B Documentation Updates

Section 7.4.2, “Partitioning Multipath Devices”

Added issues related to partitioning multipath devices.

Section 13.3.3, “Adding iSCSI Nodes to a Discovery Domain”

Added the -p ip:port option to the following commands:

iscsiadm -m node -t iqn.2006-02.com.example.iserv:systems -p ip:port --op=update --name=node.startup --value=automatic

iscsiadm -m node -t iqn.2006-02.com.example.iserv:systems -p ip:port --op=delete

blacklist_exceptions

Added a link to blacklist_exceptions examples in Section 7.8, “Blacklisting Non-Multipath Devices”.

Section 7.8, “Blacklisting Non-Multipath Devices”

Added examples for using the blacklist_exceptions section to enable multipath for devices blacklisted by the regular expressions used in the blacklist section.

Chapter 17, LVM Volume Snapshots

For clarity, changed “original volume” to “source logical volume”.

Section 17.1, “Understanding Volume Snapshots”

In a Xen host environment, you can use the snapshot function to back up the virtual machine’s storage back-end or to test changes to a virtual machine image such as for patches or upgrades.

Section 17.5, “Using Snapshots for Virtual Machines on a Virtual Host”

This section is new.

Section 17.6, “Merging a Snapshot with the Source Logical Volume to Revert Changes or Roll Back to a Previous State”

If the source logical volume contains a virtual machine image, you must shut down the virtual machine, deactivate the source logical volume and snapshot volume (by dismounting them in that order), issue the merge command, and then activate the snapshot volume and source logical volume (by mounting them in that order). Because the source logical volume is automatically remounted and the snapshot volume is deleted when the merge is complete, you should not restart the virtual machine until after the merge is complete. After the merge is complete, you use the resulting logical volume for the virtual machine.

Section 2.4, “What’s New in SLES 11”

Added information about how to prepare for a SLES 10 SP4 to SLES 11 upgrade if the system device is managed by EVMS.

Section 4.5, “Configuring Logical Volumes”

Added information about thin provisioning of LVM logical volumes.

Section 7.2.6, “Using Multipath with NetApp Devices”

This section is new.

Section 7.2.11.1, “Storage Arrays That Are Automatically Detected for Multipathing”

Updated the list of storage arrays that have a default definition in the /usr/share/doc/packages/multipath-tools/multipath.conf.defaults file.

Section 7.3.4, “Linux multipath(8) Command”

The -r option is new.

Section 7.3.5, “Linux mpathpersist(8) Utility”

This section is new.

Section 7.4.3, “Configuring the Device Drivers in initrd for Multipathing”

Added information about the SCSI hardware handlers for alua, rdac, hp-sw, and emc.

Section 7.7, “Configuring Default Policies for Polling, Queueing, and Failback”

Updated the default values list to annotate the deprecated attributes udev_dir and getuid_callout, the new attribute uid_attribute, and the changed default values for path_selector and max_fds.

Section 7.11.2.1, “Understanding Priority Groups and Attributes”

The default for path_selector changed from round-robin to service-time.

The getuid_callout attribute is deprecated and replaced by the uid_attribute parameter.

Added uid_attribute.

Section 7.14, “Scanning for New Devices without Rebooting”

Section 7.15, “Scanning for New Partitioned Devices without Rebooting”

Section 10.3.3, “Creating a Complex RAID10 with the YaST Partitioner”

This section is new.

Section 1.2.1.4, “Snapshots for the Root File System”

The cleanup frequency is defined in the Snapper configuration for the mount point. Lower the TIMELINE_LIMIT parameters for daily, monthly, and yearly to reduce how long and the number of snapshots to be retained.

Section 1.2.1.9, “Btrfs Quota Support for Subvolumes”

This section is new.

Section 17.2, “Creating Linux Snapshots with LVM”

Added information about thin provisioning for LVM logical volume snapshots.

Section 17.6, “Merging a Snapshot with the Source Logical Volume to Revert Changes or Roll Back to a Previous State”

This section is new.

Section 19.2, “Btrfs Error: No space is left on device”

This section is new.

Section 2.1, “What’s New in SLES 11 SP3”

This section is new.

Section 1.2.3.4, “Ext3 File System Inode Size and Number of Inodes”

This section was updated to discuss changes to the default settings for inode size and bytes-per-inode ratio in SLES 11.

Section 4.6, “Automatically Activating Non-Root LVM Volume Groups”

This section is new.

Section 1.2.1, “Btrfs”

Multiple device support that allows you to grow or shrink the file system. The feature is planned to be available in a future release of the YaST Partitioner.

