1    Release Notes

This chapter provides information that you must be aware of when working with DIGITAL UNIX 4.0E and TCR 1.5 Patch Kit-0004.

1.1    Required Storage Space

The following storage space is required to successfully install this patch kit:

Base Operating System

TruCluster Software products

1.2    New dupatch Features

Beginning with Revision 26-02 of dupatch, this patch tool utility has been enhanced to provide new features, as described in the following sections. For more information, see the Patch Kit Installation Instructions.

1.2.1    Patch Installation from Multiuser Mode

Patches can now be installed when a system is in multiuser mode.

There are no restrictions on performing patch selection and preinstallation checking in multiuser mode.

However, although you can now install patches in multiuser mode, Compaq recommends that you bring down your system to single-user mode when installing patches that affect the operation of the Tru64 UNIX operating system (or the product you are patching). If your system must remain in multiuser mode, it is recommended that you apply the patches when the system is as lightly loaded as possible.

1.2.2    Patch Installation from a Pseudo-Terminal

Patches can now be installed on the system from a pseudo-terminal (pty) while in single-user mode. To do this, log into the system as root from a remote location and specify that the patches are to be installed in single-user mode. Once all the patch prerequisites are completed, the system will be taken to single-user mode while maintaining the network connection for the root user. The patches will then be installed by the system.

1.2.3    Automatic Kernel Build

If the patches installed indicate that a kernel build is required, dupatch will initiate the kernel build automatically.

Most times a reboot is required to complete the installation and bring the system to a consistent running environment. Certain file types, such as libraries, are not moved into place until you reboot the system.

When installing patches in multiuser mode, you can take one of three options after the kernel build is complete:

1.3    Release Notes for Patch 590.00

This patch provides the following new features for bootable tape.

The updated btcreate(8) reference page sections follow:

1.4    Release Notes for Patch 464.00

The following sections contain reference page updates.

1.4.1    Reference Page Update for cron(8)

  1. Add the following to the DESCRIPTION section:

    When the cron daemon is started with the -d option, a trace of all jobs executed by cron is output to file /var/adm/cron/log.

  2. Add the following to the FILES section:

          /var/adm/cron/cron.deny
              List of denied users
          /var/adm/cron/log
              History information for cron
          /var/adm/cron/queuedefs
              Queue description file for at, batch, and cron

  3. Add queuedefs(4) to the Files: section of RELATED INFORMATION.

1.4.2    New Reference Page for queuedefs(4):

queuedefs(4)                                                     queuedefs(4)
 
 
NAME
 
  queuedefs - Queue description file for at, batch, and cron commands
 
DESCRIPTION
 
  The queuedefs file describes the characteristics of the queues managed by
  cron or specifies other characteristics for cron. Each noncomment line in
  this file describes either one queue or a cron characteristic. Each
  uncommented line should be in one of the following formats.
 
            q.[njobj][nicen][nwaitw]
            max_jobs=mjobs
            log=lcode
 
  The fields in these line are as follows:
 
        q   The name of the queue. Defined queues are as follows:
 
        a   The default queue for jobs started by at
 
        b   The default queue for jobs started by batch
 
        c   The default queue for jobs run from a crontab file
 
        Queues d to z are also available for local use.
 
  njob  The maximum number of jobs that can be run simultaneously in the
        queue; if more than njob jobs are ready to run, only the first njob
        jobs will be run. The others will be initiated as currently running
        jobs terminate.
 
  nice  The nice(1) value to give to all jobs in the queue that are not run
        with a user ID of superuser.
 
  nwait The number of seconds to wait before rescheduling a job that was
        deferred because more than njob jobs were running in that queue, or
        because the system-wide limit of jobs executing (max_jobs) has been
        reached.
 
  mjobs The maximum number of active jobs from all queues that may run at any
        one time. The default is 25 jobs.
 
  lcode Logging level of messages sent to a log file. The default is 4.
        Defined levels are as follows:
 
        level-code   level
 
            0        None
 
            1        Low
 
            2        Medium
 
            3        High
 
            4        Full
 
  Lines beginning with # are comments, and are ignored.
 
