«EMC® VNX™ Series Release 7.0 Managing Volumes and File Systems on VNX™ Manually P/N 300-011-808 REV A01 EMC Corporation Corporate Headquarters: ...»
EMC® VNX™ Series
Managing Volumes and File Systems on VNX™ Manually
Hopkinton, MA 01748-9103
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Published February 2011
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Corporate Headquarters: Hopkinton, MA 01748-9103 Managing Volumes and File Systems on VNX Manually 7.0 Contents Preface
Chapter 1: Introduction
User interface choices
Chapter 2: Concepts
Monitoring and repairing file systems
Supported file system access protocols
File system size guidelines
Volume configuration guidelines
Stripe volume configuration considerations
Chapter 3: Configuring Volumes
Determine storage availability
Create a slice volume
Create a stripe volume
Create a metavolume
Provide storage from a VNX or legacy CLARiiON system to a gateway system
RAID groups and storage characteristics
Add disk volumes to an integrated system
Chapter 4: Configuring File Systems
Create a file system
(Optional) Create a mount point
Mount a file system
(Optional) Create an NMFS
Create a new component file system
Chapter 5: Managing Volumes
Check volume capacity
Rename a volume
Clone a volume
Delete a metavolume or stripe volume
List metavolume information
Delete a metavolume or stripe volume
Delete a slice volume
List slice volume information
Delete a slice volume
Chapter 6: Managing File Systems
Export a file system
Export a file system from a Data Mover for NFS access
Export a file system from a Data Mover for CIFS access
Export an NMFS
List file systems
View the file system configuration information
Managing Volumes and File Systems on VNX Manually 7.0
ContentsList mount points
List mounted file systems
Check disk space capacity for a single mounted file system
Check disk space capacity for all mounted file systems
Check inode capacity
View the inode capacity of a single file system on a Data Mover
View the inode capacity of all file systems on a Data Mover...............67 Extend a file system
Extend replicated file systems
Adjust file system size threshold
Adjust the file system size threshold for all file systems
Adjust the file system size threshold on a single Data Mover..............73 Add an existing file system to an NMFS
Move an NMFS
Rename a file system
Enhance file read/write performance
Turn off read prefetch for a specific file system
Turn off read prefetch for all file systems on a Data Mover.................77 Enable uncached write mechanism
Unmount all file systems from a Data Mover
Unmount all file systems temporarily
Unmount all file systems permanently
Delete a file system or NMFS
Chapter 7: Monitoring and Repairing File Systems
Run a file system check
Start an ACL check on the file system
List file system checks
Display the file system check information on a file system
Display information on all current file system checks
Chapter 8: Troubleshooting
EMC E-Lab Interoperability Navigator
Known problems and limitations
EMC Training and Professional Services
Appendix A: GID Support
Restrictions for GID support
As part of an effort to improve and enhance the performance and capabilities of its product lines, EMC periodically releases revisions of its hardware and software. Therefore, some functions described in this document may not be supported by all versions of the software or hardware currently in use.
For the most up-to-date information on product features, refer to your product release notes.
If a product does not function properly or does not function as described in this document, please contact your EMC representative.
Important: An important note contains information essential to operation of the software.
Note: A note presents information that is important, but not hazard-related.
Note: Do not request a specific support representative unless one has already been assigned to your particular system problem.
Topics included are:
◆ Overview on page 12 ◆ System requirements on page 12 ◆ Restrictions on page 12 ◆ Cautions on page 13 ◆ User interface choices on page 14 ◆ Related information on page 14
Overview The EMC VNX system allows you to create and manage VNX volumes and file systems manually or automatically.
This document explains the manual process for creating, configuring, and managing volumes
and file systems, including:
Managing Volumes and File Systems with VNX AVM provides information on configuring the VNX system to perform these tasks by using Automatic Volume Management (AVM) storage pools.
This document is part of the VNX documentation set and is intended for use by system administrators responsible for creating and managing VNX volumes and file systems manually.
System requirements Table 1 on page 12 describes the EMC® VNX™ series software, hardware, network, and storage configurations.
Cautions If any of this information is unclear, contact your EMC Customer Support Representative
EMC does not recommend spanning a file system (including checkpoint file systems) ◆ across multiple storage systems. All parts of a file system must use the same type of disk storage and be stored on a single storage system. Spanning more than one storage system increases the chance of data loss or data unavailability or both. This is primarily due to the high-availability concern because one storage system could fail while the other continues, making failover difficult. In this case, the targets might not be consistent. In addition, a spanned file system is subject to any performance and feature set differences between storage systems.
Too many files in the root (/) of any file system might impact system performance. For ◆ optimal performance, the number of objects (such as files and subdirectories) should not exceed 500 names.
Review Integration considerations on page 30 if you intend to use file systems with VNX ◆ features such as international character sets, EMC SnapSure™, EMC TimeFinder®/FS, quotas, or an antivirus agent (VEE CAVA).
If you plan to set quotas on a file system to control the amount of space that users and ◆ groups can consume, turn on quotas immediately after creating the file system. Turning on quotas later, when the file system is in use, can cause temporary file system disruption, including slow file system access, for systems that use version 6.0.40 and earlier, and can impact system performance for systems that use version 6.0.41 and later. Using Quotas on VNX contains instructions on turning on quotas and general quotas information.
