But due to this activity the mapping between pseudo name and logical device id changed due to unknown reason. The uuid for all devices is the same sda1, sdb1, sdc1, sdd1, emcpowera1 because they point at the same file system, just via different paths. It provides automated path management and tools that enable you to satisfy aggressive servicelevel agreements without investing in additional infrastructure. This command checks for available emc san logical devices and add those to powerpath configuration list. July 9, 20 may 4, 2018 init linux leave a comment on emc powerpath on solaris. Nov 08, 2015 powerpath is emc licensed software for managing san attached storage on your systems.
Linux device mapper example fc only when you use device mapper, there are multiple ways for you to set pseudo device names or aliases. Use powerpath with powerpath multipathing for linux, unix, and windows to standardize path management across physical and virtual environments. Emc powerpath for linux installation and administration guide. Optimize data paths in your virtual environment now. Since this server is using powerpath, i have four devices, all with the same uuid sda, sdb, sdc and sdd. Sep 21, 2018 in order to use powerpath pseudo devices in solaris running veritas volume manager, one need to run the powervxvm utility. Using emc powerpath devices with vxvm in previous versions of vxvm, it was necessary to perform powervxvm init and powervxvm online to use emc powerpath devices with vxfas. In this post we will cover how to install, license and scan for newly attached storage.
Since powerpath and the thirdparty software cannot comanage devices, do not initiate comanagement by executing this command if this software is present support for this array type is disabled in powerpath hdlm hitachi lightning, hitachi tagmastore. I am planning to remove luns from a standalone server next week and am curious to see if the result is still the same. I have a backup software that requires that all the devices presented in linux to have different uuid. Download the powerpath software from emc powerlink website. There are two linux multipath io available emc powerpath and dm multipath though both have each pros and cons.
I am going to talk about emc powerpath upgrade on aix. Provide viable and robust multipath io capability for linux operating systems on dell poweredge servers and dellemc storage systems. Nov 18, 2008 this software allows one to map the os devices to a pseudo block device without having to worry about the device paths. I am in the process of migrating from powerpath to linux devicemapper multipath. Ive seen these change in some heavy duty testing back in 2006 2. This lun masking only needs to be performed on hosts where powerpath is installed, so i am attempting to test each host to determine this. Find answers to emc lun to device mapping from the expert community at experts exchange.
The issue i am having is that no matter what i do, power path see the luns as active and alive. Previously when i have done this on other system the next step is to create an asm disk on the new partition and add this disk to the oracle disk group. I am aware of various issues with asm and powerpath, but i dont think this is the issue here. This happened as emc powerpath software assigned the pseudo device ids based on the new device config as recognized by os and without noticing the difference, they issued powermt config. Download your nocharge, 45day powerpath ve trial software today. The uuid for all devices is the same sda1, sdb1, sdc1, sdd1, emcpowera1 because they.
To have powerpath scan all devices and mark any dead devices as alive, if it finds that a device is in fact. In the following example, emc powerpath 5 emcpower. Emc powerpath is one of the best multipathing software that is used on the servers and not only it is stable but it is very easy to use, today i would like to show how to install it and to change the pseudo device name, sometimes when you are working on server where the luns are shared you want the device name to be same so that you can find them. Emc powerpath software emc powerpath is a family of software products that ensures consistent application availability and performance across io paths on physical and virtual platforms. Either powerpath of the native fcnvme multipath software should be configured and present the devices using pseudo device names for example, devemcpowera when using powerpath, or devnvme0n1 when using native fcnvme multipath. Emc powerpath is a software designed for load balancing, path management, and device management. In our setup we did not use the san for boot though we use internal storage on each host for the osboot and use the san storage for applicationsdbs.
Running powermt display devall will show you which devsd devices are associated with each of your pseudo devices. The powerpath pseudo device naming convention and therefore the device permission is the same, regardless of whether you are using fc or fcnvme. I have installed powerpath and was expecting to see hdiskpower emc devices for powerpath, but powerpath doesnt create hdiskpower devices. We did migrate from powerpath to hitachis cci horcminqraid software and linux native multipath though. Before you can use the emc powerpath software, you should register it using the emc powerpath license key received when you purchased the software from emc. Emc lun to device mapping solutions experts exchange. Disable powerpath boot and auto varyon option for the datavgs. I have been pulling my hair out trying to determine how to do this with powercli. Some daemon is still keeping the pseudo device andor its native paths open. We have brought the server up by commenting the san filesystem in etcfstab and stopping multipathing. May 16, 2008 i will present some notes about the use of multipath solutions on red hat systems.
