Skip to main content

Using LVM together with EMC PowerPath


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 = [ "a|/dev/sd.*|","r|/dev/hd.*|","r|/dev/cd.*|" ]
Labels:

Comments

Post a Comment

Popular posts from this blog

Tuning the nscd name cache daemon

I've been playing a bit with the nscd now and want to share some tips related to tuning the nscd.conf file. To see how the DNS cache is doing, use nscd -g. nscd configuration: 0 server debug level 26m 57s server runtime 5 current number of threads 32 maximum number of threads 0 number of times clients had to wait yes paranoia mode enabled 3600 restart internal passwd cache: no cache is enabled [other zero output removed] group cache: no cache is enabled [other zero output removed] hosts cache: yes cache is enabled yes cache is persistent yes cache is shared 211 suggested size <==== 216064 total data pool size 1144 used data pool size 3600 seconds time to live for positive entries <==== 20 seconds time to live for negative entries
2 comments
Read more

Preventing PuTTY timeouts

Just found a great tip to prevent timeouts of PuTTY sessions. I'm fine with timeouts by the host, but in our case the firewall kills sessions after 30 minutes of inactivity... When using PuTTY to ssh to your Linux/Unix servers, be sure to use the feature to send NULL packets to prevent a timeout. I've set it to once every 900 seconds, i.e. 15 minutes... See screenshot on the right.
1 comment
Read more

Setting up SR-IOV in RHEL6 on PowerEdge servers

Dell Community : "RHEL 6 provides SR-IOV functionality on supported hardware which provides near native performance for virtualized guests. Single-Root I/O Virtualization (SR-IOV) specification, introduced by PCI-SIG details how a single PCIe device can be shared between various virtualization guests. Devices capable of SR-IOV functionality support multiple virtual functions on top of the physical function. Virtual Function is enabled in hardware as a light weight PCIe function. Operating System cannot discover this function as it does not respond to the PCI bus scan and requires support in the host’s driver. As in PCIe pass-through, a Virtual function of a SR-IOV capable card can be directly assigned to the guest operating system. A virtual function driver running in the guest manages this device."
3 comments
Read more