Section 9.1, “Prerequisites for Using a Software RAID1 Device for the Root Partition”

You need a third device to use for the /boot partition. The devices should be a local device.

Step 4 in Section 9.4, “Creating a Software RAID1 Device for the Root (/) Partition”

Create the /boot partition. The devices should be a local device.

Step 7.b in Section 9.4, “Creating a Software RAID1 Device for the Root (/) Partition”

Under RAID Type, select RAID 1 (Mirroring).

Section 4.1, “Understanding the Logical Volume Manager”

Section 7.2.1.5, “High-Availability Solutions”

Ensure that the configuration settings in the /etc/multipath.conf file on each node are consistent across the cluster.

Section 7.2.3, “Using WWID, User-Friendly, and Alias Names for Multipathed Devices”

When using links to multipath-mapped devices in the /dev/disk/by-id directory, ensure that you specify the dm-uuid* name or alias name, and not a fixed path instance of the device.

Section 7.2.4, “Using LVM2 on Multipath Devices”

To accept both raw disks and partitions for Device Mapper names, specify the path as follows, with no hyphen (-) before mpath:

filter = [ "a|/dev/disk/by-id/dm-uuid-.*mpath-.*|", "r|.*|" ]

Section 7.2.9, “Partitioning Multipath Devices”

Ensure that the configuration files for lvm.conf and md.conf point to the multipath-device names. This should happen automatically if boot.multipath is enabled and loads before boot.lvm and boot.md. Otherwise, the LVM and MD configuration files might contain fixed paths for multipath-devices, and you must correct those paths to use the multipath-device names.

Section 7.9, “Configuring User-Friendly Names or Alias Names”

Before you begin, review the requirements in Section 7.2.3, “Using WWID, User-Friendly, and Alias Names for Multipathed Devices”.

Section 1.4, “Large File Support in Linux”

This section has been updated to be consistent with File System Support and Sizes (http://www.suse.com/products/server/technical-information/#FileSystem) on the SUSE Linux Enterprise Server Technical Information Web site (http://www.suse.com/products/server/technical-information/).

Section 1.5, “Linux Kernel Storage Limitations”

This section is new.

Section 7.6, “Creating or Modifying the /etc/multipath.conf File”

Specific examples for configuring devices were moved to a higher organization level.

Section 7.6.3, “Verifying the Multipath Setup in the /etc/multipath.conf File”

It is assumed that the multipathd daemon is already running with the old (or default) multipath settings when you modify the /etc/multipath.conf file and perform the dry run.

Section 1.2.3.4, “Ext3 File System Inode Size and Number of Inodes”

To allow space for extended attributes and ACLs for a file on Ext3 file systems, the default inode size for Ext3 was increased from 128 bytes on SLES 10 to 256 bytes on SLES11.

Section 7.2.2, “PRIO Settings in multipath-tools-0.4.9”

In SLES 11 SP2, the prio keyword is used to specify the prioritizer, and the prio_args keyword is used to specify its argument if the prioritizer requires an argument.

Multipath Tools 0.4.9 and later uses the prio setting in the defaults{} or devices{} section of the /etc/multipath.conf file. It silently ignores the keyword prio when it is specified for an individual multipath definition in the multipaths{) section.

Section 7.11.2.1, “Understanding Priority Groups and Attributes”

Added information about using prio and prio_args keywords.

Section 7.11.2.1, “Understanding Priority Groups and Attributes”

In SLES 11 SP2, the rr_min_io multipath attribute is obsoleted and replaced by the rr_min_io_rq attribute.

Section 7.19.1, “PRIO Settings for Individual Devices Fail After Upgrading to Multipath 0.4.9”

This section is new.

Section 7.19.2, “PRIO Settings with Arguments Fail After Upgrading to multipath-tools-0.4.9”

This section is new.

Section 7.19.3, “Technical Information Documents”

Fixed broken links.

Section 1.2.1, “Btrfs”

The Btrfs tools package is btrfsprogs.

Section 11.3, “Decreasing the Size of a Software RAID”

Revised the order of the procedures so that you reduce the size of the RAID before you reduce the individual component partition sizes.

Section 4.7, “Tagging LVM2 Storage Objects”

This section is new.

Section 7.7, “Configuring Default Policies for Polling, Queueing, and Failback”

The default getuid path for SLES 11 is /lib/udev/scsi_id.

Section 7.17, “Managing I/O in Error Situations”

Section 7.18, “Resolving Stalled I/O”

In the dmsetup message commands, the 0 value represents the sector and is used when sector information is not needed.