If your user environment requires international character support (that is, support of ◆ non-English character sets or Unicode characters), configure the system to support this feature before creating file systems. Using International Character Sets on VNX for File contains instructions to support and configure international character support.
If you plan to create TimeFinder/FS (local, NearCopy, or FarCopy) snapshots, do not use ◆ slice volumes (nas_slice) when creating the production file system (PFS). Instead, use the full portion of the disk presented to the system. Using slice volumes for a PFS slated as the source for snapshots wastes storage space and can result in loss of PFS data.
Do not attempt to use Symmetrix TimeFinder tools and utilities with file system copies ◆ created by VNX TimeFinder/FS. It might result in loss of data.
Do not manually edit the nas_db database without consulting EMC Customer Support.
◆ Any changes to this database might cause problems when installing the system.
Permanently unmounting all file systems from a Data Mover must be done with caution ◆ because this operation deletes the contents of the mount table. To reestablish client access to the file systems after this operation, rebuild the mount table by remounting each file system on the Data Mover.
on an unmounted file system, restart the fsck utility on the unmounted file system.
User interface choices The system offers flexibility in managing networked storage based on your support environment and interface preferences. This document describes how to create and manage file systems and their underlying volumes by using the command line interface (CLI). You
can also perform many of these tasks by using one of the following management applications:
The Unisphere software online help contains additional information about managing your system.
Installing Management Applications on VNX for File includes instructions on launching the Unisphere software, and on installing the MMC snap-ins and the ADUC extensions.
The VNX Release Notes contain additional, late-breaking information about system management applications.
Related information Specific information related to the features and functionality described in this document is
Managing a Multiprotocol Environment on VNX ◆ Online VNX man pages ◆ Volumes and file systems information that is related, but is beyond the scope of this document, is included in Managing Volumes and File Systems with VNX AVM.
Other related EMC publications include:
Using FTP and TFTP on VNX ◆ Using MPFS on VNX ◆ EMC VNX documentation on the EMC Online Support website The complete set of EMC VNX series customer publications is available on the EMC Online Support website. To search for technical documentation, go to http://Support.EMC.com. After logging in to the website, click the VNX Support by Product page to locate information for the specific feature required.
VNX wizards Unisphere software provides wizards for performing setup and configuration tasks. The Unisphere online help provides more details on the wizards.
Overview The system offers flexible volumes and file systems management.
Manual volume management allows you to create and aggregate different volume types into usable file system storage that meets your configuration needs. When you create and manage volumes manually, you have greater control over the location of storage allocated to a file system. There are a variety of volume types and configurations from which you can choose to optimize your file system's storage potential. You can divide, combine, and group volumes to meet your specific configuration needs.
You can also manage VNX volumes and file systems without having to create and manage underlying volumes. AVM is a feature that automatically creates and manages usable file system storage. Although AVM is a simple way to create volumes and file systems, automation can limit your control over the location of the storage allocated to a file system.
Managing Volumes and File Systems with VNX AVM provides additional information on AVM capabilities of the system.
File systems A file system is a method of naming and logically organizing files and directories on a storage system. A VNX file system must be created and stored on a metavolume. The metavolume
◆ Expandable storage capacity that might be needed to dynamically expand a file system ◆ The means to form a logical volume that is larger than a single disk A metavolume can include disk volumes, slice volumes, stripe volumes, or other metavolumes.
The VNX system creates different file systems based on how they are used. Table 2 on page 18 lists the types of file system.
Inode An inode is a data structure that stores information on files and the location of file blocks in the NFS file system. The VNX system uses this information to identify if the file is a regular file, a directory, or a symbolic link.
Each file requires at least one inode. Without inodes, you cannot create any new files, even if there is space on the hard drive. The number of bytes per inode (nbpi) specifies the density of inodes in the file system. The nbpi value reflects the expected average size of files in the file system. The nbpi value can be from 2,048 bytes to 8,192 bytes (default). EMC recommends an nbpi value of one inode for every 8,192 bytes. The nbpi value can be changed only when you create a file system.
Monitoring and repairing file systems
Occasionally, a file system might get corrupted if the system is shut down improperly or the disk suffers a minor failure. In these situations, it might be necessary to try to repair the file system by using the fsck utility. Cautions on page 13 provides information on file system behavior during the fsck process.
The fsck utility checks file system consistency on a file system by detecting and correcting file system storage errors.
When a file system corruption is detected during runtime, the Data Mover panics and the restart or failover process starts.
During the restart process, file systems found to be corrupted are not mounted. Run the nas_fsck command manually on these file systems during a suitable time window. You can also use the nas_fsck command to check the status through the Control Station.
When the ufs.skipFsck parameter is set to True (default), the restart process does not run fsck and the corrupted file systems are not mounted. To override this behavior, set this parameter to False. The Parameters Guide for VNX for File provides detailed information on parameters.
When the system begins fsck on a mounted file system, the fsck utility automatically unmounts the file system, runs fsck, and then remounts the file system. The file system is
File systems 19Concepts
unavailable for the duration of the fsck. NFS clients see an "NFS server not responding" message. CIFS clients lose connectivity to the server and must remap shares.