Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Programming
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Databases
Mail Systems
openSolaris
Eclipse Documentation
Techotopia.com
Virtuatopia.com

How To Guides
Virtualization
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Windows
Problem Solutions
Privacy Policy

  




 

 

Red Hat Enterprise Linux 8 Essentials Book now available.

Purchase a copy of Red Hat Enterprise Linux 8 (RHEL 8) Essentials in eBook ($24.99) or Print ($36.99) format

Red Hat Enterprise Linux 8 Essentials Print and eBook (ePub/PDF/Kindle) editions contain 31 chapters and over 250 pages

Buy Print Preview Book

21.5. Removing a Path to a Storage Device

If you are removing a path to a device that uses multipathing (without affecting other paths to the device), then the general procedure is as follows:
Procedure 21.2. Removing a Path to a Storage Device
  1. Remove any reference to the device's path-based name, like /dev/sd or /dev/disk/by-path or the major:minor number, in applications, scripts, or utilities on the system. This is important in ensuring that different devices added in the future will not be mistaken for the current device.
  2. Take the path offline using echo offline > /sys/block/sda/device/state.
    This will cause any subsequent I/O sent to the device on this path to be failed immediately. Device-mapper-multipath will continue to use the remaining paths to the device.
  3. Remove the path from the SCSI subsystem. To do so, use the command echo 1 > /sys/block/device-name/device/delete where device-name may be sde, for example (as described in Procedure 21.1, “Ensuring a Clean Device Removal”).
After performing Procedure 21.2, “Removing a Path to a Storage Device”, the path can be safely removed from the running system. It is not necessary to stop I/O while this is done, as device-mapper-multipath will re-route I/O to remaining paths according to the configured path grouping and failover policies.
Other procedures, such as the physical removal of the cable, followed by a rescan of the SCSI bus to cause the operating system state to be updated to reflect the change, are not recommended. This will cause delays due to I/O timeouts, and devices may be removed unexpectedly. If it is necessary to perform a rescan of an interconnect, it must be done while I/O is paused, as described in Section 21.9, “Scanning Storage Interconnects”.

 
 
  Published under the terms of the Creative Commons License Design by Interspire