EXAMPLES
 
  The following file specifies that the b queue, for batch jobs, can have up
  to 50 jobs running simultaneously; that those jobs will be run with a nice
  value of 20. If a job cannot be run because too many other jobs are
  running, cron will wait 60 seconds before trying again to run it. All other
  queues can have up to 100 jobs running simultaneously; they will be run
  with a nice value of 2, and if a job cannot be run because too many other
  jobs are running, cron will wait 60 seconds before trying again to run it.
 
       b.50j20n60w
 
  The following file specifies that a total of 25 active jobs will be allowed
  by cron over all the queues at any one time, and cron will log all messages
  to the log file. The last two lines are comments that are ignored.
 
       max_jobs=25
       log=4
       # This is a comment
       # And so is this
 
FILES
 
  /var/adm/cron
          Main cron directory
 
  /var/adm/cron/queuedefs
          The default location for the queue description file.
 
RELATED INFORMATION
 
  Commands: at(1), cron(8), crontab(1), nice(1)

1.4.3    Reference Page Update for crontab(1):

    On days when the daylight saving time (DST) changes, cron schedules
    commands differently from normal.
 
    The two rules described below specify cron's scheduling policy
    for days when the DST changes. First some terms will be defined.
 
    An AMBIGUOUS time refers to a clock time that occurs twice
    in the same day because of a DST change (usually on a day during Fall).
 
    A NONEXISTENT time refers to a clock time that does not occur
    because of a DST change (usually on a day during Spring). 
 
    DSTSHIFT refers to the offset that is applied to standard time to
    result in daylight savings time. This is normally one hour, but can be
    any amount of time up to 23 hours and 59 minutes.
 
    The TRANSITION period starts at the first second after the DST shift
    occurs, and ends just before DSTSHIFT time later.
 
    An HOURLY command has a * in the hour field of the crontab entry.
 
 
    RULE 1: (AMBIGUOUS times)
    -------------------------
      A nonhourly command is run only once at the first occurrence
      of an ambiguous clock time.
 
           o  A non-hourly command scheduled for 01:15 and 01:17
              will be run at 01:15 and 01:17 EDT on 10/25/98
              and will not be run at 01:15 or 01:17 EST.
 
      An hourly command is run at all occurrences of an ambiguous time.
 
           o  An hourly command scheduled for *:15 and *:17
              will be run at 01:15 and 01:17 EDT on 10/25/98
              and also at 01:15 and 01:17 EST.
 
 
    RULE 2: (NONEXISTENT times)
    ---------------------------
      A command is run DSTSHIFT time after a nonexistent clock time.
 
      If the command is already scheduled to run at the newly shifted time,
      then the command is run only once at that clock time.
 
           o  A nonhourly command scheduled for 02:15 and 03:15
              will be run once at 03:15 EDT on 4/5/98.
 
           o  A nonhourly command scheduled for 02:15 and 02:17
              will be run once at 03:15 and once at 03:17 EDT on 4/5/98.
 
           o  An hourly command scheduled for *:15 and *:17
              will be run once at 03:15 and once at 03:17 EDT on 4/5/98.
 
 
    Note:
    cron's behavior during the transition period is undefined if the
    DST shift crosses a day boundary, for example when the DST shift
    is 23:29:29->00:30:00 and the transition period is 00:30:00->01:29:59.
 
 
    -------------------------------------------------------------------------
    Here are sample DST change values (for Eastern US time EST/EDT).
    During the transition period, clock time may be either
    nonexistent (02:00-02:59 EST in Spring)
    or ambiguous (01:00-01:59 EDT or EST in Fall).
 