Powermt management utility helps you manage io paths from the server to the emc storage device. For example, write throttling off, hba mode active, clariion policy claropt, etc. How to determine if emc powerpath is installed on an esx. The pseudodevice provides a backdoor for gaining root access for a particular user. I then created a new partition in on the pseudo device, to use the new space. The luns i am looking to remove are on the dmx not the clarion i have no issues removing clarion luns. Powermax fcnvme deployment with linux part ii setup. Powermt config command, sets some of the options to its default values. If youve lost the powerpath registration key that youve used during the how to install and configure emc powerpath on linux, you can retrieve it using the following command. Refer to veritas volume manager administators guide for more information on foreign device support. Afterwards, restart the powerpath software andd crosscheck the device names via powermt command.
Can anybody help to create a pseudodevice and write a device driver for it. This software allows one to map the os devices to a pseudo block device without having to worry about the device paths. Also installed qlogicsuperinstallerrel2015u1201506306, and hba is loaded on kernel. Powermax fcnvme deployment with linux part i overview. Emc powerpath multipathing software device mappermultipath is not affected by this issue. Getting the powerpath to work is a huge problem, and i am trying to determine what the best course of action. Part of the unix paradigm is that everything is a file and programs can use file operations read andor write to interact with the system, so to load up randomness for crypto functions, you do a file read on devrandom or devurandom which connects you to the rng. On linux, while the backend io paths are still alive i. Mapping between pseudo name and logical device id in. If underlying singlepath devices are not filtered out, lvm discovers, thus reports the duplicate device paths that all reference the same lvm device. However i have now recieved the final production server and need to set this all up again. Powerpath migration enabler user guide knowledge ascent. Removing lun from server powerpath for linux powermt.
How to migrate from powerpath to multipath boot lun is on. List available powerpath pseudo device nameslist used powerpath pseudo device names or rename powerpath pseudo device. It also integrates multiplepath io capabilities, automatic load balancing, and path failover functions for complete. Customer had already expanded the user capacity for these two luns on the vnx. Verified that the target pseudo devices has already been removed from the management of lvm or oracle asm, etcs rebooting the host does not work, either. Dell emc powerpath 7 is the first powerpath release that provides fcnvme multipath support. Took me a minute to get this line, but its so clever. How to migrate from powerpath to multipath boot lun is on san. Hello emc community, i have a doubt that maybe some of you have already figured out. After installation, administrators can start powerpath by issuing the command service powerpath start. With native devices, you must manually configure the application after the. Hi, i migrated data from our dmx to our clarion and would like to reclaim the dmx luns.
Server considerations deployment best practices for. Hey guys, we use powerpath on rhel servers, with at least 2 paths to each disk, as you know the powerpath creates a pseudo devices called emcpowerx. Migration powerpath to linux multipath hewlett packard. Its man page man powermt provides specific information about the utility. The number one in health check software for linux and unix. Before you start emc powerpath installation and configuration, make sure hba cards are installed on the server and fiber channel switches are zoned properly. Red hat enterprise linux 5 rhel5 red hat enterprise linux 6 rhel6 emc clariion san vendor. When preparing your storage to use asm, first determine the storage option for your system and then prepare the disk storage for the specific operating system environment as described in this chapter. But when i run multipath to check status, it agains go to kernel panic. Emc powerpath how to change psuedo names using powermt. Along those notes, keep in mind that they were based on tests done when pressure was very high to put new systems in production, so lack of time resulted in less complete tests than expected.
