This post uses the qlogic dynamic target and lun discovery utilities. Adding and removing san disks from suse device manager. The general process is to add or resize the lun on the san, rescan the servers scsi layer to detect the changes, rebuild the mpio maps, and then add or modify the filesystem. Stop all file access to the lun to be removed and umount the filesystem if applicable. Scsi adapter number host channel number bus id number target lun lun lun is the common scsi abbreviation of logical unit number. Resizing storage luns in linux on the fly standalonesysadmin. If the device is a member of an lvm volume group, then it may be necessary to move data off the device using the pvmove command, then use the vgreduce command to remove the physical volume, and optionally pvremove to remove the lvm metadata from the disk. Clean up the rules created earlier to mask the lun. Learn how to create a lun, how to share a lun, and find out about lun provisioning and lun masking. Adding,resizing and removing luns without restarting sles. I am planning to remove luns from a standalone server next week and am curious to see if the result is still the same.
The sanlun utility is a user application that retrieves and displays information about luns on a netapp controller. The post mentions few ways to exactly identifymatch the lun presented from san with underlying os disk. When you are working in a storage environment, it is often desirable to add, remove or resize storage devices. Remove any reference to the devices pathbased name, like devsd, devdisk bypath or the major. Remove the device from any md and lvm volume using it.
Document feedback vmware welcomes your suggestions for improving our documentation. In this tutorial i will help you to remove lun safely from a running system, this method should work on all redhat based systems 5 6 or 7, with command. On the modify iscsi target lun setup page, add luns to the target group, edit the lun assignments, or remove target luns from the group. Setting up a unix host to use fibre channel fc storage.
Sep 22, 2019 in my earlier article i shared a step by step guide to configure iscsi target and initiator to setup a multipath san storage using your centos rhel 7 linux machine. May 02, 2009 suppose ive got a san storage array, and ive created a lun essentially a disk segment that ive presented to my server. How to remove a san disk or storage device lun from linux server. Remove a san lun device from linux the multipath devices can be removed with multipath f, when the multipath device is unused, i. Now compare hostx info with target with previous command procscsiscsi to obtain details which disk is mapped to which lun id. Suppose ive got a san storage array, and ive created a lun essentially a disk segment that ive presented to my server. Note that removing a san lun or disk is a semitedious process that must be followed. If the lun is still not seen, a reboot may be required. Removing lun from server powerpath for linux powermt. Once storage is allocated we need to scan and verify allocated storage san disk. Please make sure that an iscsi target has been created and ready for use in thesan nas targets. Check hba card and its drivers info on linuxrhel6 linux sysfs filesystem. Add, resize and remove lun without restarting sles or. Linux multipath boot from san redhat 5 installing on multipath san lun from scratch.
Login to the storage server vnx, vmax and remove the host from the storage group or the lun in the storage group. Unclaim any paths left over after the lun has been removed. We have a qlogic qle2560 hba running on a centos 6 server. Their are 2 luns attached to a p200 g3 san and i can not find anything documented for this os on how to remove them. Sans are primarily wont to build storage devices, like disk arrays, tape libraries, and optical jukeboxes, accessible to servers in order that the devices appear as if regionally connected devices to the package. In this tutorial i will help you to remove lun safely from a running system, this method should work on all redhat based systems 5 6 or 7, with command multipath ll you can all details about your luns and.
The numbers marked at the end represent host, channel, target and lun. Log in to your red hat account red hat customer portal. Guide to scandetect new luns on linux linux rescan scsi. A storage area network san could be a dedicated network that has access to consolidated, block level information storage. The general process is to add or resize the lun on the san, rescan. Suns native path management software is sun storedge traffic. Create the lun on the san, and assign it to the server. And per redhat they remove vg which does not make sense if i destroy vgfilesystem i can remove the corresponding lun and recreate it. Mar 05, 2009 note that removing a san lun or disk is a semitedious process that must be followed. After all desired changes have been made to the group, click next. I make my physical volume on the device in this case, dev.
Create a lun, map it to the server, create the appropriate zones. The process varries depending on how you are using your disk. In this article, let us discuss how to use powermt command with practical examples. Removing a storage device red hat enterprise linux 5 red. If lvm was used on the devices to be removed, make sure that no logical volumes, volume groups or physical volumes are still present in use on the relevant devices. Now remove the lun from the storage group clariion or unmap it from the fa ports dmx. Is the disk part of a logical volume and under continue reading remove a lun from redhat. Safely removing an iscsi storage volume from a linux host. Removing a storage device red hat enterprise linux 5.
