HTAR Manual
Archive Migration Notice
SDSC has migrated from HPSS to the Storage and Archive Manager-Quick File System (SAM-QFS). SDSC staff will be responsible for moving all the data from HPSS to SAM-QFS.
Users are requested NOT to move their own data, as this will significantly delay the migration effort.
More Information
This document is a web version of the UNIX htar manual page, and is provided here for convenience. Please check the online HTAR man page to view the most current documentation.
Last updated: 08/29/2005
htar Command Purpose ------- Manipulates HPSS-resident tar-format archives. Why Use htar? ------------- htar has been optimized for creation of archive files directly in HPSS, without having to go through the intermediate step of first creating the archive file on local disk storage, and then copying the archive file to HPSS via some other process such as ftp or hsi. The program uses multiple threads and a sophisticated buffering scheme in order to package member files into in-memory buffers, while making use of the high-speed network striping capabilities of HPSS. In most cases, it will be significantly faster to use htar to create a tar file in HPSS than to either create a local tar file and then copy it to HPSS, or to use tar piped into ftp (or hsi) to create the tar file directly in HPSS. In addition, htar creates a separate index file, which contains the names and locations of all of the member files in the archive (tar) file. Individual files and directories in the archive can be randomly retrieved without having to read through the archive file. Because the index file is usually smaller than the archive file, it is possible that the index file may reside in HPSS disk cache even though the archive file has been moved offline to tape. Since htar uses the index file for listing operations, it may be possible to list the contents of the archive file without having to incur the time delays of reading the archive file back onto disk cache from tape. It is also possible to create an index file for a tar file that was not originally created by htar or to recreate an index that has been unintentionally deleted.
Syntax
------
htar -{c|t|x|K|X} [-?] -f Archive[-B][-d debuglevel] [-E]
[-L inputlist]
[-F [user@]FTP_server[#port]] [-H opt[:opt...]] [-h]
[-I {IndexFile | .suffix}]
[-M maxfiles] [-m] [-n days] [-o] [-p] [-q]
[-s hpss_server[/port]] [-S Bufsize]
[-T Max Threads] [Filespec | Directory ...] [-v] [-V] [-w]
[-Y [Archive COS ID] [:Index File COS ID]]
The htar command manipulates HPSS-resident archives, or
archives that reside on a remote system (subject to the
restrictions noted below), by writing files to, or retrieving
files from, either HPSS or a remote FTP server.
Files written to HPSS are in the POSIX 1003.1 "tar" format,
and may be retrieved from HPSS (or the remote system),
and read by native "tar" programs.
HTAR can be used to manipulate archive files that reside on a
remote system if the following conditions are met:
1. The HTAR executable must be compiled with this feature
enabled. If not, then the "-F" option will not be recognized.
2. The remote system must be running a version of FTPD that
supports the HPSS parallel transfer protocol.
The local files used by the htar command are represented by the
Filespec parameter. If the Filespec parameter refers to a
directory, then that directory, and, recursively, all files and
directories within it, are referenced as well.
Unlike the standard UNIX "tar" command, there is no default
archive device; the "-f Archive" flag is required.
"Archive" and "Member" files
-----------------------------
Throughout the htar documentation, the term "archive file" is
used to refer to the tar-format file, which is named by the
"-f filename" command line option. The term "member file" is
used to refer to individual files contained within the archive
file.
HTAR Index File ---------------- As part of the process of creating an archive file on HPSS, htar also creates an index file, which is a directory of the files contained in the archive. The Index File includes the position of member files within the archive, so that files and/or directories can be randomly retrieved from the archive without having to read through it sequentially. The index file is usually significantly smaller in size than the archive file, and may often reside in HPSS disk cache even though the archive file resides on tape. All htar operations make use of an index file. It is also possible to create an index file for an archive file that was not created by htar, by using the "Build Index" [-X] function (see below). By default, the index filename is created by adding ".idx" as a suffix to the Archive name specified by the -f parameter. A different suffix or index filename may be specified by the "-I " option, as described below. By default, the Index File is assumed to reside in the same directory as the Archive File. This can be changed by specifying a relative or absolute pathname via the -I option. The Index file's relative pathname is relative to the Archive File directory unless an absolute pathname is specified.
Use of Absolute Pathnames
-------------------------
Although htar does not restrict the use of absolute pathnames
(pathnames that begin with a leading "/") for member files
when the archive is created, it will remove the leading /
when files are extracted from the archive. All extracted
files use pathnames that are relative to the current working
directory.
However, when using the "verify" action (-K), absolute
pathnames are used unless the -Hrelpaths ("relative paths")
option is specifed (see below).
