What is file spanning
Splitting a file
is cutting the data in span parts of desired size.
Usually, this allows a large file to fit on multiple smaller supports
(FD, CD, DVD...) or to fit in multiple email attachments (or upload
chunks) if the file is larger than maximum allowed attachment or upload
size.
In PeaZip you can
select the volume size form a series of pre-set sizes (floppy disk,
typical mail
attachment maximum size, CD,
DVD...) or you can customize it up to byte
level.
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File
split is recommended every time it is needed to fit a large amount of
data in
a mandatory output
size (such as maximum email
attachment limit or media support size), rather than
proceding with trial and error compression attempts hoping to reduce
the output file size under that limit, which may not be possible even
with
trying best compression
algorithms and highest compression settings.
Each
message / media will contain up to the specified amout of data,
guaranteeing the package can be sent / written to disk without errors,
fitting in desired max support / attachment size.
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More online resources: split Unix
command on
Wikipedia, entropy
definition on
Wikipedia, discussion of e-mail
attachment limit
How to split files
PeaZip offers
different, alternative ways to split & join files, or directly
create a spanned archive set:
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Add files and
folders to the archive's layout (i.e.
select it and click Add
button), then
- Click volume size dropdown menu (by
default set on
"Single volume, do not split") in order to split the output to multiple
volumes, chosing from custom or pre-set sizes (recommended email
attachment sizes, CD, DVD, etc): this method allows to combine the
benefits of archiving (consolidating multile input files & folders
into a single output stream), compression (reducing disk occupation
eliminating data redundancy), and file spanning (keeping the output in
volumes smaller than a given maximum size).
- Alternatively, change archive type option
(below
output path option) to
"Split" and set volume size and optional integrity
check algorithm.
OR
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Open PeaZip, chose File manage > File
Tools >
"split file" or "join files"
from
main menu and provide the input file name (provide the first volume of
the set, usually the file with .001 extension
for merging back spanned archives).
OR
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From Windows desktop or file explorer you can
rightclick on a
file and
chose
to split it from PeaZip's entry in system SendTo or Context menu.
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If you are
splitting a
file into multiple removable media, PeaZip will check if the media
has enough free space for storing the volumes, and will be asked you to
provide a new empty media each time the previous one is full.
Hint:
if you need to create a spanned
archive with volumes of different sizes, it is possible to
proceed as described above, and then specify multiple volume sizes in the
"Console" tab of the archive creation screen - then press "Launch task"
to execute.
The -v parameter in the script specifies the volume size as a number
followed by multiplier: k for kilobytes, m for megabbytes, g for
gigabytes, t for terabytes; i.e. -v2g will split each volume at 2 GB in
size.
Adding multiple -v parameters with different sizes, i.e. -v1g -v500m
-v2g, will split the archive in multiple different volume sizes as
specified, in the exact order, with last size being applied to any
extra volume.
In the previous example first volume will be 1 GB in size, second
volume 500 MB, third and any following volume will be 2 GB. |
Purely splitting a file does not
involve compression, that is usually only
marginally efficient on multimedia files, like ie. MP3, OGG and other
audio formats, or AVI, MPEG, DIVX and other video formats.
As said above, if you prefer to combine splitting with compression,
you can add the file(s) to a ZIP or
7Z archive and chose to split (cut) the archive in volumes of a fixed
size,
in order to keep them below the size limits of a support or mail
attachment: this is preferable also when handling multiple large
multimedia
files in
order to store them in a single archive, split in fixed sized volumes,
rather than having to split each file separately.
In this case you can set minimum compression or no
compression ("store" level) to speed up the process avoiding to
compress scarcely compressible data: hints how to improve file
compression, how to
reduce size of graphic files.
PeaZip fully supports, for
splitting and merging, raw split format -
binary data plainly cut in pieces of the exact specified size - that
can be created, also, by utilities like 7-Zip/p7zip, HJSplit, and
"split" Unix command.
This merge files process will re-build the original, larger, file or
archive from
multiple smaller volumes fitting a mandatory maximum size.
Hint: if sent data is
correctly received, as role of thumb, all volumes of the spanned set
should have same size - matching the desired size limit - save the last
volume that will usually be smaller containing only the remaining data
to complete the content - but if a real error detection control is
needed to validate integrity of received data, use file hasing (or
checksum) to verify volumes.
PeaZip can process, only for
merging, WinZip spanned archives (.Z01)
and WinRar spanned archives (.R01, or .partX.rar).
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When you receive a
multipart file or archive, to join the data
back to obtain the original file, move
or copy all the parts of the file in the same
folder before proceeding with extraction
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To
merge spanned volumes, open the
first archive's part with
PeaZip, i.e. doubleclick on the
first volume wich is usually identified with extension .001, .Z01, R01,
.PART1 or similar - please note some times counter may have set to
start from 000 (R00,
Z00) instead.
Now you can extract it with
"Extract" or "Extract all" from
PeaZip's tool bar or context menu, or just drag content from PeaZip to
the system
Alternatively,
righclick on the first volume of the spanned file and
use "Extract" or "Extract
here" PeaZip's entries in system's context menu
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Read more about how to create
spanned 7z archives, how to open and extract
multi-volume rar files, and how to manage
spanned zip files (or how to split
and merge zipx files).
Synopsis: Free file
spanning software (file splitter utility). How to split files and email
attachments in multiple smaller parts, merge / join spanned volumes
chunks with PeaZip, Open Source file splitting application for Linux
and Windows.
Topics: how to split
files, how to join split files, merge spanned archives
PeaZip > FAQ
> Free file splitter, how to use file splitting utility
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