Created
August 11, 2017 16:57
-
-
Save alek-p/365ec175d4fd3ed1572c4fe9d37aac84 to your computer and use it in GitHub Desktop.
Revert ZFS changes by destroying uberblocks
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/usr/bin/python | |
# -*- coding: utf-8 -*- | |
#Script for reverting ZFS changes by destroying uberblocks | |
#Author: Martin Vool | |
#E-mail: mardicas@gmail.com | |
#Version: 0.1 | |
#Date: 16 November 2009 | |
import time | |
import subprocess | |
import sys | |
import os | |
#Default blocksize | |
bs=512 | |
#default total blocks (sorry programming in estonian :-/) | |
suurus=None | |
if len(sys.argv) > 2: | |
for arg in sys.argv: | |
arg=arg.split('=') | |
if len(arg) == 1: | |
file=arg[0] | |
elif arg[0] == '-bs': | |
bs=int(arg[1]) | |
elif arg[0] == '-tb': | |
suurus=int(arg[1]) | |
else: | |
print 'Usage: zfs_revert.py [-bs=n default:n=512 blocksize] \\n [-tb=n total block size in blocks] [file/device] You have to set -tb' | |
exit(1) | |
print int(bs) | |
if suurus == None: | |
print 'Total block size in blocks is undefined' | |
exit(1) | |
#make solaris use gnu grep. | |
if os.uname()[0] == 'SunOS': | |
grep_cmd='ggrep' | |
else: | |
grep_cmd='grep' | |
#to format program output | |
def formatstd(inp): | |
inp=inp.split('\n') | |
ret=[] | |
for line in inp: | |
columns=line.split(' ') | |
nc=[] | |
for c in columns: | |
if c != '': | |
nc.append(c) | |
ret.append(nc) | |
return ret | |
#read blocks from beginning(64mb) | |
a_count=(256*bs) | |
#read blocks from end (64mb) | |
l_skip=suurus-(256*bs) | |
print 'Total of %s blocks'%suurus | |
print 'Reading from the beginning to %s blocks'%a_count | |
print 'Reading from %s blocks to the end'%l_skip | |
#get the uberblocks from the beginning and end | |
yberblocks_a=formatstd(subprocess.Popen('sync && dd bs=%s if=%s count=%s | od -A x -x | %s -A 2 "b10c 00ba" | %s -v "\-\-"'%(bs,file, a_count,grep_cmd,grep_cmd), shell=True, stdout=subprocess.PIPE).communicate()[0]) | |
yberblocks_l=formatstd(subprocess.Popen('sync && dd bs=%s if=%s skip=%s | od -A x -x | %s -A 2 "b10c 00ba" | %s -v "\-\-"'%(bs,file, l_skip,grep_cmd,grep_cmd), shell=True, stdout=subprocess.PIPE).communicate()[0]) | |
yberblocks=[] | |
for p in yberblocks_a: | |
if len(p) > 0: | |
#format the hex address to decmal so dd would eat it. | |
p[0]=(int(p[0], 16)/bs) | |
yberblocks.append(p) | |
for p in yberblocks_l: | |
if len(p) > 0: | |
#format the hex address to decmal so dd would eat it and add the skipped part. | |
p[0]=((int(p[0], 16)/bs)+int(l_skip)) #we have to add until the place we skipped so the adresses would mach. | |
yberblocks.append(p) | |
print '----' | |
#here will be kept the output that you will see later(TXG, timestamp and the adresses, should be 4, might be less) | |
koik={} | |
i=0 | |
for p in yberblocks: | |
if len(p) > 0: | |
if i == 0:#the first output line | |
address=p[0] | |
elif i == 1:#second output line | |
#this is the output of od that is in hex and needs to be reversed | |
txg=int(p[4]+p[3]+p[2]+p[1], 16) | |
elif i == 2:#third output line | |
timestamp=int(p[4]+p[3]+p[2]+p[1], 16) | |
try: | |
aeg=time.strftime("%d %b %Y %H:%M:%S", time.localtime(timestamp)) | |
except: | |
aeg='none' | |
if koik.has_key(txg): | |
koik[txg]['addresses'].append(address) | |
else: | |
koik[txg]={ | |
'txg':txg, | |
'timestamp':timestamp, | |
'htime': aeg, | |
'addresses':[address] | |
} | |
if i == 2: | |
i=0 | |
else: | |
i+=1 | |
keys = koik.keys() | |
keys.sort() | |
while True: | |
keys = koik.keys() | |
keys.sort() | |
print 'TXG\tTIME\tTIMESTAMP\tBLOCK ADDRESSES' | |
for k in keys: | |
print '%s\t%s\t%s\t%s'%(k, koik[k]['htime'],koik[k]['timestamp'],koik[k]['addresses']) | |
try: | |
save_txg=int(input('What is the last TXG you wish to keep?\n')) | |
keys = koik.keys() | |
keys.sort() | |
for k in keys: | |
if k > save_txg: | |
for adress in koik[k]['addresses']: | |
#wrtie zeroes to the unwanted uberblocks | |
format=formatstd(subprocess.Popen('dd bs=%s if=/dev/zero of=%s seek=%s count=1 conv=notrunc'%(bs, file, adress), shell=True, stdout=subprocess.PIPE).communicate()[0]) | |
del(koik[k]) | |
#sync changes to disc! | |
sync=formatstd(subprocess.Popen('sync', shell=True, stdout=subprocess.PIPE).communicate()[0]) | |
except: | |
print '' | |
break |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment