How to rescan the SCSI bus to add or remove a SCSI device without rebooting the computer
Issue
- What is recommended procedure for removing a disk from the system?
- I need to remove a disk on a running system, what are the required steps to do so to prevent needing a reboot
- Is it possible to add or remove a SCSI device without rebooting a running system?
- Can you scan a SCSI bus for new or missing SCSI devices without rebooting?
- How can I make newly connected SCSI storage devices available without rebooting?
- What is the Linux equivalent to the Solaris command
devfsadmto add or remove storage devices? - I am trying to add a LUN to a live system but it is not recognized
- I am trying to add a tape drive to a live system but it is not recognized
- I am trying to add a disk drive to a live system but it is not recognized
- How can I force a rescan of my SAN to find newly associated LUNs?
- What to do if a newly allocated LUN on my SAN is not available?
- Unable to probe for a newly allocated LUN
- Some nodes can't see my new storage device, how can I make it available?
- After SAN maintenance activity, not all devices returned - devices in multipath missing or remain in failed state.
- After SAN failover testing completed, not all devices returned to running state as expected - devices in multipath missing or remain in failed state.
- What is the best way to remove a SCSI disk from the system
- What is recommended procedure for removing a disk from the system
Environment
- Red Hat Enterprise Linux 5.0 or above
- SCSI devices over a Fibre Channel or iSCSI transport
Technical support for online storage reconfiguration is provided on Red Hat Enterprise Linux 5 and above. Limited tools for hot adding and removing storage are present in previous releases of Red Hat Enterprise Linux, however, they cannot be guaranteed to work correctly in all configurations. Red Hat Enterprise Linux 5 includes many enhancements to udev, the low level device drivers, SCSI midlayer, and device-mapper multipath, which enables comprehensive support for online storage reconfiguration.
This article, and:
- the Red Hat Enterprise Linux 9 Managing storage devices document,
- the Red Hat Enterprise Linux 8 Managing storage devices document,
- the Red Hat Enterprise Linux 7 Storage Administration Guide,
- the Red Hat Enterprise Linux 6 Storage Administration Guide, and
- the Red Hat Enterprise Linux 5 Online Storage Reconfiguration Guide
...currently cover the FC and iSCSI transports. Future versions of this documentation will cover other SCSI transports, such as SAS and FCoE.
Hewlett-Packard Smart Array controllers that use the cciss driver provide a different interface for manipulating its devices. This is because the cciss driver is a block driver, not a scsi driver and its disks are not SCSI devices. Users of this hardware can see How do I rescan an HP Smart Array for new devices without rebooting? for additional information.
The procedures below also apply to hypervisors (i.e. "dom0" in Red Hat Enterprise Linux 5 virtualization), but the procedures are different for dynamically altering the storage of running virtual guests. For more information about adding storage to virtual guests, see the Virtualization Guide for additional information.
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