Oracle: Unbreak my Linux Heart

If you have configured bonding of two or more physical interfaces in a logical bonded interface capable of fail-overs, and you want to know the status of the bond , check /proc! /proc/net/bonding/bond0 shows the status of the bond: $ cat /proc/net/bonding/bond0 Ethernet Channel Bonding Driver: v2.6.3-rh (June 8, 2005) Bonding Mode: fault-tolerance (active-backup) Primary Slave: None Currently Active Slave: eth0 MII Status: up MII Polling Interval (ms): 100 Up Delay (ms): 0 Down Delay (ms): 0 Slave Interface: eth0 MII Status: up Link Failure Count: 1 Permanent HW addr: 00:1a:a0:34:73:dc Slave Interface: eth4 MII Status: up Link Failure Count: 1 Permanent HW addr: 00:15:17:38:b9:2a

Found a little note on Red Hat today, that mentioned to use network bonding mode numbers instead of names. Add settings to /etc/modprobe.conf but use mode={0,1,2,3,4,5,6} to enable load-balancing, active-passive, fail-over or others. Update: also check out documentation on network bonding from the Linux Foundation. Update2: Official Linux kernel documentation on network bonding .

" Oracle Validated Configurations are pre-tested, validated architectures with software, hardware, storage, and networking components with included documented best practices for deployment. Oracle and its strategic partners offer and recommend these configurations to enable end-users to deploy fully tested solutions to achieve standardization with high performance, scalability, and reliability while lowering infrastructure costs."

If you, like me, love LVM for your Linux installations and LVM's ability to add disk space to partitions before they fill up without reboot or unmounting... then you'll be glad to know you can also use LVM if you have EMC PowerPath for your multi-path issues. In a bug fix from 2005, rhn.redhat.com | Red Hat Support , Red Hat lists that you can use Powerpath pseudo-devices with LVM. That way, LVM is unaware of a path failure and will get the fail-over path from PowerPath. Update: What you should do, though, is tell LVM to ignore local devices and only focus on emcpower devices. I distinguish between VMs and bare metal (BM) servers that also have local SAS disks. Here is what I've put in the lvm.conf file: # add EMCpower devices and sdb, reject all other SCSI disks and any CDs #BM#filter = [ "a|/dev/emcpower.*|","a|/dev/sdb|","r|/dev/sd.*|","r|/dev/cd.*|" ] # add any SCSI devices, reject all IDE disks and CDs #VM#filter...

Calivia has a nice little "howto" about doing failover tests of your FibreChannel HBA cards on Linux, to test multipathing software.

Last week I tried to install Oracle Enterprise Linux, aka Unbreakable Linux, on our new PowerEdge 2950 servers. Installation went without a hitch! So that was good news. A look in dmesg showed the two Qlogic QLE2460 HBAs and the on-board Broadcom dual 1 Gb NICs were recognized perfectly. However, SAN people reported no activity or visibilty on the SAN fabric whatsoever. I started to read up on Linux multipath IO (MPIO) and found some documentation there. I will have to go back to the data center and try these thing onsite, as remote access is not working yet. The good news is that MPIO is built-in in Linux kernels since early 2.6 (something like 2.6.5) so by now, these things should be standard. LVM2 includes all the necessary device-mapper packages and utils, so everything should be in place. I simply may need to activate the device mapper with dmsetup or multipathd . We'll see...