Section 7.11.2.1, “Understanding Priority Groups and Attributes”

Recommendations were added for the no_path_retry and failback settings when multipath I/O is used in a cluster environment.

Section 7.11.2.1, “Understanding Priority Groups and Attributes”

The path-selector option names and settings were corrected:

Section 10.3.1.6, “Offset Layout”

This section is new.

Section 14.4, “Using iSCSI Disks when Installing”

This section is new.

Section 14.5.4, “iSCSI Targets Are Mounted When the Configuration File Is Set to Manual”

This section is new.

Section 1.2.1, “Btrfs”

This section is new.

With SUSE Linux Enterprise 11 SP2, the Btrfs file system is supported as root file system, that is, the file system for the operating system, across all architectures of SUSE Linux Enterprise 11 SP2.

Section 1.2.4, “ReiserFS”

Section 1.2.6, “File System Feature Comparison”

This section is new.

Section 1.4, “Large File Support in Linux”

The values in this section were updated to current standards.

Section 1.6, “Managing Devices with the YaST Partitioner”

This section is new.

Section 5.1, “Guidelines for Resizing”

Section 5.4, “Decreasing the Size of an Ext2 or Ext3 File System”

The resize2fs command allows only the Ext3 file system to be resized if mounted. The size of an Ext3 volume can be increased or decreased when the volume is mounted or unmounted. The Ext2/4 file systems must be unmounted for increasing or decreasing the volume size.

Section 11.2.2, “Increasing the Size of the RAID Array”

The --assume-clean option is new.

Section 7.2.4, “Using LVM2 on Multipath Devices”

Section 7.13, “Configuring Multipath I/O for an Existing Software RAID”

Running dracut is needed only if the root (/) device or any parts of it (such as /var, /etc, /log) are on the SAN and multipath is needed to boot.

Section 7.11.2.1, “Understanding Priority Groups and Attributes”

The default setting for path_grouping_policy changed from multibus to failover in SLES 11.

Section 2.4.13, “Change from Multibus to Failover as the Default Setting for the MPIO Path Grouping Policy”

This section is new.

Section 4.3, “Creating Volume Groups”

LVM2 does not restrict the number of physical extents. Having a large number of extents has no impact on I/O performance to the logical volume, but it slows down the LVM tools.

Tuning the Failover for Specific Host Bus Adapters

This section was removed. For HBA failover guidance, refer to your vendor documentation.

Section 11.3.1, “Decreasing the Size of the File System”

Decreasing the size of the file system is supported when the file system is unmounted.

Section 4.2, “Creating LVM Partitions”

The discussion and procedure were expanded to explain how to configure a partition that uses the entire disk.

The procedure was modified to use the Hard Disk partitioning feature in the YaST Partitioner.

All LVM Management sections

Procedures throughout the chapter were modified to use Volume Management in the YaST Partitioner.

Section 4.8, “Resizing a Volume Group”

This section is new.

Section 4.9, “Resizing a Logical Volume with YaST”

This section is new.

Section 4.11, “Deleting a Volume Group”

This section is new.

Section 4.12, “Deleting an LVM Partition (Physical Volume)”

This section is new.

Section 4.2, “Creating LVM Partitions”

Details were added to the procedure.

Section 7.9, “Configuring User-Friendly Names or Alias Names”

Using user-friendly names for the root device can result in data loss. Added alternatives from TID 7001133: Recommendations for the usage of user_friendly_names in multipath configurations (http://www.suse.com/support/kb/doc.php?id=7001133).

Section 10.3.1.5, “Far Layout”

Errata in the example were corrected.

Section 14.5.1, “Hotplug Doesn’t Work for Mounting iSCSI Targets”

This section is new.

Section 7.2.4, “Using LVM2 on Multipath Devices”

The example in Step 3 was corrected.

Section 7.2.8, “SAN Timeout Settings When the Root Device Is Multipathed”

This section is new.

Section 7.3.2, “Multipath I/O Management Tools”

The file list for a package can vary for different server architectures. For a list of files included in the multipath-tools package, go to the SUSE Linux Enterprise Server Technical SpecificationsPackage Descriptions Web page (http://www.suse.com/products/server/technical-information/), find your architecture and select Packages Sorted by Name, then search on “multipath-tools” to find the package list for that architecture.

Section 7.4.1, “Preparing SAN Devices for Multipathing”

If the SAN device will be used as the root device on the server, modify the timeout settings for the device as described in Section 7.2.8, “SAN Timeout Settings When the Root Device Is Multipathed”.

