Softpanorama
May the source be with you, but remember the KISS principle ;-)

Contents Bulletin Scripting in shell and Perl Network troubleshooting History Humor

Mount Options in Solaris

News Performing Mounts Recommended links Reference Solaris Mount Tutorial
The "noatime" Option The "logging" Option The "forcedirectio" Option Humor Etc

The "noatime" mount option is useful for running your webserver type of applications, since it's mostly a read-only operation. By eliminating the need to update access times each time a file is accessed, you reduce filesystem activity:

"By default, the file system is mounted with normal access time (atime) recording. If noatime is specified, the file system will ignore access time updates on files, except when they coincide with updates to the ctime or mtime. See stat(2). This option reduces disk activity on file systems where access times are unimportant (for example, a Usenet news spool). noatime turns off access time recording regardless of dfratime or nodfratime."

The "logging" option is a very useful feature that unfortunately was not enabled by default till Solaris 10. By using the "logging" mount option, you enable a filesystem that is journalled on top of the atypical ufs type. From the mount_ufs man page, we see this explanation:

"If logging is specified, then logging is enabled for the duration of the mounted file system. Logging is the process of storing transactions (changes that make up a complete UFS operation) in a log before the transactions are applied to the file system. Once a transaction is stored, the transaction can be applied to the file system later. This prevents file systems from becoming inconsistent, therefore eliminating the need to run fsck. And, because fsck can be bypassed, logging reduces the time required to reboot a system if it crashes, or after an unclean halt. The default behavior is nologging.

The log is allocated from free blocks on the file system, and is sized approximately 1 Mbyte per 1 Gbyte of file system, up to a maximum of 64 Mbytes.

Logging can be enabled on any UFS, including root (/). The log created by UFS logging is continually flushed as it fills up. The log is totally flushed when the file system is unmounted or as a result of the lockfs -f command."

To enable this, simply specify "logging" as an option to mount in /etc/vfstab.

"forcedirectio" option is useful for large files. From the mount_ufs man page, we see this explanation:

"If forcedirectio is specified and supported by the file system, then for the duration of the mount forced direct I/O will be used. If the filesystem is mounted using forcedirectio, then data is transferred directly between user address space and the disk. If the filesystem is mounted using noforcedirectio, then data is buffered in kernel address space when data is transferred between user address space and the disk. forcedirectio is a performance option that benefits only from large sequential data transfers. The default behavior is noforcedirectio."

Recommended Links

Softpanorama Top Visited

Softpanorama Recommended

Everything Solaris Filesystems Tips and Tricks

Why aren't you logging

Getting to know the Solaris filesystem, Part 1 - SunWorld - May 1999


 

Reference

mount_ufs

 
-o specific_options
Specify ufs file system specific options in a comma-separated list with no intervening spaces. If invalid options are specified, a warning message is printed and the invalid options are ignored. The following options are available:
 
noatime
By default, the file system is mounted with normal access time (atime) recording. If noatime is specified, the file system will ignore access time updates on files, except when they coincide with updates to the ctime or mtime. See stat(2). This option reduces disk activity on file systems where access times are unimportant (for example, a Usenet news spool).

noatime turns off access time recording regardless of dfratime or nodfratime.
 

dfratime | nodfratime
By default, writing access time updates to the disk may be deferred (dfratime) for the file system until the disk is accessed for a reason other than updating access times. nodfratime disables this behavior.
 
forcedirectio | noforcedirectio
If forcedirectio is specified and supported by the file system, then for the duration of the mount, forced direct I/O will be used. If the filesystem is mounted using forcedirectio, data is transferred directly between user address space and the disk. If the filesystem is mounted using noforcedirectio, data is buffered in kernel address space when data is transferred between user address space and the disk. forcedirectio is a performance option that is of benefit only in large sequential data transfers. The default behavior is noforcedirectio.
 
global | noglobal
If global is specified and supported on the file system, and the system in question is part of a cluster, the file system will be globally visible on all nodes of the cluster. If noglobal is specified, the mount will not be globally visible. The default behavior is noglobal. The global option is mutually exclusive of the nbmand option, described below.
 
intr | nointr
Allow (do not allow) keyboard interrupts to kill a process that is waiting for an operation on a locked file system. The default is intr.
 
largefiles | nolargefiles
If nolargefiles is specified and supported by the file system, then for the duration of the mount it is guaranteed that all regular files in the file system have a size that will fit in the smallest object of type off_t supported by the system performing the mount. The mount will fail if there are any files in the file system not meeting this criterion. If largefiles is specified, there is no such guarantee. The default behavior is largefiles.