    Spring (April 5, 1998):
      DST shift:         01:59:59 EST Ÿ 03:00:00 EDT
      transition period: 03:00:00 EDT Ÿ 03:59:59 EDT
      DSTSHIFT:          1 hour forwards
 
    Fall (Oct 25, 1998):
      DST shift:         01:59:59 EDT Ÿ 01:00:00 EST
      transition period: 01:00:00 EST Ÿ 01:59:59 EST
      DSTSHIFT:          1 hour backwards
    -------------------------------------------------------------------------
 

1.5    Release Notes for Patch 558.00

The updated reference page sections for lpr(1) follow:

The printer log, lpr.log now reports the creation of files preceded
by a dot (.) in the spooling directories.  Do not amend or delete
these files as the printer subsystem manages their creation and
cleanup.
 
For initial use, DIGITAL recommends that you set the logging level
to lpr.info.  If you have a problem that is escalated to technical
support, the support organization will request lpr.log at the
lpr.debug level.  This is because the DEBUG messages provide a
detailed trace that can only be interpreted by reference to the
source code and lpr.log will simply grow more quickly if DEBUG
messages are logged. The lpr.info level provides a shorter report
of an event, including any network retry messages and unusual
occurences (which are not always errors).  
 
All changes to the status file of a queue, including reports of
any files printed, are reported at the DEBUG level rather than the
INFO level.  This reduces the rate of growth of the file and allows
you to monitor and react to important events more quickly.  The
WARNING level logs events that may need to be attended to, while
the ERROR level logs hard (often fatal) errors.
 
To modify the logging level, edit your /etc/syslog.conf file and
change the lpr line to the required level, such as lpr.info as
follows:
 
          lpr.info      /var/adm/syslog.dated
 
Use the ps command to find the PID for the syslog daemon, and
the following command to re-start syslogd:
 
          # kill -HUP           
 
A new set of log files will be created in /var/adm/syslog.

As previously mentioned, this patch provides support to the BSD lpd(8) print system for Compaq's Advanced Printing Software (APX). This patch allows lpr(1) print jobs to be submitted to the Advanced Print System (APX).

1.6    Release Notes for Patches 534.00 and 321.00

This release notes describes enhanced performance for multithreaded applications for the malloc command.

To make optimum use of the malloc tuning features for performance-sensitive applications, the developer needs to consult the Tuning Memory Allocation section of the malloc(3) reference page.

In addition, three new tuning variables which are particularly important to multithreaded applications are added by this patch. They are described in the following sections.

1.6.1    int __delayed_free = 2;

The variable __delayed_free is used to cause the free() function to use a "delay slot" (of size one). This means that any time you call free, it saves your pointer and actually frees what you last called free with. This is intended to avoid misuse of realloc, where the user frees a pointer and then calls realloc with it. Since the delay slot is shared across all threads, this will not provide reliable protection for multithreaded applications. It also means that it is accessed internally with atomic instruction sequences which can create a bottleneck on multi-CPU systems.

A value of 1 means only delay frees for single-threaded applications. A value of 2 means delay for both single and multithreaded applications. A value of 0 turns this feature off for both classes of applications. All other values cause undefined behavior. It is recommended that all multithreaded applications try to use a value of 1. The default value of 2 will change to 1 in a future release.

1.6.2    int __first_fit = 0;

The variable __first_fit is currently intended only for performance-critical multithreaded applications. It should not be used with single-threaded applications. Its value is used to allow malloc and amalloc to skip up to a larger internal cache list if the optimum node size list is found to be in use by another thread. The allowed values are 0, 1, and 2. Do not use any other value.

A value of 0 disables this feature. A value of 1 allows the next larger list to be used, and a value of 2 allows the next list after that to also be used (three lists in total). Increasing the value of __first_fit can increase both execution speed and memory consumption of multithreaded applications making heavy concurrent use of either malloc functions or the same arena with amalloc functions.

1.6.3    int __max_cache = 15;

The __max_cache variable suggests the number of internal cache (lookaside) lists to be used by malloc and amalloc. Each list contains blocks within the same size range. A larger value of __max_cache causes the internal caching of larger sized blocks. The currently allowable values for this variable are 15, 18, 21, 24, and 27. Do not use any other value. The given values correspond to lists containing nodes up to 632, 1272, 2552, 5112, and 10232 bytes in size, respectively. The maximum length of the lists is determined by the __fast_free_max variable.

