*nix Documentation Project
·  Home
 +   man pages
·  Linux HOWTOs
·  FreeBSD Tips
·  *niX Forums

  man pages->Tru64 Unix man pages -> nvfragpg (8)              



NAME    [Toc]    [Back]

       nvfragpg - Displays the pages of an AdvFS frag file

SYNOPSIS    [Toc]    [Back]

       /sbin/advfs/nvfragpg [-v] [-f] frag_id

       /sbin/advfs/nvfragpg [-v] [-f] frag_id page

       /sbin/advfs/nvfragpg volume_id  -b block [-v] [-f]

       /sbin/advfs/nvfragpg domain_id fileset_id -d dump_file

OPTIONS    [Toc]    [Back]

       Specifies  the  logical block number of a disk block on an
       AdvFS volume.  Specifies the name of a file that  contains
       the  output  of this utility.  Displays the frag file free
       list.  Displays all the data in a frag file.

OPERANDS    [Toc]    [Back]

       Specifies a frag file  using  the  following  format:  The
       dump_file  is  a previously-saved copy of a frag file. Use
       the -F option  to  force  the  utility  to  interpret  the
       dump_file  as  a  file name when it has the same name as a
       domain name.  Specifies an AdvFS  file  domain  using  the
       following  format:  By default, the utility opens all volumes
 using block device  special  files.  Specify  the  -r
       option to operate on the raw device (character device special
 file) of the domain  instead  of  the  block  device.
       Specify  the  -D  option to force the utility to interpret
       the name you supply in the domain  argument  as  a  domain
       name.   Specifies an AdvFS volume using the following format:
 Specify the -V option to force the utility to  interpret
  the name you supply in the volume argument as a volume
 name. The volume name argument also can be a  full  or
       partial path name, for example /dev/disk/dsk12a or dsk12a.
       Specifying a partial path name always opens the  character
       device special file.

              Alternatively,  specify  the  volume by using arguments
 for its domain,  domain_id,  and  its  volume
              index  number,  volume_index.   Specifies  an AdvFS
              fileset using the following format: Specify the  -S
              option  to  force the command to interpret the name
              you supply as a fileset name.  Specify the  fileset
              by  entering  either the name of the fileset, fileset,
 or the fileset's tag number,  -T  fileset_tag.
              Specifies the file page number of a file.

DESCRIPTION    [Toc]    [Back]

       Use the nvfragpg utility to display information about frag
       file metadata.

       Each fileset in an AdvFS domain has one frag  file.   Frag
       files  are  collections of file fragments.  The file fragments
 in a frag file are grouped together by file fragment
       size  into 16-page groups.  File fragments of 1 Kb or less
       are collected in one group; file fragments more than 1  Kb
       up  to  2 Kb are collected in another group; and so on, up
       to a group that contains file fragments that are more than
       6 Kb up to 7 Kb.

       The first 1024 bytes of each group in a frag file contains
       the metadata for the file fragments in the group.

       A group is 128 Kb, so a group that collects 1 Kb fragments
       can hold at most 127 fragments, a group that collects 2 Kb
       fragments can hold at most 63 fragments,  and  so  on.   A
       group  that  collects 7 Kb fragments can hold, at most, 18

   Displaying a Summary    [Toc]    [Back]
       The utility can  display  summary  information  about  all
       pages  in a frag file. For example, you can display a summary
 of all the pages of the frag file for domain_1  fileset_1
    by    entering    the    following   command:   #
       /sbin/advfs/nvfragpg domain_1 fileset_1

       The -f option displays which groups are on the  free  list
       for  each frag type.  The -v option gives more information
       for the frag type of each  group.  The  following  command
       displays the type of each group and the free list for each
       frag type: # /sbin/advfs/nvfragpg -v -f domain_1 fileset_1

   Displaying One Frag File Page    [Toc]    [Back]
       You can specify that the utility display the metadata from
       a single group of the frag file by specifying  a  page  in
       the  group. For example, you can display the metadata from
       one group of the frag file for fileset_1  in  domain_1  by
       entering  the  following  command:  # /sbin/advfs/nvfragpg
       domain_1 fileset_1 16

       Because the metadata for the group is only  on  the  first
       page of any 16-page group, the page option is rounded down
       to the next lower multiple of 16.

