LINUS TECH TIPS STORAGE RANKING SCRIPT
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DESCRIPTION
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Generates a text file with the BB code for the forum post as
well as graph images for statistics. Uploads graph images to
a server automatically if one is specified.


DEPENDENCIES
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JSON::XS
File::Spec
Time::Piece
Digest::SHA1
List::Util
Data::Dumper
Net::FTP
GD
GD::Text
GD::Graph



USAGE
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•   Download all necessary files and directories:
        ltt-rankings.pl
        fonts/
        images/
        json/
        Ltt/


•   Enter   the   correct  system   information   into   the
    json/systems.json file.

        ┌─────────────────────┐
    ┌───┤  json/systems.json  ├────────────────────────────┐
    │   └─────────────────────┘                            │
    │                                                      │
    │         ... previous entry ...                       │
    │},                                                    │
    │"system_XXX" : {                                      │
    │    "capacity" : "XX.X",                              │
    │    "case" : "Case Model",                            │
    │    "hdds" : {                                        │
    │         "AAXXXX" : "X",                              │
    │         "BBXYXX" : "Y",                              │
    │         "CCXQXX" : "Z",                              │
    │         "AAXXVX" : "N"                               │
    │    },                                                │
    │    "notes" : null,                                   │
    │    "post" : "post number",                           │
    │    "os" : "Operating System",                        │
    │    "storage_sys" : "Storage System Abbreviation",    │
    │    "username" : "Username on Forum"                  │
    │}                                                     │
    │                                                      │
    └──────────────────────────────────────────────────────┘


    NOTES: 
        ◦   The order in which the entries (case, hdds, ...)
            appear is not relevant.
        ◦   The notes field may or may not be set. If it is
            set, it will be pasted as-is into the post text,
            so  if you  wish to use  BB formatting for that,
            just  enter it like  you would  into  the  forum
            post.
        ◦   The  HDD  descriptors  must  be present  in  the
            json/hdd_types.json  file.  See   below  for  an
            explanation on HDD descriptors.
        ◦   Technically  speaking,  the  capacity  field  is
            optional  at  the  moment,  but  for  historical
            purposes   or  potential   future  use  we  will 
            continue to use it for now.
        ◦   See  below for  a list of  abbreviations for the
            storage_sys and os fields.
        ◦   Make sure to follow JSON syntax:
                -   double quotes,
                -   no commas for last entry in a given data
                    structure.


•   Create a credentials file  json/credentials.json  of the
    following form:

        ┌──────────────────────────┐
    ┌───┤  json/credentials.json   ├───────────────────────┐
    │   └──────────────────────────┘                       │
    │                                                      │
    │{                                                     │
    │    "ftp_user" : "YOUR_FTP_USERNAME",                 │
    │    "ftp_pass" : "PASSWORD",                          │
    │    "ftp_server" : "FTP_SERVER",                      │
    │    "img_server" : "URL_WHERE_IMAGES_WILL_BE"         │
    │}                                                     │
    │                                                      │
    └──────────────────────────────────────────────────────┘

    Alternatively,  one can  omit the  credentials file,  in
    which case the graph images will be merely stored in the
    images/ directory, but will not  be uploaded to a server
    automatically.


•   Run ltt-rankings.pl.


•   The output files will be:
        ◦   ltt-rankings.txt:   The text for the forum post.
        ◦   images/*.png:       The  image   files  for  the
                                statistics plots.


•   Open forum editor, switch to  rich text mode (not raw BB
    code  editing mode). This  is necessary  because if  the
    text is inserted in raw mode, the padding spaces for the
    post  formatting will  be  stripped away  when the  post
    ist  posted.   When  posting  in  rich  text  mode,  the
    padding spaces  are preserved. Copy and paste  text from
    ltt-rankings.txt into forum editor, save post and done.




ABBREVIATIONS
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Abbreviations as  defined by the abbreviations_key  field in
json/constants.json:

WS          Windows Server
WHS         Windows Home Server
SHR         Synology Hybrid RAID
StSp        Storage Spaces
RD          RAID (unspecified if hardware or software)
HwRD        Hardware RAID
SwRD        Software RAID
FlRD        FlexRAID

When  more  abbreviations  are   introduced,  make  sure  to
enter  them   into  the   abbreviations_key  field   in  the
json/constants.json file.




HDD DESCRIPTORS
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HDDs are  classified by vendor  and size, not  by model. The
scheme for the HDD descriptor is:

AAXXXX

Where  "AA" is  a two-letter  code for  the manufacturer  as
defined below, and  "XXXX" is a four-digit code  for the HDD
size.

The vendor codes are:

HT          Hitachi
SG          Seagate
SS          Samsung
TS          Toshiba
US          unspecified vendor
WD          Western Digital Company

The size descriptor is four digits describing ten gigabytes,
so it would look like this for example:

3 TB disk           0300
500 GB disk         0050
1.5 TB disk         0150

and so  on. So a Hitachi drive  of 2 TB capacity  would have
the HDD descriptor of:

HT0200


If an HDD descriptor is used in json/systems.json which does
not  occur in  json/hdd_types.json, the  scrip will  throw a
fatal error and die, notifying the user to amend the records
appropriately.