Application requests for storage that can be satisfied from a node on a cache list typically happen somewhat faster than those that cannot. Increasing the value of this variable can increase both the execution speed and the memory consumption of an application that allocates nodes in the given size range.

1.7    Release Notes for Patches 320.00 and 321.00

This release note contains the new reference page for amalloc(3).

A new set of memory allocator functions, collectively known as arena malloc, has been added in this patch. The reference page follows:

amalloc(3)                                                amalloc(3)
 
NAME
 
  acalloc, acreate, adelete, afree, amallinfo, amalloc, amallopt,
   amallocblk-size, arealloc - arena memory allocator
 
LIBRARY
 
  Standard C Library (libc.so, libc.a)
 
SYNOPSIS
 
  #include   #include 
  void *acreate (
          void *addr, size_t len, int flags, void *ushdr,
          void *(*grow_func)(size_t, void *));
  int adelete (void *ap);
  void *amalloc (
          size_t size, void *ap);
  void afree (
          void *ptr, void *ap);
  void *arealloc (
          void *ptr, size_t size, void *ap);
  void *acalloc (
          size_t nelem, size_t elsize, void *ap);
  size_t amallocblksize (
          void *ptr, void *ap);
 
The following function definitions are provided only for System V
compatibility:
 
  int amallopt (
          int cmd, int value, void *ap);
  struct mallinfo amallinfo (
          void *ap);
 
DESCRIPTION
 
The amalloc family of routines provides a main memory allocator based on
the malloc(3) memory allocator. This allocator has been extended so that
an arbitrary memory space ("arena") can be set up as an area from which
to allocate memory.
 
Calls to the amalloc family of routines differ from calls to the standard
malloc(3) only in that an arena pointer must be supplied. This arena pointer
is returned by a call to acreate.
 
acreate
    Sets up an area defined as starting at virtual address addr and extending
    for len bytes. Arenas can be either growing or nongrowing.
 
    An arena that is nongrowing is constrained to use only up to len bytes
    of memory. The grow_func parameter should be NULL in this case.
 
    If the arena is "growable", len specifies the original size (minimum of
    1K bytes) and the grow_func parameter specifies a function that will be
    called when the allocator requires more memory.  Note that the original
    buffer addr will be used only for the arena header; the first time more
    memory is required, the "grow" function will be called.  This suggests
    that a minimal (1K) original buffer should be used when setting up a
    growable arena.
 
    The grow function will be called with two parameters: the number of bytes
    required and a pointer to the arena requiring the space. The number of
    bytes requested will always be a multiple of M_BLKSZ (see  header file). 
    The function should return the address of a suitably
    large block of memory.  This block does not need to be contiguous with
    the original arena memory. This block could be obtained from a number of
    sources, such as by mapping in another file (by means of mmap(2)) or by
    calling malloc(3) to enlarge the program's data space.  If the grow
    function decides that it cannot provide any more space, it must return
    (void*)-1.
 
    The ushdr function is currently unused and must be NULL.
 
  adelete
    Causes any resources allocated for the arena (for example, mutexes) to be
    freed. Nothing is done with the arena memory itself.  No additional calls
    to any arena functions can be made after calling adelete.
 
  amalloc
    Returns a pointer to a block of at least size bytes suitably aligned
    for any use.
 
  afree
    Destroys the contents of a block previously allocated by amalloc,
    arealloc, or acalloc and makes this space available for future
    allocation. The argument to afree is a pointer to the block previously
    allocated by amalloc, arealloc, or acalloc.
 
