# 具体命令
umount -lf /data
parted /dev/vdb
e2fsck -f /dev/vdb1
resize2fs /dev/vdb1
mount /dev/vdb1  /data
或
echo "/dev/vdb  /data  ext4  defaults,noatime,nodiratime   0 0" >>/etc/fstab
mount -a

# 具体命令
umount -lf /data
wget -O /tmp/devresize.py http://mirrors.tencentyun.com/install/virts/devresize.py
python /tmp/devresize.py  /dev/vdb
mount /dev/vdb1  /data
或
echo "/dev/vdb  /data  ext4  defaults,noatime,nodiratime   0 0" >>/etc/fstab
mount -a

#!/usr/bin/env python
# coding: utf-8
# FileName: devresize.py
"""
It only handle the following two situations:
1. There is only one primary partiion in the disk with a format of ext2/3/4;
2. The disk is raw with a file system whose format is ext2/3/4.
"""import struct
import array
import fcntl
import time
import sys
import os
import glob
import loggingBLKSSZGET = 0x1268
BLKGETSIZE = 0x1260
BLKRRPART = 0x125f
BLKGETSIZE64 = 0x80041272logger = Nonedef read_ub(data):return struct.unpack('B', data[0])[0]def read_us(data):return struct.unpack('<H', data[0:2])[0]def read_ui(data):return struct.unpack('<I', data[0:4])[0]def read_ul(data):return struct.unpack('<Q', data[0:8])[0]def init_log():global loggerlog_file = 'devresize.log'fmt_file = '%(asctime)s - [%(levelname)-5.5s]- %(filename)s:%(lineno)s - %(message)s'fmt_stream = '[%(levelname)s] - %(message)s'logger = logging.getLogger('devresize')logger.setLevel(logging.DEBUG)file_handler = logging.FileHandler(log_file)file_handler.setLevel(logging.DEBUG)file_handler.setFormatter(logging.Formatter(fmt_file))logger.addHandler(file_handler)stream_handler = logging.StreamHandler()stream_handler.setLevel(logging.INFO)stream_handler.setFormatter(logging.Formatter(fmt_stream))logger.addHandler(stream_handler)class PartitionEntry(object):PartitionTypes = {0x05: "Microsoft Extended",0x83: "Linux",0x85: "Linux Extended"}def __init__(self, data):self.data = dataself.boot_sig = data[0]self.start_head, self.start_sector, self.start_cylinder = (PartitionEntry.get_hsc(data[1:1 + 3]))self.partition_type = read_ub(data[4])self.end_head, self.end_sector, self.end_cylinder = (PartitionEntry.get_hsc(data[5:5 + 3]))self.start_lba = read_ui(data[8:8 + 4])self.sector_num = read_ui(data[12:12 + 4])self.partition_type_name = PartitionEntry.PartitionTypes.get(self.partition_type, "other")@staticmethoddef get_hsc(data):h, s, c = struct.unpack('BBB', data[0:3])c = (c | ((s & 0xC0) << 2))s = (s & 0x3F)return h, s, c@staticmethoddef cal_hsc(sector, hh, ss):s = sector % ss + 1sector /= ssh = sector % hhsector /= hhc = sector & 0xFFs |= (sector >> 2) & 0xC0return h, s, cdef vaild_type(self):return self.partition_type in self.PartitionTypesdef isprimary(self):return self.partition_type == 0x83def __str__(self):if not self.vaild_type():print "%x" % self.partition_typereturn "This isn't a Linux Partition!"return """Start h,s,c: %u %u %uEnd h,s,c: %u %u %uPartition Type Name:%sStart LBA: %uSector Number: %u""" % (self.start_head, self.start_sector, self.start_cylinder,self.end_head, self.end_sector, self.end_cylinder,self.partition_type_name, self.start_lba, self.sector_num)class MBR(object):def __init__(self, data):self.data = dataself.boot_code = data[:446]self.mbr_sig = data[510:512]if self.check_mbr_sig():self.partitions = ([PartitionEntry(data[446 + 16 * i:446 + 16 * (i + 1)])for i in range(0, 4)])else:self.partitions = Noneif self.partitions is not None:self.vaild_part_num = len(filter(lambda x: x.vaild_type(), self.partitions))else:self.vaild_part_num = 0self.device_heads = 0self.device_sectors = 0self.cal_device_hs()def cal_device_hs(self):if self.partitions is not None and self.vaild_part_num == 1:self.device_heads = self.partitions[0].end_head + 1self.device_sectors = self.partitions[0].end_sector & 0x3Fdef check_mbr_sig(self):mbr_sig = read_us(self.mbr_sig)if mbr_sig == 0xAA55:return Trueelse:return Falsedef get_device_size(fd):buf = array.array('c', [chr(0)] * 8)fcntl.ioctl(fd, BLKSSZGET, buf, True)logical_sector_size = read_ul(buf)buf = array.array('c', [chr(0)] * 8)try:fcntl.ioctl(fd, BLKGETSIZE, buf, True)device_size = read_ul(buf) * 512except IOError:fcntl.ioctl(fd, BLKGETSIZE64, buf, True)device_size = read_ul(buf)device_sector_number = device_size / logical_sector_sizelogger.debug('''device_size:%ddevice_sector_number:%dlogical_sector_size:%d''' % (device_size, device_sector_number, logical_sector_size))return device_size, device_sector_number, logical_sector_sizedef backup_mbr(data):bak_name = '/tmp/MBR_%s_bak' % time.strftime("%Y-%m-%d_%X", time.localtime())bak_file = open(bak_name, 'w')bak_file.write(data)bak_file.close()logger.info("Backup MBR to %s" % bak_name)return bak_namedef is_first_start():bak_file_list = glob.glob('/tmp/MBR_%s*bak' % time.strftime("%Y-%m-%d", time.localtime()))return len(bak_file_list) == 0def cal_new_part(part_data, mbr, start_lab, new_end):device_heads, device_sectors = mbr.device_heads, mbr.device_sectorsnew_partition_sector_num = new_end - start_lab + 1begin_h, begin_s, begin_c = PartitionEntry.cal_hsc(start_lab, device_heads, device_sectors)end_h, end_s, end_c = PartitionEntry.cal_hsc(new_end, device_heads, device_sectors)new_part_data = list(part_data[:])new_part_data[1:1 + 3] = list(struct.pack('BBB', begin_h, begin_s, begin_c))new_part_data[5:5 + 3] = list(struct.pack('BBB', end_h, end_s, end_c))new_part_data[0xc:] = list(struct.pack('BBBB', (new_partition_sector_num & 0xff), ((new_partition_sector_num >> 8) & 0xff),((new_partition_sector_num >> 16) & 0xff), ((new_partition_sector_num >> 24) & 0xff)))logger.debug("""Start h,s,c: %u %u %uEnd h,s,c: %u %u %uPartition Type Name:%sStart LBA: %uSector Number: %u""" % (begin_h, begin_s, begin_c,end_h, end_s, end_c,mbr.partitions[0].partition_type_name,mbr.partitions[0].start_lba,new_partition_sector_num))return new_part_data# filesystem type must be ext2/3/4
def check_format(dev):blkid_ret = os.popen('blkid %s' % dev)s = blkid_ret.read()if blkid_ret.close() is not None:return Falsereturn True in [i in s for i in ['ext2', 'ext3', 'ext4']]def part_probe(fd):logger.debug('part_probe')fd.flush()fcntl.ioctl(fd, BLKRRPART)def resize2fs(dev):ret = os.system('e2fsck -f %s' % dev)logger.debug('e2fsck ret is %d' % ret)if ret not in (0, 1):raise RuntimeError('e2fsck failed!!')if ret == 1:logger.info('File system errors corrected')ret = os.system('resize2fs %s' % dev)logger.debug('resize2fs ret is %d' % ret)if ret != 0:raise RuntimeError('resize2fs failed!!')def check_mount(target_dev):  # target_dev is mounted!return os.system('mount | grep "%s " > /dev/null' % target_dev) == 0def write_mbr(fd, mbr_data):fd.seek(0)fd.write(mbr_data)part_probe(fd)fd.close()time.sleep(1)def check_arg(device):return not device[-1].isdigit()def get_disk_path(partation_name):for i, ch in enumerate(os.path.basename(partation_name)[::-1]):if not ch.isdigit():return partation_name[::-1][i::][::-1]logger.error("invalid para %s" % partation_name)raise