   Displaying Corrupted Volumes    [Toc]    [Back]
       If an AdvFS volume  has  become  corrupted,  the  metadata
       needed to find the frag file can be missing.  However, you
       can specify a logical block number (for a disk  block)  to
       display  it, forcing the utility to interpret the block as
       frag file metadata.

       For  example, to display the metadata  on  the  frag  page
       that  contains  logical  block  number 1024 on volume 2 of
       AdvFS   domain_1,   use   the   following    command:    #
       /sbin/advfs/nvfragpg domain_1 2 -b 1024

       If  the  specified  block  is not on a page boundary it is
       rounded down.

   Saving a Frag File    [Toc]    [Back]
       Use the utility to read the frag file and save  its  metadata
 to another file.

       For  example, to save the frag file metadata from a domain
       and volume index domain 2 on a file  named  dump_domain.2,
       enter the following command: # /sbin/advfs/nvfragpg domain
       2 -d dump_domain.2

       Later, you can examine the file dump_domain.2 to obtain  a
       summary  of its frag file metadata by entering the following
 command: # /sbin/advfs/nvfragpg dump_domain.2

NOTES    [Toc]    [Back]

       An active domain, which is a domain with one  or  more  of
       its  filesets mounted, has all of its volumes opened using
       block device  special  files.   These  devices  cannot  be
       opened  a second time without first being unmounted.  However,
 the character device special files for  the  volumes
       can be opened more than once while still mounted.

       It  can be misleading to use this utility on a domain with
       mounted filesets because the utility does not  synchronize
       its  read  requests  with AdvFS file domain read and write

       For example, the AdvFS can be writing to the disk  as  the
       utility is reading from the disk.  Therefore, when you run
       the utility, metadata may not have been  flushed  in  time
       for  the  utility to read it, and consecutive reads of the
       same file page may return unpredictable  or  contradictory
       results.  The domain is not harmed.

       To  avoid  this  problem,  unmount all the filesets in the
       domain before using this utility.

RESTRICTIONS    [Toc]    [Back]

       The utility can fail to open a  block  device,  even  when
       there are no filesets mounted for the domain and the AdvFS
       daemon, advfsd is running. The daemon, as it  runs,  activates
  the  domain for a brief time.  If the utility fails
       in this situation, run it again.

EXIT STATUS    [Toc]    [Back]

       The utility returns a 0 (zero) on  success,  otherwise  it
       returns a nonzero value and an error diagnostic.

FILES    [Toc]    [Back]

       Specifies  the  command path.  Specifies the AdvFS volumes
       in domain_name.

SEE ALSO    [Toc]    [Back]

       Commands: nvbmtpg(8), nvlogpg(8), nvtagpg(8),  vfilepg(8),

[ Back ]
 Similar pages
Name OS Title
shfragbf Tru64 Displays frag file information
nvbmtpg Tru64 Display pages of an AdvFS BMT file
vfilepg Tru64 Display pages of an AdvFS file
migrate Tru64 Move a file or file pages to another volume in an AdvFS file domain
nvlogpg Tru64 Displays the log file of an AdvFS domain
showfdmn Tru64 Displays attributes of an AdvFS file domain
advfsstat Tru64 Displays AdvFS performance statistics
showfsets Tru64 Displays information about filesets in an AdvFS domain
showfile Tru64 displays the attributes of AdvFS directories and files
vdf Tru64 Displays disk information for AdvFS domains and filesets
Copyright © 2004-2005 DeniX Solutions SRL
newsletter delivery service