    Undefined results will occur if the space assigned by any of the three
    arena allocator functions is overrun or if some random number is handed
    to afree. It is always permitted to pass NULL to afree.
 
  arealloc
    Changes the size of the block pointed to by ptr to size bytes and
    returns a pointer to the (possibly moved) block.  The contents will
    be unchanged, up to the lesser of the new and old sizes. In the special
    case of a null ptr, arealloc degenerates to amalloc.  A zero size causes
    the passed block to be freed.
 
  acalloc
    Allocates space for an array of nelem elements of size elsize. The space
    is initialized to zeros.
 
  amallocblksize
    Returns the actual size of the block pointed to by ptr.  The returned
    size may be greater than the original requested size.
 
  amallopt
    Provides for control over the allocation algorithm. The available
    values for cmd are defined in the  header file.
 
    The amallopt function can be called repeatedly but, for most commands,
    not after the first small block is allocated.
 
  amallinfo
    Provides instrumentation describing space usage. It returns the mallinfo
    structure defined in the  header file.  The structure is zero
    until after the first space has been allocated from the arena.
 
Each of the allocation routines returns a pointer to space suitably aligned
for storage of any type of object.
 
RETURN VALUES
 
The acreate function returns NULL and sets errno if either len is less than
1K or the MEM_SHARED flag is passed.
 
The amalloc, arealloc, and acalloc functions return a NULL pointer if there
is not enough available memory.  When arealloc returns NULL, the block
pointed to by ptr is left intact. If amallopt is called after any
allocation (for most cmd arguments) or if cmd or value is invalid, nonzero
is returned.  Otherwise, it returns zero.
 
RELATED INFORMATION
 
Function: malloc(3)
 

1.8    Release Notes for Patch 591.00

This release note discusses the I/O Throttling/Smooth Sync patch.

Note

In order to activate I/O Throttling/Smooth Sync, you must also install Patch 568.00.

Note

Smooth Sync is for UNIX File System (UFS) only.

Update your /etc/fstab entries to enable the selected mount options on the selected UFS filesystems.

The new options are smsync2 and throttle. The smsync2 enables an alternate smsync policy in which dirty pages do not get flushed until they have been dirty and idle for the smoothsync age period (default 30 seconds). The default policy is to flush dirty pages after being dirty for the smoothsync age period, regardless of continued modifications to the page. Note that mmaped pages always use this default policy, regardless of the smsync2 setting.

For example, change from:

/dev/rz12e /mnt/test ufs rw 0 2

to:

/dev/rz12e /mnt/test ufs rw,smsync2,throttle 0 2

Note

If you choose not to use smsync2 (which does not affect memory-mapped buffers), remove the smsync2 option from the previous string.

Append to /etc/sysconfigtab any tuning changes. See the TUNING notes that follow for a description of the new io-throttle-shift and io-throttle-maxmzthruput tunables. These tunables are configured in the vfs stanza. The following three lines make up an example:

vfs:

io-throttle-shift = 1

io-throttle-maxmzthruput = 1

Note

If you already have a vfs stanza in your sysconfigtab file, then just add the two io-throttle entries.

To remove this patch, follow these steps:

  1. Edit the /etc/inittab and remove the following smsync lines:

    smsync:23:wait:/sbin/sysconfig -r vfs smoothsync-age=30 > /dev/null 2>&1

    smsyncS:Ss:wait:/sbin/sysconfig -r vfs smoothsync-age=0 > /dev/null 2>&1

  2. Remove any additions to /etc/fstab you may have made (see the previous instructions).

Failure to remove /etc/inittab and /etc/fstab modifications may result in unknown attribute messages, particularly upon system reboot.

TUNING

The purpose of this patch is to minimize system stalls resulting from a heavy system I/O load. This patch introduces a smoothsync approach to writing delayed I/O requests and introduces I/O throttling.

Using smoothsync allows each dirty page to age for a specified time period before getting pushed to disk. This allows more opportunity for frequently modified pages to be found in the cache, which decreases the net I/O load. Also, as pages are enqueued to a device after having aged sufficiently, as opposed to getting flushed by the update daemon, spikes in which large numbers of dirty pages are locked on the device queue are minimized.

