启动hadoop、hbase需要注意的事项
启动hadoop、hbase进程顺序：
1． 确保磁盘挂载。2.启动hdfs，如果需要mapreduce可以再启动yarn。3.启动hbase。
关闭hadoop、hbase进程顺序：
1. 关闭hbase。2.关闭hdfs。
如何确保磁盘已经挂载：
[root@facenode4 etc]# fdisk -l
Disk /dev/sda: 256.1 GB, 256060514304 bytes
255 heads, 63 sectors/track, 31130 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc8eed33a
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 102400 7 HPFS/NTFS
Partition 1 does not end on cylinder boundary.
/dev/sda2 13 13055 104760320 7 HPFS/NTFS
/dev/sda3 13055 26110 104862720 7 HPFS/NTFS
/dev/sda4 26110 31131 40332632 5 Extended
/dev/sda5 26110 26174 512000 83 Linux
/dev/sda6 26174 31131 39818240 8e Linux LVM
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x7e83782a
Device Boot Start End Blocks Id System
/dev/sdb1 1 121601 976760001 83 Linux
Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc8eed331
Device Boot Start End Blocks Id System
/dev/sdc1 1 121601 976760001 83 Linux
Disk /dev/mapper/VolGroup-lv_root: 20.4 GB, 20388511744 bytes
255 heads, 63 sectors/track, 2478 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/mapper/VolGroup-lv_root doesn't contain a valid partition table
Disk /dev/mapper/VolGroup-lv_swap: 20.4 GB, 20384317440 bytes
255 heads, 63 sectors/track, 2478 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/mapper/VolGroup-lv_swap doesn't contain a valid partition table
上面说明有3块设备可以用于挂载
具体的也可以看下面：
1. 添加磁盘，查看磁盘状况
[root@db1 /]# fdisk -l
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 151 1305 9277537+ 83 Linux
/dev/sda2 1 150 1204843+ 82 Linux swap
Partition table entries are not in disk order
Disk /dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
从查询结果看出，多了一个/dev/sdb的盘
2. 用fdisk 对/dev/sdb 进行分区
[root@db1 /]# fdisk /dev/sdb
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-652, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-652, default 652):
Using default value 652
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
再次查看分区情况，多出来一个/dev/sdb1 的区，这个1是我们在前面指定的，如果我们指定2，就变成 sdb2了。
[root@db1 /]# fdisk -l
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 151 1305 9277537+ 83 Linux
/dev/sda2 1 150 1204843+ 82 Linux swap
Partition table entries are not in disk order
Disk /dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 652 5237158+ 83 Linux
[root@db1 /]#
如果创建完之后，/proc/partitions 查看不到对应的分区，使用parprobe 命令刷新一下就可以了：
[root@web1 ~]# cat /proc/partitions
major minor #blocks name
8 0 175825944 sda
8 1 1020096 sda1
8 2 30716280 sda2
8 3 8193150 sda3
[root@web1 ~]# partprobe /dev/sda
[root@web1 ~]# cat /proc/partitions
major minor #blocks name
8 0 175825944 sda
8 1 1020096 sda1
8 2 30716280 sda2
8 3 8193150 sda3
8 4 135893835 sda4
[root@web1 ~]#
3. 格式化 /dev/sdb1 分区
[root@db1 /]# mkfs -t ext3 /dev/sdb1
mke2fs 1.35 (28-Feb-2004)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
655360 inodes, 1309289 blocks
65464 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1342177280
40 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 30 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
4. 创建目录 并将 /dev/sdb1 挂在到该目录下
[root@db1 /]# ls
backup dev initrd media opt sbin sys usr
bin etc lib misc proc selinux tftpboot var
boot home lost+found mnt root srv tmp
[root@db1 /]# mkdir /u01
[root@db1 /]# ls
backup dev initrd media opt sbin sys u01
bin etc lib misc proc selinux tftpboot usr
boot home lost+found mnt root srv tmp var
[root@db1 /]# mount /dev/sdb1 /u01
5. 验证挂载是否成功
[root@db1 /]# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda1 9131772 7066884 1601012 82% /
none 454256 0 454256 0% /dev/shm
/dev/sdb1 5154852 43040 4849956 1% /backup
6. 设置开机自动挂载
[root@db1 /]# vi /etc/fstab
# This file is edited by fstab-sync - see 'man fstab-sync' for details
LABEL=/ / ext3 defaults 1 1
none /dev/pts devpts gid=5,mode=620 0 0
none /dev/shm tmpfs defaults 0 0
none /proc proc defaults 0 0
none /sys sysfs defaults 0 0
LABEL=SWAP-sda2 swap swap defaults 0 0
/dev/sdb1 /u01 ext3 defaults 0 0
/dev/hdc /media/cdrom auto pamconsole,exec,noauto,m
anaged 0 0
/dev/fd0 /media/floppy auto pamconsole,exec,noauto,m
anaged 0 0