HTAR Consistency File
---------------------
HTAR writes an extra file as the last member file of each
Archive, with a name similar to:
/usr/tmp/HTAR_CF_CHK_64474_982644481
This file is used to verify the consistency of the Archive
File and the Index File. Unless the file is explicitly
specified, HTAR does not extract this file from the Archive
when the -x action is selected. The file is listed,
however, when the -t action is selected.
Tar File Restrictions
-----------------------
When specifying path names that are greater than 100
characters for a file (POSIX 1003.1 USTAR) format, remember
that the path name is composed of a prefix buffer, a /
(slash), and a name buffer.
The prefix buffer can be a maximum of 155 bytes and the name
buffer can hold a maximum of 100 bytes. Since some
implementations of TAR require the prefix and name buffers to
terminate with a null ('\0') character, htar enforces the
restriction that the effective prefix buffer length is 154
characters (+ trailing zero byte), and the name buffer length
is 99 bytes (+ trailing zero byte). If the path name cannot
be split into these two parts by a slash, it cannot be
archived. This limitation is due to the structure of the
tar archive headers, and must be maintained for compliance
with standards and backwards compatibility. In addition,
the length of a destination for a hard or symbolic link
( the 'link name') cannot exceed 100 bytes
(99 characters + zero-byte terminator).
HPSS Default Directories ------------------------ The default directory for the Archive file is the HPSS home directory for the DCE user. An absolute or relative HPSS path can optionally be specified for either the Archive file or the Index file. By default, the Index file is created in the same HPSS directory as the Archive file. For the "Create" action, if the Archive file pathname contains subdirectories that do not already exist, the command will fail unless the "-P" option is used. This option is analogous to the "-p" option for the Un*x "mkdir" command. Local Temporary Directory -------------------------- HTAR makes use of the TMPDIR environment variable when creating temporary files. If TMPDIR is not set in the environment, then "/tmp" is used.
HTAR Command Options
---------------------
Two groups of flags exist for the htar command; "action"
flags and "optional" flags. Action flags specify the
operation to be performed by the htar command, and are
specified by one of the following:
-c, -t, -x, -X, -K
At least one action flag must be selected in order for
the htar command to perform any useful function (note:
in the initial implementation, one and only one action
can be specified per execution).
Filespec
A file specification has one of the following forms:
WildcardPath
or
Pathname
or
Filename
"WildcardPath" is a path specification that includes
standard filename pattern-matching characters, as
specified for the shell that is being used to invoke htar.
The pattern-matching characters are expanded by the shell
and passed to htar as command line arguments.
Note that using wildcard characters for the -t and -x
actions may not work as expected unless there are existing
local files that match the pattern. For example,
htar -xf someFile.tar a*
will only extract files beginning with "a" in "someFile.tar"
that also already exist in the current local working directory.
Action Flags ------------- Action flags defined for htar are as follows: -c Creates a new HPSS-resident archive, and writes the local files specified by one or more File parameters into the archive. Warning: any preexisting archive file will be overwritten without prompting. This behavior mimics that of the AIX tar utility. -t Lists the member files in the order in which they appear in the HPSS- resident archive. Listable output is written to standard output; all other output is written to standard error. -x Extracts the member files specified by one or more File parameters from the archive. If the File parameter refers to a directory, the htar command recursively extracts that directory and all of its subdirectories from the archive. -K Verifies the contents of the archive, based upon the verification level options given by the -Hverify and -Hrelpaths options. If the File parameter is not specified, htar extracts all of the files from the archive. If an archive contains multiple copies of the same file, the last copy extracted overwrites all previously extracted copies. If the file being extracted does not already exist on the system, it is created. If you have the proper permissions, then htar command restores all files and directories with the same owner and group IDs as they have on the HPSS tar file. If you do not have the proper permissions, then files and directories are restored with your owner and group IDs. -X builds a new index file by reading the entire tar file. This operation is used either to reconstruct an index for tar files whose Index File is unavailable (e.g., accidentally deleted), or for tar files that were not originally created by htar.
---------------------------
Options
-? Displays htar's verbose help
-B Displays block numbers as part of the listing
(-t option).
This is normally used only for debugging.
-d debuglevel Sets debug level (0 - N) for htar.
0 disables debug, 1 - n enable progressively higher
levels of debug output. 5 is the highest level;
anything > 5 is silently mapped to 5.
-E If present, specifies that a local file should
be used for the file specified by the "-f Archive"
option. If not specified, then the archive file will
reside in HPSS.