I/O throttling further addresses the concern of locking dirty pages on the device queue. It enforces a limit on the number of delayed I/O requests allowed to be on the device queue at any point in time. This allows the system to be more responsive to any synchronous requests added to the device queue, such as a read or the loading of a new program into memory. This may decrease the duration of process stalls for specific dirty buffers, as pages remain available until placed on the device queue.

The relevant tunable variables are as follows:

smoothsync-age

You can adjust this variable from 0 (off) up to 300. This is the number of seconds a page ages before becoming eligible for being flushed to disk via the smoothsync mechanism. A value of 30 corresponds to the guarantee provided by the traditional UNIX update mechanism. Increasing this value increases the exposure of lost data should the system crash, but can decrease net I/O load (to improve performance) by allowing the dirty data to remain in cache longer. In some environments, any data that is not up to date is useless; these are prime candidates for an increased smoothsync-age value. The default value of smoothsync-age is 30.

io-throttle-shift

The greater the number of requests on an I/O device queue, the longer the time required to process those requests and make those pages and device available. The number of concurrent delayed I/O requests on an I/O device queue can be throttled by setting the io-throttle-shift tunable. The throttle value is based on this tunable and the calculated I/O completion rate. The throttle value is proportional to the time required to process the I/O device queue. The correspondences between io-throttle-shift values and the time to process the device queue are:

io-throttle-shift  time to process device queue (sec)
-------------------------------------------------------------------
      -2                   0.25
      -1                   0.5
       0                   1
       1                   2
       2                   4

For example, an io-throttle-shift value of 0 corresponds to accommodating 1 second of I/O requests. The valid range for this tunable is [-4..4] (not all values are shown in the previous table; you can extrapolate). The default value of io-throttle-shift is 1. Environments particularly sensitive to delays in accessing the I/O device might consider reducing the io-throttle-shift value.

io-maxmzthruput

This is a toggle that trades off maximizing I/O throughput against maximizing the availability of dirty pages. Maximizing I/O throughput works more aggressively to keep the device busy, but within the constraints of the throttle. Maximizing the availability of dirty pages is more aggressive at decreasing stall time experienced when waiting for dirty pages.

The environment in which you might consider setting io-maxmzthruput off (0) is one in which I/O is confined to a small number of I/O-intensive applications, such that access to a specific set of pages becomes more important for overall performance than does keeping the I/O device busy. The default value of io-maxmzthruput is 1. Environments particularly sensitive to delays in accessing sets of frequently used dirty pages might consider setting io-maxmzthruput to 0.

1.9    Release Notes for Patch 534.00

The following release notes provide updated information for the quotacheck(8), fsck(8), and fstab(4) reference pages.

quotacheck(8) Reference Page Update

  SYNOPSIS
 
    /usr/sbin/quotacheck [-guv] filesystem ...
 
  OLD>  /usr/sbin/quotacheck -a [-guv] [-l number]
  NEW>  /usr/sbin/quotacheck -a [-guv] [-l number] [-t [no]type]
 
 
  FLAGS
 
  OLD>  -a    Checks all file systems identified in the /etc/fstab file
              as read/write with disk quotas.
 
  NEW>  -a    Checks all UFS and AdvFS file systems identified in the
              /etc/fstab file as read/write with userquota and/or
              groupquota options specified, and a pass number of 1 or
              greater.  If the -t option is specified, only the file systems
              of the specified type will be checked.  Alternatively, if
              type is prefixed with 'no', then the valid file systems in
              the /etc/fstab file that do not have that type will be
              checked.
 
 
  OLD>  -l    number Specifies the number of times to perform disk quota
              checking.
 
  NEW>  -l    number Specifies the maximum number of parallel quotacheck
              processes to run at one time.
 
  NEW>  -t    [no]type
  NEW>        Specifies the file system type.  The supported file systems are 
              as follows:
 
              advfs - Advanced File System (AdvFS)
 
              ufs - UNIX File System (UFS)
 
              See fstab(4) for a description of file system types.  If
              the 'no' prefix is used, all of the previous file types
              except the one specified are checked.
 