If nolargefiles is specified, mount will fail for ufs if the file system to be mounted has contained a large file (a file whose size is greater than or equal to 2 Gbyte) since the last invocation of fsck on the file system. The large file need not be present in the file system at the time of the mount for the mount to fail; it could have been created previously and destroyed. Invoking fsck (see fsck_ufs(1M)) on the file system will reset the file system state if no large files are present. After invoking fsck, a successful mount of the file system with nolargefiles specified indicates the absence of large files in the file system; an unsuccessful mount attempt indicates the presence of at least one large file.
 

logging | nologging
If logging is specified, then logging is enabled for the duration of the mounted file system. Logging is the process of storing transactions (changes that make up a complete UFS operation) in a log before the transactions are applied to the file system. Once a transaction is stored, the transaction can be applied to the file system later. This prevents file systems from becoming inconsistent, therefore eliminating the need to run fsck. And, because fsck can be bypassed, logging reduces the time required to reboot a system if it crashes, or after an unclean halt. The default behavior is nologging.

The log is allocated from free blocks on the file system, and is sized approximately 1 Mbyte per 1 Gbyte of file system, up to a maximum of 64 Mbytes. Logging can be enabled on any UFS, including root (/). The log created sby UFS logging is continually flushed as it fills up. The log is totally flushed when the file system is unmounted or as a result of the lockfs -f command.

m
Mount the file system without making an entry in /etc/mnttab.
 
nbmand | nonbmand
This option specifies that non-blocking mandatory locking semantics should be allowed on this file system. Non-blocking mandatory locking is disallowed by default. If the file system is mounted with the nbmand option, then applications can use the fcntl(2) interface to place non-blocking mandatory locks on files and the system will enforce those semantics. Enabling this option can cause standards conformant applications to see unexpected errors.

Do not use the nbmand option with /, /var and /usr.

The remount option should not be used to change the nbmand disposition of the file system. The nbmand option is mutually exclusive of the global option, described above.
 

onerror = action
This option specifies the action that UFS should take to recover from an internal inconsistency on a file system. Specify action as panic, lock, or umount. These values cause a forced system shutdown, a file system lock to be applied to the file system, or the file system to be forcibly unmounted, respectively. The default is panic.
 
quota
Quotas are turned on for the file system.
 
remount
Remounts a file system with a new set of options. All options not explicitly set with remount revert to their default values.
rq
Read-write with quotas turned on. Equivalent to rw, quota.
ro | rw
Read-only or read-write. Default is rw.
 
suid | nosuid
Allow or disallow setuid/setgid execution. The default is suid. This option also allows/disallows opening any device-special entries that appear within the filesystem.

This option is highly recommended whenever the file system is shared via NFS with the root= option, because, without it, NFS clients could add setuid programs to the server, or create devices that could open security holes.

-O
Overlay mount. Allow the file system to be mounted over an existing mount point, making the underlying file system inaccessible. If a mount is attempted on a pre-existing mount point without setting this flag, the mount will fail, producing the error "device busy".

 

The mount_ufs command supports the xattr flag, to allow the creation and manipulation of extended attributes. See fsattr(5) for a description of extended attributes. The xattr flag is always on.

mount_nfs




Etc

FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available in our efforts to advance understanding of environmental, political, human rights, economic, democracy, scientific, and social justice issues, etc. We believe this constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit exclusivly for research and educational purposes.   If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner.

Society

Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers :   Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism  : The Iron Law of Oligarchy : Libertarian Philosophy

Quotes

War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda  : SE quotes : Language Design and Programming Quotes : Random IT-related quotesSomerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose BierceBernard Shaw : Mark Twain Quotes

Bulletin:

Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 :  Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method  : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law

History:

Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds  : Larry Wall  : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOSProgramming Languages History : PL/1 : Simula 67 : C : History of GCC developmentScripting Languages : Perl history   : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history

Classic books:

The Peter Principle : Parkinson Law : 1984 : The Mythical Man-MonthHow to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Haterís Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite

Most popular humor pages:

Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor

The Last but not Least


Copyright © 1996-2014 by Dr. Nikolai Bezroukov. www.softpanorama.org was created as a service to the UN Sustainable Development Networking Programme (SDNP) in the author free time. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License. Site uses AdSense so you need to be aware of Google privacy policy. Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.

FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.

This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...

You can use PayPal to make a contribution, supporting hosting of this site with different providers to distribute and speed up access. Currently there are two functional mirrors: softpanorama.info (the fastest) and softpanorama.net.

Disclaimer:

The statements, views and opinions presented on this web page are those of the author and are not endorsed by, nor do they necessarily reflect, the opinions of the author present and former employers, SDNP or any other organization the author may be associated with. We do not warrant the correctness of the information provided or its fitness for any purpose.

Last modified: February 19, 2014