-F [user@]FTP_server[#port] Specifies that the archive
file resides on a remote system that runs a version of
FTPD which supports the HPSS parallel file transfer
protocol. This option is only available if HTAR was
compiled with this capability enabled. If not, then
this option will not be recognized, and will cause a
command line error to be generated.
Any optional parts of the parameter following -F must
not contain any whitespace characters. The remote
username can be specified by the "user@" prefix. The
username can also be of the form "user@realm@" for remote
Kerberos realms; anything preceding the rightmost "@" in
the prefix is assumed to be the username on the remote
system. The remote port to which HTAR should connect can
be specified by the optional "#port" suffix; the default
FTP port (port 21) will be used if a port is not specified.
-f Archive Uses "Archive" as the name of archive to be
read or written. Note: This is a required parameter for
htar, unlike the standard tar utility, which uses a built-in
default name. If the Archive variable specified is -
(minus sign), the tar command writes to standard output or
reads from standard input. If you write to standard output,
the -I option is mandatory, in order to specify an Index
File, which is copied to HPSS if the Archive file is
successfully written to standard output. [Note: this behavior
is deferred - reading from or writing to pipes is not supported
in the initial version of htar].
[-H opt[:opt...]] Specifies HTAR-specific options. Multiple
"-H" parameters may be specified, and multiple colon-separated
options may be specified for each -H. Options may be either
standalone keywords, or may be of the form "opt=value".
The option string must not contain whitespace characters.
Opt may be any of the following:
nostage - specifies that HTAR should try to read the
archive file directly from tape for read operations
such as -x (extract), rather than having HPSS potentially
stage the entire file onto disk cache when it is opened.
This option can be useful when only a small number of files
are being extracted from a large archive. However, misuse of
this option can cause HPSS tape drive resource contention,
and should normally be used only after coordinating with the
site's HPSS administrators.
crc - specifies that HTAR should generate CRC checksums when
creating the archive. For extract (-x), specifying this option
will cause checksums to be regenerated and verified for files
that were added to the archive with checksums enabled. For
build index (-X), this option will cause the archive to be
read, and a checksum to be added to the index. For list (-t)
operations, this option will cause the checksum to be listed
following the object permissions
nocrc - specifies that HTAR should should not generate
CRC checksums when writing to the archive (-c or -X) or
regenerate and compare CRCs (-x).
port=port_number - specifies the port that HTAR should
use when connecting to the HPSS server. This option has
meaning only if the -Hserver option is specified (see below).
rmlocal - specifies that HTAR should attempt to remove local
files on a creation run (-c) after the archive is created and
any post-transfer verification has completed without errors.
Only local files that were successfully copied to the archive
will be removed. Local directories are not affected by this
option, only files and symbolic links.
server=server_host - specifies the HPSS server that HTAR should
connect to when it starts up. This is normally unnecessary,
but can be specified if it is necessary to override the builtin
setting. The "-Hport" option can also be specified to override
the default port to which HTAR connects.
verify=option[,option...] - specifies one or more verification
options that should be performed following successful creation
of the archive (-c), or for the "verify" (-K) command.
Multiple options can be specified by separating them with a
comma, with no whitespace. Options are processed from left to
right, and, in the case of conflicting options, the last one
encountered is used without comment.
Options are as follows:
info - compares tar header info with the corresponding
values in the index
crc/nocrc - enables CRC checking of archive files for which
a CRC was generated when the file was added to the archive
compare/nocompare - enables/disables a byte-by-byte comparison
of archive member files and their local file counterparts.
If -Hrelpaths is not specified, then absolute paths for member
files in the archive will also be treated as absolute local
paths.
0 - enables "info" verification
1 - enables level 0 + "crc" verification
2 - enables level 1 + "compare" verification
all - enables all comparison options (currently,
tar hdr checking, CRC checking, and local file comparisons).
relpaths - specifies that HTAR should use relative paths
instead of absolute paths when comparing the archive and
local member files. This option was intended to provide a
way to compare files with absolute paths on an archive
with member file(s) that were created with relative paths
by a previous "extract" (-x) action.
-h Forces the tar command to follow symbolic links as
if they were normal files or directories. Normally, the tar
command does not follow symbolic links.
-I index_name Specifies the index file name or suffix.
If the first character of the index_name is a period,
then index_name is appended to the Archive name, e.g.
"-f the_htar -I .xndx" would create an index file called
"the_htar.xndx". If the first character is not a period,
then index_name is treated as a relative pathname for the
index file (relative to the Archive file directory) if the
pathname does not start with "/", or an absolute pathname
otherwise.