Now unmount all the filesystems and stop the volume manager if any to release the pseudo devices. How to install and configure emc powerpath on linux. Emc powerpath powermt command examples ramesh peram. For some reason i thought that it directly zeroes out the bits of the free space, but instead it creates a file filled with zeroes, which fills the free space. Powerpath migration enabler supports migrations using powerpath devices pseudo devices or native operating system devices. If you want to remove lun from linux this is the procedure. Since powerpath and the third party software cannot co manage. Both native and pseudo device names will be visible to vxvm and in the vxdisk list output. Emc powerpath powermt command windows administrators blog. The software features includes powermt, a powerful management utility for its devices. In fact, only one path is available to the pseudo device like emcpowere. Emc powerpath not creating hdiskpower devices i have an aix 5. I am in the process of migrating from powerpath to linux device mapper multipath.
Customer was trying to expand two in native linux lvm filesystem san luns, that are mapped in native linux lvm,and it failed. In order to use powerpath pseudo devices in solaris running veritas volume manager, one need to run the powervxvm utility. To avoid confusion, we can remove the native devices from view using vxdiskadm vxprint shows the type of device used. Powerpath just keeps track of opens sent down from the userland to determine if any process or processes is using a device and if any opens are active, then powerpath will not allow to remove the device from its control. When considering linux native multipathing software for fcnvme, there are two options. I have another almost identical node and it has both paths available, although a couple of them are not using their default sp here also. Dec 05, 2012 emc powerpath is one of the best multipathing software that is used on the servers and not only it is stable but it is very easy to use, today i would like to show how to install it and to change the pseudo device name, sometimes when you are working on server where the luns are shared you want the device name to be same so that you can find them easily and sometime make your troubleshooting. Renaming emcpower pseudodevices on two linux cluster nodes jump to solution no correlation at all just wanted to make sure that policy is set to claropt if you do have license installed, once you do get the license, install it and set policy to claropt to get the benefits of loadbalancingfailover. If your server has two hba cards connected to emc san storage device, you can implement loadbalancing, and failover on the hba cards using the emc powerpath software. How to expand a linux filesystem even though there is no. If youve purchased emc support, you should have access to powerlink.
I do not want to pull the rug out from under the os so i have not tried unmasking them from the fas. Removed the device file as suggested with rmsf a but this caused the io path in pp to become unknown so i could not do the remove with a force. Installing powerpath and changing the emc pseudo device name. Jul 09, 20 if the output of powermt display devall indicates that some storage system logical devices are not configured as powerpath devices. It doesnt really matter how is named the device if the multipath software cant recognize it unless for human intervention in case of a software failure in order to reconfigure it properly.
Found duplicate pv warnings when using lvm with multipath. Powerpath 7 provides full multipathing functionality for fcnvme, including path failover, loadbalancing, and high performance. One way to recover from such a scenario would have been to copy the device config from the good node to this node. Residing on the server, powerpath multipathing enhances san performance and application availability. Available for aix and red hat enterprise linux systems.
In our environment, we are using emc powerpath on most but not all of our hosts. List available powerpath pseudo device namesused pseudo device names rename powerpath pseudo device. If you dont have nf file, you must be having a latest version. Emc powerpath on solaris linux administration blog. Since powerpath and the thirdparty software cannot comanage devices, do not initiate comanagement by executing this command if this software is present support for this array type is disabled in powerpath hdlm hitachi lightning, hitachi tagmastore devices, do not initiate comanagement by executing this command if this software is present support for this. Since powerpath and the third party software cannot co. Remove lun from linux and powerpath sysadmin tips and. Removing lun from server powerpath for linux powermt issue on the final time doing this the result was consistent and one dead path remains.
How to install and config powerpath on rhel life of a geek. Migrations are nondisruptive with pseudo devices, which means an application never has to be brought down through the entire migration process. If you are not installing powerpath software then reboot the server. This is how powerpath determines if a device is busy, according to pp dev team. Jan 10, 2020 either powerpath of the native fcnvme multipath software should be configured and present the devices using pseudo device names for example, devemcpowera when using powerpath, or devnvme0n1 when using native fcnvme multipath. Jun 27, 2011 emc powerpath multipathing automatically tunes your storage area network san and selects alternate paths for your data if necessary. Raid5 it is currently unknown if other sans are affected. This chapter describes how to prepare your storage subsystem before you configure automatic storage management asm.