[2104] | 1 | #!/usr/bin/env python |
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| 2 | """ |
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| 3 | Gathers availability data for the VM host it's running on. |
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| 4 | """ |
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| 5 | |
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| 6 | from subprocess import PIPE, Popen, call |
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| 7 | import sys |
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| 8 | import yaml |
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| 9 | |
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| 10 | # return the amount of memory in kilobytes represented by s |
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| 11 | def parseUnits(s): |
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| 12 | num, unit = s.split(' ') |
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| 13 | return int(num) * {'kb':1, 'mb':1024}[unit.lower()] |
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| 14 | |
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| 15 | def main(argv): |
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[2107] | 16 | """ |
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| 17 | Calculate the amount of memory available for new VMs |
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| 18 | The numbers returned by xm info and xm info -c are in MB |
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| 19 | The numbers in /proc/xen/balloon have nice units |
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| 20 | All math is done in kilobytes for consistency |
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| 21 | Output is in MB |
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[2113] | 22 | |
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| 23 | Bail if /etc/invirt/nocreate exists |
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[2107] | 24 | """ |
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[2113] | 25 | try: |
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| 26 | os.stat('/etc/invirt/nocreate') |
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| 27 | print 0 |
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| 28 | return 0 |
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| 29 | except OSError: |
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| 30 | pass |
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| 31 | |
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[2104] | 32 | p = Popen(['/usr/sbin/xm', 'info'], stdout=PIPE) |
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| 33 | output = p.communicate()[0] |
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| 34 | if p.returncode != 0: |
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| 35 | raise RuntimeError("Command '%s' returned non-zero exit status %d" |
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[2107] | 36 | % ('/usr/sbin/xm info', p.returncode)) |
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[2104] | 37 | xminfo = yaml.load(output, yaml.CSafeLoader) |
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| 38 | |
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| 39 | free_memory = int(xminfo['free_memory']) * 1024 |
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| 40 | |
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[2107] | 41 | ballooninfo = yaml.load(open('/proc/xen/balloon', 'r').read()) |
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[2104] | 42 | currentallocation = parseUnits(ballooninfo['Current allocation']) |
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| 43 | minimumtarget = parseUnits(ballooninfo['Minimum target']) |
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| 44 | |
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| 45 | p = Popen(['/usr/sbin/xm', 'info', '-c'], stdout=PIPE) |
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| 46 | output = p.communicate()[0] |
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| 47 | if p.returncode != 0: |
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| 48 | raise RuntimeError("Command '%s' returned non-zero exit status %d" |
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[2107] | 49 | % ('/usr/sbin/xm info -c', p.returncode)) |
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[2104] | 50 | xminfoc = yaml.load(output, yaml.CSafeLoader) |
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| 51 | |
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| 52 | # In kilobytes |
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| 53 | dom0minmem = int(xminfoc['dom0-min-mem']) * 1024 |
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| 54 | |
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| 55 | dom0_spare_memory = currentallocation - max(minimumtarget, dom0minmem) |
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| 56 | print int((free_memory + dom0_spare_memory)/1024) |
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| 57 | return 0 |
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| 58 | |
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| 59 | if __name__ == '__main__': |
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| 60 | sys.exit(main(sys.argv)) |
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