The default directory for the Index file is the same as for
the Archive file. If a relative Index file pathname is
specifed, then it is appended to the directory path for
the Archive file. For example, if the Archive file resides
in HPSS in the directory "projects/prj/" and is called
files.tar, then an Index file specification of
"-I projects/prj/files.old.idx" would fail, because htar
would look for the file in the directory
"projects/prj/projects/prj". The correct specification
in this case is "-I files.old.idx".
-L InputList Writes the files and directories listed in
the "InputList" file to the archive. Directories named in
the InputList file are treated recursively (Note: this was
not the case for earlier versions of HTAR). Note that
"home directory" notation ("~") is not expanded for pathnames
contained in the InputList file, nor are wildcard characters,
such as "*" and "?".
-M maxfiles Sets the maximum number of member files that
can be contained in the archive when it is initially created.
The default maximum number of member files, and an absolute
maximum number of files, are defined when HTAR is built.
No limit will be enforced if:
- The default maximum number of files was set to a negative
value when HTAR was built, and the -M option is NOT specified,
or - A value less than 0 is specified for the -M option, and
the absolute maximum number of files was also set to a negative
value when HTAR was built.
If the value specified for the -M option exceeds the absolute
maximum value that was defined when HTAR was built, HTAR will
issue a warning message, and use the absolute maximum value.
-m Uses the time of extraction as the modification time.
The default is to preserve the modification time of the files.
Note that the modification time of directories is not
guaranteed to be preserved, since the operating system may
change the timestamp as the directory contents are changed by
extracting other files and/or directories. htar will
explicitly set the timestamp on directories that it extracts
from the Archive, but not on intermediate directories that are
created during the process of extracting files.
-n time Meaningful only for <create> (-c) action. If
specified, only files that have been created or modified
within the specified time will be included in the archive.
This option is intended to simplify the creation of incremental
backups. "time" is specified in one of the following forms:
days
:hours
days:hours
-O If specified, files that are extracted will be
written to standard output. This is normally only useful
when extracting a single file, as there is nothing in the
output stream to mark the end of file.
-o Provides backwards compatibility with older
versions (non-AIX) of the tar command. When this flag is
used for reading, it causes the extracted file to take on
the User and Group ID (UID and GID) of the user running
the program, rather than those on the archive. This is
the default behavior for the ordinary user. If htar is
being run as root, use of this option causes files to be
owned by root rather than the original user.
-O If specified, files that are extracted using
the -x option will be written to standard output.
This is normally only useful when extracting a single
file, as there is nothing in the output stream to mark
the end of file.
-p Says to restore fields to their original modes,
ignoring the present umask. The setuid, setgid, and
tacky bit permissions are also restored to the user with
root user authority.
-P This option is only meaningful for the "create"
action. It causes intermediate subdirectories for the
Archive file pathname to be created if they do not already
exist. NOTE: This option is currently implemented for
HPSS-resident and local-file-resident (-E option) archives.
It has not yet been implemented for FTP-resident archives
(-F option); for FTP-resident archives the option is
accepted, but ignored.
-q "quiet mode" flag. If this option is specified,
htar will not display extraneous messages, such as the
interactive progress messages as it scans directories during
a "create" operation.
-S bufsize Specifies the buffer size to use when
reading or writing the HPSS tar file. The buffer size
can be specified as a value, or as kilobytes by appending
any of "k","K","kb", or "KB" to the value. It can also be
specified as megabytes by appending any of "m" or "M" or
"mb" or "MB" to the value, for example, 23mb.
-T Max Threads Specifies the maximum number of threads
to use when copying local member files to the Archive file.
The default is defined when htar is built; the release value
is 15. The maximum number of threads actually used is
dependent upon the local file sizes, and the size of the I/O
buffers. A good approximation is usually buffer size/average
file size If the -v or -V option is specified, then the maximum
number of local file threads used while writing the Archive
file to HPSS is displayed when the transfer is complete.
-V "Slightly verbose" mode. If selected, file transfer
progress will be displayed in interactive mode. This option
should normally not be selected if verbose (-v) mode is
enabled, as the outputs for the two different options are
generated by separate threads, and may be intermixed on the
output.
-v "Verbose" mode. For each file processed, displays a
one-character operation flag, and lists the name of each file.
The flag values displayed are:
"a" - file was added to the archive
"x" - file was extracted from the archive
"i" - index file entry was created (Build Index operation)
-w Displays the action to be taken, followed by the
file name, and then waits for user confirmation. If the
response is affirmative, the action is performed. If the
response is not affirmative, the file is ignored.
-Y auto | [Archive CosID][:IndexCosID] Specifies the HPSS
Class of Service ID to use when creating a new Archive and/or
Index file. If the keyword "auto" is specified, then the
HPSS "hints" mechanism is used to select the archive COS,
based upon file size. If "-Y cosID" is specified, then
"cosID" is the numeric COS ID to be used for the Archive File.
