install Date: Thu 14 Oct 2010 02:17:14 PM PDT Build Host: builder10.centos.org Group : System Environment/Kernel Source RPM: kernel-2.6.18-194.17.1.el5.src.rpm Size : 96488290 License: GPLv2 Signature : DSA/SHA1, Thu 30 Sep 2010 08:35:49 AM PDT, Key ID a8a447dce8562897 URL : http://www.kernel.org/ Summary : The Linux kernel (the core of the Linux operating system) Description : The kernel package contains the Linux kernel (vmlinuz), the core of any Linux operating system. The kernel handles the basic functions of the operating system: memory allocation, process allocation, device input and output, etc.
There's also a rebuild of 'sg', with a source tree in /usr/src/sg-3.5.34dell
Diffing sources:
$ diff sg.c sg.c_rhel5 22c22 < #define SG_VERSION_STR "3.5.34dell" ---
#define SG_VERSION_STR "3.5.34"
1879c1879 < sg->length = (ret_sz > num) ? num : ret_sz; ---
sg->length = ret_sz;
I'll also note that Dell isn't playing nice with its package installs -- some stuff is under /opt/dell, some is installed via RPM, some appears to be tossed arbitrarily onto the system:
$ rpm -qif /lib/modules/2.6.18-194.17.1.el5/extra/sg.ko file /lib/modules/2.6.18-194.17.1.el5/extra/sg.ko is not owned by any package
Bad Dell. No donut.
-Ross
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