Class: MDInspector

Inherits:
Object
  • Object
show all
Defined in:
lib/ec2-consistent-backup.rb

Overview

Cheap alternative to using FFI to interface with libdm

Constant Summary collapse

MDFILE = 
"/proc/mdstat"
PERSONALITIES = 
"Personalities :"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(mdfile = MDFILE) ⇒ MDInspector

Returns a new instance of MDInspector.



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# File 'lib/ec2-consistent-backup.rb', line 30

def initialize(mdfile = MDFILE)
  @has_md = false
  if File.exists?(mdfile)
    stat_data = File.open(mdfile).read.split(/\n/)
    personalities_line = stat_data.grep(/#{PERSONALITIES}/)
    if personalities_line =~ /#{PERSONALITIES}(.+)/
      @personalities =  $1
    else
      @has_md = false
    end
    @set_metadata = {}
    stat_data.grep(/^md[0-9]+ : /).each do |md_info|
      if md_info =~ /^md([0-9]+) : active ([^ ]+) (.*)$/
        set_name = "md#{$1}"
        personality = $2
        drives = $3.split(/ /).map{ |i| "/dev/"+i.gsub(/\[[0-9]+\]/,'') }.to_a
        @set_metadata[set_name] =  { :set_name=> set_name, :personality => personality, 
          :drives => drives}
      end
    end
    @has_md = true if @set_metadata.keys.length > 0
  end
end

Instance Attribute Details

#drives ⇒ Object (readonly)

Returns the value of attribute drives.



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# File 'lib/ec2-consistent-backup.rb', line 29

def drives
  @drives
end

#has_md ⇒ Object (readonly)

Returns the value of attribute has_md.



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# File 'lib/ec2-consistent-backup.rb', line 28

def has_md
  @has_md
end

#personalities ⇒ Object (readonly)

Returns the value of attribute personalities.



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# File 'lib/ec2-consistent-backup.rb', line 28

def personalities
  @personalities
end

Instance Method Details

#set(name) ⇒ Object

Returns the information about the MD set @name

Raises:



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# File 'lib/ec2-consistent-backup.rb', line 54

def set(name)
  # Handle "/dev/foobar" instead of "foobar"
  if name =~ /\/dev\/(.*)$/
    name = $1
  end
  return @set_metadata[name] if @set_metadata.has_key?(name)
  raise NoSuchSetException.new(name)
end