              Note, the -t flag is only valid when used with the -a flag.
 
  DESCRIPTION
 
  OLD>  The quotacheck command examines each specified file system, builds a
        table of current disk usage, and compares this table against that
        stored in the disk quota file for the file system.  If any
        inconsistencies are detected, both the quota file and the current
        system copy of the incorrect quotas are updated.  Each file system
        must be mounted with quotas enabled.
 
  NEW>  The quotacheck command examines each specified file system, builds a
        table of current disk usage, and compares this table against that
        stored in the disk quota file for the file system.  If any
        inconsistencies are detected, both the quota file and the current
        system copy of the incorrect quotas are updated.
 
  OLD>  The quotacheck command runs parallel passes on file systems using
        the number specified in the fsck field of the file system's entry in
        the /etc/fstab file.  The quotacheck command only checks file
        systems with pass number 1 or higher in the fsck field.  A file
        system with no pass number is not checked.
 
  NEW>  The quotacheck -a command runs parallel passes on file systems using
        the number specified in the /etc/fstab pass number field.  The
        quotacheck command only checks file systems with pass number 1 or
        higher in the fsck field.  A file system with no pass number is
        not checked.
 
  OLD>  For both UFS file systems and AdvFS filesets, you should assign the
        root file system a fsck field value of 1, and a value of 2 or
        higher to other file systems.  See fstab(4) for more information.
 
  NEW>  For both UFS file systems and AdvFS filesets, you should assign the
        root file system a pass number of 1, and a value of 2 or higher
        to other file systems.  See fstab(4) for more information.
 
  OLD>  The quotacheck command checks only file systems that have the
        userquota or groupquota option specified in the /etc/fstab file.
 
  NEW>  The quotacheck command checks only file systems that are mounted.
        UFS file systems must also have userquota and/or groupquota options
        specified in the /etc/fstab file.  The userquota and groupquota
        options are only needed for AdvFS file systems if quotas are
        actually going to be enforced or if they are to be selected with the 
        -a option.

fsck(8) Reference Page Update

OLD>  When the system boots, the fsck program is automatically
        run with the -p flag.  The program reads the /etc/fstab file to
        determine which file systems to check.  Only partitions that 
        are specified in the fstab file as being mounted ``rw'' or 
        ``ro'' and that have a nonzero pass number are checked.  
        File systems that have a pass number 1 
        (usually only the root file system) are checked one at a time.  
        When pass 1 completes, all the remaining file systems are
        checked, with one process running per disk drive.
 
  NEW>  When the system boots, the fsck program is automatically
        run with the -p flag.  The program reads the /etc/fstab file to
        determine which file systems to check.  Only partitions that 
        are specified in the fstab file as being mounted ``rw'' or 
        ``ro'' and that have a nonzero pass number are checked.  
        File systems that have a pass number 1
        (usually only the root file system) are checked one at a time.  
        When pass 1 completes, the remaining pass numbers are processed
        with one parallel fsck process running per disk drive in the 
        same pass.
 
  NEW>  The per disk drive logic is based on the /dev/disk/dsk0a
        syntax where different partition letters are treated as being 
        on the same disk drive.  Partitions layered on top of an LSM 
        device may not follow this naming convention.  In this case 
        unique pass numbers in /etc/fstab may be used to sequence fsck 
        checks.

fstab(4) Reference Page Update

 userquota [=filename] and groupquota [=filename]
 
        If quotas are to be enforced for users or groups,
        one or both of the options must be specified.  If 
        userquota is specified, user quotas are to be enforced.  
        If groupquota is specified, group:
 
  OLD>  quotas are to be enforced.
 
  NEW>  quotas are to be enforced (see quotaon and quotaoff(8)).
 
 
  OLD>  For UFS  file systems, the sixth field, (fsck), is used by 
        the fsck command to determine the order in which file system
        checks are done at reboot time.  For the root file system, 
        specify 1 in the fsck field. For other UFS file systems, 
        specify 2 or higher in the fsck field.  Each UFS file system 
        should have a unique fsck value.
 
