thin_metadata_size: algorithm corrections and output adjustments

This commit is contained in:
Heinz Mauelshagen 2013-06-21 14:33:14 +02:00
parent 0b29c22ba9
commit 8d2ae677ff

View File

@ -7,7 +7,7 @@
#
# Script to calculate device-mapper thin privisioning
# metadata device size based on pool, block size and
# maximum expected thin provisioned devices.
# maximum expected thin provisioned devices and snapshots.
#
require 'optparse'
@ -16,8 +16,6 @@ require 'pathname'
#----------------------------------------------------------------
$prg = Pathname.new($0).basename
$btree_entrysize = 16
$btree_nodesize = 4096
def init_units
units = Hash.new
@ -39,7 +37,7 @@ end
def check_opts(opts)
abort "#{$prg} - 3 arguments required!" if opts.length < 3
abort "#{$prg} - poolsize must be much larger than blocksize" if opts[:poolsize] < opts[:blocksize] * 16
abort "#{$prg} - poolsize must be much larger than blocksize" if opts[:poolsize] < opts[:blocksize]
abort "#{$prg} - maximum number of thin provisioned devices must be > 0" if opts[:maxthins].nil? || opts[:maxthins] == 0
end
@ -51,7 +49,7 @@ def to_sectors(size, units)
abort "#{$prg} - only one unit character allowed!" if a.length > 1 || size.length - s.length > 1
abort "#{$prg} - invalid unit specifier!" if s != a[0]
idx = unit_chars.index(size[a[0].length])
r = size.to_i * units[:factors][idx] / 512
r = size.to_i * units[:factors][idx] / units[:factors][0]
r
end
@ -61,34 +59,31 @@ def parse_command_line(argv, units)
os = OptionParser.new do |o|
o.banner = "Thin Provisioning Metadata Size Calculator.\nUsage: #{$prg} [opts]"
o.on('-b', '--blocksize BLOCKSIZE', String,
"Block size, ie. allocation unit size for thin provisioned devices.") do |bs|
o.on("-b", "--block-size BLOCKSIZE[#{units[:chars]}]", String,
"Block size of thin provisioned devices.") do |bs|
opts[:blocksize] = to_sectors(bs, units)
end
o.on('-s', '--poolsize SIZE', String, "Size of the pool device.") do |ps|
o.on("-s", "--pool-size SIZE[#{units[:chars]}]", String, "Size of the pool device.") do |ps|
opts[:poolsize] = to_sectors(ps, units)
end
o.on('-m', '--maxthins MAXTHINS', Integer, "Size of the pool device.") do |mt|
o.on("-m", "--max-thins #MAXTHINS", Integer, "Maximum sum of all thin devices and snapshots.") do |mt|
opts[:maxthins] = mt
end
o.on('-u', '--units [skKmMgGtTpP]', String, "Output unit specifier.") do |u|
if u =~ /[#{unit_chars}]/
o.on("-u", "--unit [#{units[:chars]}]", String, "Output unit specifier.") do |u|
abort "#{$prg} - output unit specifier invalid." if u.length > 1 || !(u =~ /[#{unit_chars}]/)
opts[:units] = u
else
abort "#{$prg} - output unit specifier invalid."
end
o.on("-n", "--numeric-only", "Output numeric value only.") do
opts[:numeric] = true
end
o.on('-n', '--numeric-only', "Output numeric value only.") do
opts[:numeric] = true || nil
end
o.on('-h', '--help', "Outout this help.") do
o.on("-h", "--help", "Outout this help.") do
puts o
exit
end
end
begin
os.parse(argv)
os.parse!(argv)
rescue OptionParser::ParseError => e
abort "#{$prg} #{e}\n#{$prg} #{os}"
end
@ -97,18 +92,22 @@ def parse_command_line(argv, units)
opts
end
def entries_per_node
btree_node_headersize = 64
($btree_nodesize - btree_node_headersize) / $btree_entrysize
def mappings_per_block
btree_nodesize, btree_node_headersize, btree_entrysize = 4096, 64, 16
(btree_nodesize - btree_node_headersize) / btree_entrysize
end
def estimated_result(opts, units)
idx = opts[:units] ? units[:chars].index(opts[:units]) : 0
r = 1.0 + ((opts[:poolsize] / opts[:blocksize] / entries_per_node) + opts[:maxthins]) * 512 / 8
# double-fold # of nodes, because they aren't fully populated in average
r = (1.0 + ((opts[:poolsize] / opts[:blocksize] / mappings_per_block) * 2 + opts[:maxthins])) * 8 * units[:factors][0] # in bytes!
r /= units[:factors][idx]
tmp = "%.2f" % r
# FIXME: avoid zero decimal places
r = tmp.to_f > 0.0 ? tmp : "%.4e" % r
if tmp.to_f > 0.0
r = tmp.to_i.to_f == tmp.to_f ? tmp.to_i : tmp
else
r = "%.2e" % r
end
r = "#{$prg} estimated metadata area size is #{r} #{units[:strings][idx]}." if !opts[:numeric]
r
end