Exception("invalid para %s" % partation_name)def main():if len(sys.argv) < 2:print "Usage: %s block_device" % sys.argv[0]sys.exit(1)init_log()logger.debug("user input:%s" % ' '.join(sys.argv))device = sys.argv[1]if not check_arg(device):logger.error("The argument should be a whole disk not a partation!like %s" % get_disk_path(device))sys.exit(1)if not os.access(device, os.W_OK):logger.error("Permission denied")sys.exit(1)fd = open(device, 'r+')data = fd.read(512)mbr = MBR(data)device_size, device_sector_number, logical_sector_size = get_device_size(fd)if mbr.vaild_part_num > 1:logger.error("Disk %s have multi partition." % device)sys.exit(1)target_partition = ''resize_part_flag = Trueif mbr.vaild_part_num == 1:  # only one partition, which is the primary partitionif not mbr.partitions[0].isprimary():  # and the filesystem type is ext2/3/4.logger.error("Must be primary partition.")resize_part_flag = Trueif device[-1].isdigit():target_partition = device + 'p1'  # ex: /dev/nbd0 -> /dev/nbd0p1else:target_partition = device + '1'  # ex: /dev/vdb -> /dev/vdb1
        logger.debug(mbr.partitions[0])if mbr.vaild_part_num == 0:  # no partition but whole disk is ext2/3/4resize_part_flag = Falsetarget_partition = devicelogger.debug('target_partition:%s' % target_partition)if not check_format(target_partition):logger.error("Only can process ext2/3/4.")sys.exit(1)if check_mount(target_partition):logger.error("Target device %s must be unmounted." % target_partition)sys.exit(1)logger.info("It will resize (%s).\n""This operation may take from several minutes to several hours, continue? [Y/n]"% target_partition)user_input = raw_input()if user_input.lower() != 'y' and user_input != '':logger.warn("User input neither 'y' nor '[Enter]',exit.")sys.exit(1)if not is_first_start():logger.warn('We find some MBR backup file in /tmp,maybe the MBR is already changed,''do you want to just resize the filesystem? [Y/n]')user_input = raw_input()if user_input.lower() == 'y' or user_input == '':resize_part_flag = Falseif resize_part_flag:logger.debug("Begin to change the partation")if (mbr.partitions[0].start_lba + mbr.partitions[0].sector_num) == device_sector_number:logger.error("No free sectors available.")sys.exit(1)if mbr.partitions[0].sector_num > 0xFFFFFFFF * 512 / logical_sector_size:logger.error("Can't process the partition which have exceeded 2TB.")sys.exit(1)new_start_sector = mbr.partitions[0].start_lbanew_end_sector = device_sector_number - 1if (new_end_sector - new_start_sector + 1) * logical_sector_size > 0xFFFFFFFF * 512:user_input = raw_input("The size of this disk is %.2fTB (%d bytes).\n""But DOS partition table format can not be used on drives for volumes larger than 2TB (2199023255040 bytes).\n""Do you want to resize (%s) to 2TB?[Y/n]"% (round(device_size / 1024.0 / 1024 / 1024 / 1024, 2), device_size,target_partition))if user_input.lower() != 'y' and user_input != '':logger.warn("User input neither 'y' nor '[Enter]',exit.")sys.exit(1)new_end_sector = 0xFFFFFFFF * 512 / logical_sector_size + new_start_sector - 1new_mbr_data = list(data)[:]new_mbr_data[446:446 + 16] = cal_new_part(data[446:446 + 16], mbr,new_start_sector, new_end_sector)backup_mbr(data)try:if resize_part_flag:write_mbr(fd, ''.join(new_mbr_data))resize2fs(target_partition)except Exception, e:logger.error(e)logger.error('Some error occurred!!Maybe you should call the customer service staff.')if __name__ == '__main__':main()