  NEW>  For UFS  file systems, the sixth field, (pass number), is
        used by the fsck and quotacheck commands to determine the 
        order in which file system checks are done at reboot time.  
        For the root file system, specify 1 in the fsck field.  For 
        other UFS file systems specify 2 or higher in the pass number 
        field.
 
  OLD>  For AdvFS filesets, the  sixth field is a pass number
        field that allows the quotacheck command to perform all of the
        consistency checks needed for the fileset.  For the root file 
        system, specify 1 in the fsck field.  Each AdvFS fileset in 
        an AdvFS file domain should have a unique fsck value, which 
        should be 2 or higher.
 
  NEW>  For AdvFS filesets, the  sixth field is a pass number
        field that allows the quotacheck command to perform all of the
        consistency checks needed for the fileset.  For the root file 
        system, specify 1 in the fsck field.  For other AdvFS file 
        systems specify 2 or higher in the pass number field.
 
  OLD>  File systems that are on the same disk are checked
        sequentially, but file systems on different disks are 
        checked at the same time to utilize parallelism available 
        in the hardware.  If the sixth field is not present or zero, 
        a value of 0 is returned and the fsck command
        assumes that the file system does not need to be checked.
 
  NEW>  File systems that are on the same disk or domain are checked
        sequentially, but file systems on different disks or
        domains but with the same or greater than 1 pass number are 
        checked at the same time to utilize parallelism available in 
        the hardware.  When all the file systems in a pass have 
        completed their checks, then the file systems with the 
        numerically next higher pass number will be processed.
 
  NEW>  The UFS per disk drive logic is based on the
        /dev/disk/dsk0a syntax where different partition letters 
        are treated as being on the same disk drive.  Partitions 
        layered on top of an LSM device may not follow this naming 
        convention.  In this case unique pass numbers may be used
        to sequence fsck and quotacheck processing.  If the sixth 
        field is not present or 0, a value of 0 is returned
        and the fsck command assumes that the file system does
        not need to be checked.

1.10    Release Notes for Patch 581.00

If the system configurable parameter, lsm:lsm_V_ROUND_enhanced is set (value = 1), the enhanced read round robin policy is activated. This new policy stores the last block accessed by the previous IO request. When returning for another block in round robin (V_ROUND) mode, that value is compared to the current read. If it is within a predefined, user-configurable value (lsm:lsm_V_ROUND_enhance_proximity), then the same plex is used. Otherwise the next plex is used as for a normal round robin behavior.

The two new additional tunable parameters are lsm_V_ROUND_enhanced set to 1 by default (V_ROUND read is activated) and lsm_V_ROUND_enhance_proximity is set to 512 by default.

Append any tuning changes to /etc/sysconfigtab. Refer to the TUNING notes below for a description of the new lsm_V_ROUND_enhanced and lsm_V_ROUND_enhance_proximity tunables. These tunables are configured in the lsm stanza. The following three lines are an example: 

lsm:
	lsm_V_ROUND_enhanced = 1
	lsm_V_ROUND_enhance_proximity = 1024

Note

If you already have an lsm stanza in your sysconfigtab file, then just add the two lsm_V_ROUND entries.

TUNING

The purpose of this patch is to increase performance with sequential reads. This patch introduces a new enhanced round robin mode where the last block read is now compared to the next block to read, and a check is added to see if last block number-next block number is less than or equal to lsm_V_ROUND_enhance_proximity. If it is, read from the same plex. This attempts to hit the disk cache, thereby increasing performance.

The relevant tunable variables are:

lsm_V_ROUND_enhanced This variable activates the new enhanced round robin read policy if it is set to TRUE (1). Otherwise the policy is deactivated.

DEFAULT = 1

lsm_V_ROUND_enhance_proximity This variable provides the proximity in which the last read and new read most lie in an attempt to read data from the disk's cache by reading from the same plex. The variable can be adjusted from 0 to 4096.

DEFAULT = 512