The older method would allow you to remove a lun and present a different lun back, and have esx 3. To fully purge the systems information about a particular lun, you should also remove the devsd devices underlying the multipath device. I do not have any software from qlogic installed on the device. Explore logical unit number lun storage and its role in san management.
This article i will show commands to scan and detect. Removing manually configured fcp luns and their scsi device. On a linux server, i am removing a clariion san presented lun. Modern linux can be installed on multipath devices natively, so prepare all paths be available and online. For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration. This article tells how to hot add, delete,rescan scsi devices. Emc powerpath for linux installation and administration guide. Whenever i copy files in that lun correspondingly thin provisioned lun s used space increases but when i remove files to free up space the lun s size isnt decreased. Jun 12, 2011 when you are running redhat enterprise linux 5, 6, and 7 series system with dmmultipath and the software iscsi initiator, you can discover new luns by rescanning the iscsi service on the host. A logical unit number lun is a number used for identifying a logical unit relating to computer storage. On the linux server, run powermt display to verify that the device has been removed. Add, resize and remove lun without restarting sles. The second method of configuring luns for a linux system with only lun 0 configured involves setting the parameter for the scsi midlayer driver that controls how many luns are scanned during a scsi bus scan. How to delete iscsi target from initiator centos rhel 7.
A devices wwn worldwide name is an identifier much like an mac address in ip networking and is essentially equivalent to the eui in the iscsi side of things. Hot add, remove, rescan of scsi devices on linux finding informations about scsi devices the first problem when working with scsi devices might be to map informations you got from procscsiscsi to the device names the kernel uses like devsda and so on. Recently, i had to remove a san lun on a physical enterprise linux system. In the same article i had given brief steps to remove or delete iscsi target. Hot add, remove, rescan of scsi devices on linux fibrevillage. Run the multipath ll command, note the uuid the big hex number, lun and sdx device of the disk, eg in the example below it is lun 2. How to add lun to a san file system linux has a four level hierarchical addressing scheme for scsi devices.
This guide was created as an overview of the linux operating system, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter. Oct 19, 2010 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. The first step was to alter the multipath service configuration file. Removing a storage device red hat enterprise linux 7 red. This entry was posted in linux and tagged centos, disk, from, host, iscsi, linux, multipath, remove, removing, san, server, storage, volume by ben. Note that it is critical to follow the procedures in exact order because deviating from. How to remove san attached luns from rhel 5 servers using. For information on how to enable the hba bios, see your vendor specific documentation. How to remove a san disk or storage device lun from linux server step 1. Removing manually configured fcp luns and their scsi. Remove a san lun device from linux hewlett packard.
Powermt management utility helps you manage io paths from the server to the emc storage device. Instructions to perform boot from iscsi for dell storage arrays. Just confirm this is in fact the one you want to remove crosscheck the lun and. Nov 21, 2011 my best guess for this behaviour is that in vsphere 4.
Oct 22, 2010 to remove a lun and all associated powerpath and linux devices from the host environment follow these steps. The first step was to alter the multipath service configuration file etcnf and make the daemon reload its configuration. Removing lun safely when using multipathing has anyone been able to find a clean way of removing a lun from a redhat linux server that uses multipath. An iscsi san usually consists of the following components. The storage admin removed the lun from the storage group to unpresent it. Check and list luns attached to hba in rhel6 fibrevillage. Note that it is critical to follow the procedures in exact order because deviating from the procedures can cause the host to panic. Unmount the filesystem it is critical to stop all io on the device that is being removed. To configure failover in linux, see your iscsi target user guide to create multiple connections to the operating system iscsi lun in the linux operating system once installation and boot is complete. However, dynamic storage changes are dependent upon the hardware and software. If the disk is not seen, repeat this step using different command line parameters to scan for all devices i. Following info related to hp hardware with qla adapters. Rescanning the service will display all the newly created luns that have been mapped to the host. Mask the lun from the esx host by creating new rules in the psa pluggable storage architecture physically unpresent the lun from the esx host using the appropriate array tools.