Section 7.6.3, “Verifying the Multipath Setup in the /etc/multipath.conf File”

Added example output for -v3 verbosity.

Section 7.12.1.1, “Enabling Multipath I/O at Install Time on an Active/Active Multipath Storage LUN”

This section is new.

Section 7.12.1.2, “Enabling Multipath I/O at Install Time on an Active/Passive Multipath Storage LUN”

This section is new.

Step 7.g in Section 14.2.2, “Creating iSCSI Targets with YaST”

In the YaSTNetwork ServicesiSCSI Target function, the Save option allows you to export the iSCSI target information, which makes it easier to provide this information to consumers of the resources.

Section 14.5, “Troubleshooting iSCSI”

This section is new.

Section 8.4, “For More Information”

The Software RAID HOW-TO has been deprecated. Use the Linux RAID wiki (https://raid.wiki.kernel.org/index.php/Linux_Raid) instead.

Section 2.3, “What’s New in SLES 11 SP1”

This section is new.

Section 9.1, “Prerequisites for Using a Software RAID1 Device for the Root Partition”

Corrected an error in the RAID 0 definition..

Section 7.14, “Scanning for New Devices without Rebooting”

Added information about using the rescan-scsi-bus.sh script to scan for devices without rebooting.

Section 7.15, “Scanning for New Partitioned Devices without Rebooting”

Added information about using the rescan-scsi-bus.sh script to scan for devices without rebooting.

Section 7.2.4, “Using LVM2 on Multipath Devices”

Section 7.13, “Configuring Multipath I/O for an Existing Software RAID”

The -f mpath option changed to -f multipath:

mkinitrd -f multipath

prio_callout in Section 7.11.2.1, “Understanding Priority Groups and Attributes”

Multipath prio_callout programs are located in shared libraries in /lib/libmultipath/lib*. By using shared libraries, the callout programs are loaded into memory on daemon startup.

Section 5.1.1, “File Systems that Support Resizing”

The resize2fs utility supports online or offline resizing for the ext3 file system.

Section 2.4.11, “Location Change for Multipath Tool Callouts”

This section is new.

Section 2.4.12, “Change from mpath to multipath for the mkinitrd -f Option”

This section is new.

Section 4.1, “Understanding the Logical Volume Manager”

In the YaST Control Center, select System › Partitioner.

Section 7.8, “Blacklisting Non-Multipath Devices”

The keyword devnode_blacklist has been deprecated and replaced with the keyword blacklist.

Section 7.7, “Configuring Default Policies for Polling, Queueing, and Failback”

Changed getuid_callout to getuid.

Section 7.11.2.1, “Understanding Priority Groups and Attributes”

Changed getuid_callout to getuid.

Section 7.11.2.1, “Understanding Priority Groups and Attributes”

Added descriptions for path_selector of least-pending, length-load-balancing, and service-time options.

Section 2.4.10, “Advanced I/O Load-Balancing Options for Multipath”

This section is new.

Section 7.2.7, “Using --noflush with Multipath Devices”

This section is new.

Section 7.12, “Configuring Multipath I/O for the Root Device”

Added Step 4 and Step 6 for System Z.

Section 7.15, “Scanning for New Partitioned Devices without Rebooting”

Corrected the syntax for the command lines in Step 2.

Section 7.15, “Scanning for New Partitioned Devices without Rebooting”

Step 7 replaces old Step 7 and Step 8.

Section 10.4, “Creating a Degraded RAID Array”

To see the rebuild progress while being refreshed every second, enter

watch -n 1 cat /proc/mdstat 

Section 14.3.1, “Using YaST for the iSCSI Initiator Configuration”

Re-organized material for clarity.

Added information about how to use the settings for the Start-up option for iSCSI target devices:

Section 7.2.11.1, “Storage Arrays That Are Automatically Detected for Multipathing”

Testing of the IBM zSeries device with multipathing has shown that the dev_loss_tmo parameter should be set to 90 seconds, and the fast_io_fail_tmo parameter should be set to 5 seconds. If you are using zSeries devices, you must manually create and configure the /etc/multipath.conf file to specify the values. For information, see Section 7.10, “Configuring Default Settings for zSeries Devices”.

Section 7.3.1, “Device Mapper Multipath Module”

Multipathing is supported for the /boot device in SUSE Linux Enterprise Server 11 and later.

Section 7.10, “Configuring Default Settings for zSeries Devices”

This section is new.

Section 7.12, “Configuring Multipath I/O for the Root Device”

DM-MP is now available and supported for /boot and /root in SUSE Linux Enterprise Server 11.