Table of Contents
Advertisement
Quick Links
Red Hat Enterprise Linux
Online Storage Reconfiguration Guide (BETA)
Red Hat Enterprise Linux Documentation
Don Domingo
Copyright © 2008 Red Hat, Inc.
Copyright © 2007 by Red Hat, Inc. This material may be distributed only subject
to the terms and conditions set forth in the Open Publication License, V1.0 or
later (the latest version is presently available at
http://www.opencontent.org/openpub/).
Distribution of substantively modified versions of this document is prohibited
without the explicit permission of the copyright holder.
Distribution of the work or derivative of the work in any standard (paper) book
form for commercial purposes is prohibited unless prior permission is obtained
from the copyright holder.
Red Hat and the Red Hat "Shadow Man" logo are registered trademarks of Red
Hat, Inc. in the United States and other countries.
All other trademarks referenced herein are the property of their respective
owners.
The GPG fingerprint of the security@redhat.com key is:
CA 20 86 86 2B D6 9D FC 65 F6 EC C4 21 91 80 CD DB 42 A6 0E
1801 Varsity Drive
Raleigh, NC 27606-2072
USA
Phone: +1 919 754 3700
Phone: 888 733 4281
Fax: +1 919 754 3701
1
Advertisement
Table of Contents
Related Manuals for Red Hat ENTERPRISE LINUX - ONLINE STORAGE RECONFIGURATION GUIDE BETA
Summary of Contents for Red Hat ENTERPRISE LINUX - ONLINE STORAGE RECONFIGURATION GUIDE BETA
-
Page 1: Red Hat Enterprise Linux
All other trademarks referenced herein are the property of their respective owners. The GPG fingerprint of the security@redhat.com key is: CA 20 86 86 2B D6 9D FC 65 F6 EC C4 21 91 80 CD DB 42 A6 0E... -
Page 2: Table Of Contents
Red Hat Enterprise Linux PO Box 13588 Research Triangle Park, NC 27709 Abstract This guide outlines the different procedures involved in reconfiguring iSCSI, Fibre Channel and SAS storage devices. Beta Document. This document is currently in Beta. Red Hat welcomes any suggestions and corrections;... -
Page 3: Document Conventions
Document Conventions 5, along with first-hand experience in managing storage devices in Linux. Before consulting this book, verify if your host bus adapter vendor or hardware vendor have their own documentation. It is recommended that you consult such documents before reading this manual. -
Page 4: We Need Feedback
If you find a typographical error in this manual, or if you have thought of a way to make this manual better, we would love to hear from you! Please submit a report in Bugzilla: http://bugzilla.redhat.com/bugzilla/ against the product Red_Hat_Enterprise_Linux. -
Page 5: Fibre Channel
Fibre Channel API 2. Fibre Channel This section discusses the fibre channel API, native Red Hat Enterprise Linux 5 fibre channel drivers, and the fibre channel capabilities of these drivers. 2.1. Fibre Channel API Below is a list of directories that contain files used to provide the userspace API. /sys/class/ In each item, host numbers are designated by , bus numbers are... -
Page 6: Native Fibre Channel Drivers And Capabilities
Red Hat Enterprise Linux 2.2. Native Fibre Channel Drivers and Capabilities Red Hat Enterprise Linux 5 ships with the following native fibre channel drivers: • lpfc • qla2xxx • zfcp • mptfc Table 1, “Fibre-Channel API Capabilities” describes the different fibre-channel API capabilities of each native Red Hat Enterprise Linux 5 driver. -
Page 7: Persistent Naming
Persistent Naming iscsiadm -m session -P 0 iscsiadm -m session These commands print the list of running sessions with the format: driver [sid] ip:port,target_portal_group_tag targetname For example: iscsiadm -m session tcp [2] 10.15.84.19:3260,2 iqn.1992-08.com.netapp:sn.33615311 tcp [3] 10.15.85.19:3260,3 iqn.1992-08.com.netapp:sn.33615311 For more information about the iSCSI API, refer to /usr/share/doc/iscsi-initiator-utils-version/README 4. -
Page 8: Scanning For New Devices
Red Hat Enterprise Linux Note In addition to this, you can also use rules to implement persistent naming. udev For more information about this, refer to man udev 5. Scanning for New Devices If you load a driver before adding the corresponding storage device, you will likely need to manually add the new storage to the operating system. -
Page 9: Modifying Link Loss Behavior
Fibre Channel 7. Modifying Link Loss Behavior This section describes how to modify the link loss behavior of devices that use either fibre channel or iSCSI protocols. 7.1. Fibre Channel If a driver implements the Transport callback, access attempts to a device dev_loss_tmo through a link will be blocked when a transport problem is detected. -
Page 10: Iscsi Settings With Dm-Multipath
Red Hat Enterprise Linux Fibre Channel: remove_on_dev_loss If you prefer that devices are removed at the SCSI layer when links are marked bad (i.e. expired after seconds), you can use the module parameter dev_loss_tmo scsi_transport_fc . When a device is removed at the SCSI layer while remove_on_dev_loss remove_on_dev_loss is in effect, the device will be added back once all transport problems are corrected. - Page 11 iSCSI Settings With dm-multipath Intervals between NOP-Out requests are 10 seconds by default. To adjust this, open and edit the following line: /etc/iscsi/iscsid.conf node.conn[0].timeo.noop_out_interval = [interval value] Once set, the iSCSI layer will send a NOP-Out request to each target every [interval value] seconds.
-
Page 12: Iscsi Root
Red Hat Enterprise Linux queue I/O based on the settings in instead of /etc/multipath.conf /etc/iscsi/iscsid.conf 7.3. iSCSI Root When accessing the root partition directly through a iSCSI disk, the iSCSI timers should be set so that iSCSI layer has several chances to try to reestablish a path/session. In addition, commands should not be quickly requeued to the SCSI layer. -
Page 13: Troubleshooting
Troubleshooting The process is different, however, if a device uses the fibre channel protocol and the rport blocked. In such cases, the drivers wait for several seconds for the to become online rport again before activating the error handler. This prevents devices from becoming offline due to temporary transport problems. -
Page 14: Index
Red Hat Enterprise Linux Procedure 4. Working Around Stale LUNs Determine which link entries in are specific to the stale LUN. mpath /etc/lvm/.cache To do this, run the following command: ls -l /dev/mpath | grep <stale LUN> For example, if is 3600d0230003414f30000203a7bc41a00, the following <stale LUN>...