If "-Y :IndexCosID" is specified, then "IndexCosID" is the
numeric COS ID to be used for the Index File. The default
COS ID (or "auto") is a site-specific option that is defined
when HTAR is built. If both COS IDs are specified, the entire
parameter must be specified as a single string with no
embedded spaces, e.g. "-Y 40:30". This option may also be
specified by the "HTAR_COS" environment variable. The
environment variable is overridden by the -Y command line
option, if both are used.
HTAR Memory Restrictions
-------------------------
When writing to an HPSS archive, the tar command uses a
temporary file (normally in /tmp) and maintains in memory
a table of files; you receive an error message if htar cannot
create the temporary file, or if there is not enough memory
available to hold the internal tables.
Authentication
---------------
HTAR uses Kerberos authentication in order to grant access to
HPSS. For most LLNL systems on which htar is supported, you
obtain the necessary credentials automatically when you login
to the system. If Kerberos credentials are not available when
HTAR is started, it will run the kinit program to obtain them,
and these credentials may be used for subsequent HTAR
invocations, until such time as they expire.
Supported Platforms at LLNL
----------------------------
HTAR is supported on all LC production platforms, and can be
found at /usr/local/bin/htar.
</create>
HTAR Execution Environment
---------------------------
At LLNL, HTAR is actually a wrapper script, which sets the
proper environment variables and then execs the htar executable.
HTAR makes use of the following HPSS environment variables,
if they are available:
HTAR_COS - set to the default COS ID for the archive file,
or the string "auto" to force automatic COS selection based
upon file size hints. This environment variable is overridden
by the -Y command line option.
HPSS_SERVER_HOST - contains the server hostname and optional
port number of the HTAR server.
HPSS_HOSTNAME - contains the hostname or IP address of the
network interface to which HPSS mover(s) should connect
when transferring data. This is overridden by the file
specified in the PFTP_CONFIG_FILENAME environment variable.
The default interface is the one specified by the "hostname"
command. Note that this is often a slow interface, such as
the control ethernet on an IBM SP2.
HPSS_PATH_ETC - pathname of a local directory containing
the HPSS network options file
PFTP_CONFIG_FILENAME - pathname of a file containing the list
of HPSS network interfaces to be used
HTAR also references the following non-HPSS environment
variables:
TMPDIR - used when creating temporary files
HOME - used when searching for the network options file
(normally only used by HPSS system administrators).
Notes: ------- 1. The maximum size of a single Member file within the Archive is approximately 8 GB, due to restrictions in the format of the tar header. HTAR does not impose any restriction on the size of the Archive File when it is written to HPSS; however, space quotas or other system restrictions may limit the size of the Archive File when it is written to a local file (-E option). 2. HTAR will optionally write to a local file; however, it will not write to any file type except "regular files". In particular, it is not suitable for writing to magnetic tape. To write to a magnetic tape device, use the "tar" or "cpio" utility. Exit Status This command returns the following exit values: 0 Successful completion. >0 An error occurred.
Examples
1. To write the file1 and file2 files to a new archive
called "files.tar" in the current HPSS home directory, enter:
htar -cf files.tar file1 file2
2. To write the file1 and file2 files to a new archive
called "files.tar" on a remote FTP server called
"blue.pacific.llnl.gov", creating the tar file in the user's
remote FTP home directory, enter:
htar -cf files.tar -F blue.pacific.llnl.gov file1 file2
2. To extract all files from the project1/src directory
in the Archive file called proj1.tar, and use the time of
extraction as the modification time, enter:
htar -xm -f proj1.tar project1/src
3. To display the names of the files in the out.tar
archive file within the HPSS home directory, enter:
htar -vtf out.tar
Files
/usr/local/bin/htar Specifies the name of the htar
wrapper script.
/usr/local/bin/htar.exe Contains the htar executable.
/tmp/tar* Specifies a temporary file.
Related Information For file archivers: the cat command, dd command, pax command. For HPSS file transfer programs: pftp, nft, hsi File Systems Overview for System Management in AIX Version 4 System Management Guide: Operating System and Devices explains file system types, management, structure, and maintenance. Directory Overview in AIX Version 4 Files Reference explains working with directories and path names. Files Overview in AIX Version 4 System User's Guide: Operating System and Devices provides information on working with files.
Bugs and Limitations: ------------ - There is no way to specify relative Index file pathnames that are not rooted in the Archive file directory without specifying an absolute path. - HTAR does not provide the ability to append, update or remove files.