Intended audience the information presented in this manual is written for experienced windows or linux system administrators who are familiar with virtual machine technology datacenter operations. Native multipath failover is packaged with the hpux operating system software. To remove a lun and all associated powerpath and linux devices from the host environment follow these steps. Failure to do so will result in your server being left in a funky state. Remove san storage device from linux server hewlett packard. Lazysystemadmin linux quick howto san remove luns from linux safely.
Just confirm this is in fact the one you want to remove crosscheck the lun and size of the volume on the. Removing lun from server powerpath for linux powermt issue on the final time doing this the result was consistent and one dead path remains. Remove san storage device from linux server no such thing that im aware of. In san environment, there is a easier way to manage san scsi devices, see sysfs fibre channel tools. When you are running redhat enterprise linux 5, 6, and 7 series system with dmmultipath and the software iscsi initiator, you can discover new luns by rescanning the iscsi service on the host. Check and list luns attached to hba in rhel6 this article will show you the mapping from physical hba card to luns, i use san as example below, in general, its also applys to any other devices whichever use sysfs, for example direct sas connect. Jun 27, 2012 to verify that the lun was added before a metadata server is up, you can enter the cat procpartitions command.
Jan 29, 2015 a storage area network san could be a dedicated network that has access to consolidated, block level information storage. Removing lun from server powerpath for linux powermt issue. Removing manually configured fcp luns and their scsi device in your san configuration on suse linux enterprise server 12 sp4 for ibm z mainframe. Remove luns from linux safely october 22, 2010 linux quick howto san. Their are 2 luns attached to a p200 g3 san and i can not find.
I have opened case to ibm to address the issue but they stated that there is nothing wrong with the storage and that i should follow os instructions to release removed blocks. My best guess for this behaviour is that in vsphere 4. Lun remove, stuck in devdsk and devrdsk so, we removed a lun from the san and the system is refusing to remove the references to it in the dev folder. How to configure san storage server on centos 6 techbrown. After a metadata server is up, you can enter the lslun command to view the list of luns available to san file system. Now you can pvcreate devdmxx, vgextend volgroup devdmxx, etc remove a disk. This website to share our expertise and knowledge on linux, unix, windows, hardware, security, cloud and open source. Jun 10, 2018 logical unit number lun a lun is a construct, usually on a storage array, with which you present a slice of a disk arrayvolume to a host, where it appears as a physically attached local disk via some connection, usually san iscsifc. Removing lun from server powerpath for linux powermt issue hi, i am sure a reboot will be the fix for this, but i am trying to understand what the issue is or if there is some other way to correct it.
A list of devices which have been discovered and are recognized by the scsi subsystem are listed in procscsiscsi. Above indicates that hsv110 is a storage disk and it also give the lun numbers with scsi information like here it shows scsi2 is a san disk if you wana know abt the san partition do this dmesg grep i attached attached scsi disk sda at scsi0, channel 0, id 0, lun 0 attached scsi disk sdb at scsi2, channel 0, id 0, lun 2. Jun 18, 2010 lazysystemadmin is a useful howto website that covers system administration, operating systems, cloud, devops, virtualization, scripts and video tutorials. In this guide let us see how to safely remove a san disk lun from red hat enterprise linux version 5, 6 or 7 and its variants like centos. A logical unit is a device addressed by protocols and related to fiber channel, small computer system interface scsi, internet scsi iscsi and other comparable interfaces. I can add luns dynamically without having to reboot. May 04, 2017 recently, i had to remove a san lun on a physical enterprise linux system. If you are using two nics, one as primary and the other as the secondary.
Lun identification for a linux host system in linux 2. How to remove a san disk or storage device lun from. These steps were put together using steps from qlogic kb articles. Because im intelligent and plan ahead, im using lvm to manage it. Instructions to perform boot from iscsi for dell storage. Logical unit number lun a lun is a construct, usually on a storage array, with which you present a slice of a disk arrayvolume to a host, where it appears as a physically attached local disk via some connection, usually san iscsifc. 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 powermt management utility helps you manage io paths from the server to the emc storage device. We have an netapp san utility to fetch details about mapped luns, host bus adapter wwwn details, path of the associated lun to linux disk. Suse linux enterprise server 12 service pack 1 sles 12 sp1. Enable san booting in the server bios for the ports to which the san boot lun is mapped. Adding iscsi storage to a linux computer this article describes mounting iscsi luns from san iscsi targets to linux hosts.