分类目录归档：Linux

ext3/ext4 超级块修复

发表于 2016 年 11 月 12 日 由 惜分飞

创建ext4文件系统

[root@localhost ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
1310720 inodes, 5242624 blocks
262131 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2153775104
160 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

[root@localhost ~]# mkdir /sdb
[root@localhost ~]# mount /dev/sdb1 /sdb
[root@localhost ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/ol-root   36G  4.0G   32G  12% /
devtmpfs             1.8G     0  1.8G   0% /dev
tmpfs                1.8G     0  1.8G   0% /dev/shm
tmpfs                1.8G  8.9M  1.8G   1% /run
tmpfs                1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/sda1            497M  195M  303M  40% /boot
tmpfs                369M     0  369M   0% /run/user/0
/dev/sdb1             20G   45M   19G   1% /sdb

准备测试数据

[root@localhost sdb]# cd /etc/sysctl.d/
[root@localhost sysctl.d]# ls
99-sysctl.conf
[root@localhost sysctl.d]# cp 99-sysctl.conf /sdb
[root@localhost sysctl.d]# more 99-sysctl.conf
# System default settings live in /usr/lib/sysctl.d/00-system.conf.
# To override those settings, enter new settings here, or in an /etc/sysctl.d/<name>.conf file
#
# For more information, see sysctl.conf(5) and sysctl.d(5).

破坏ext4文件系统

[root@localhost ~]#  dd if=/dev/zero of=/dev/sdb1 bs=1024 count=5
5+0 records in
5+0 records out
5120 bytes (5.1 kB) copied, 0.00270838 s, 1.9 MB/s
[root@localhost ~]# mount /dev/sdb1 /sdb
mount: unknown filesystem type '(null)'

日志报错

[ 8868.362628] sd 32:0:1:0: [sdb] Cache data unavailable
[ 8868.362632] sd 32:0:1:0: [sdb] Assuming drive cache: write through
[ 8868.363714]  sdb: sdb1
[ 8868.390297] sd 32:0:1:0: [sdb] Cache data unavailable
[ 8868.390301] sd 32:0:1:0: [sdb] Assuming drive cache: write through
[ 8868.391462]  sdb: sdb1
[ 8900.130143] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null)
[ 8900.130163] SELinux: initialized (dev sdb1, type ext4), uses xattr
[ 8902.803966] sdb1: WRITE SAME failed. Manually zeroing.

fsck修复

[root@localhost ~]# fsck -t ext4 /dev/sdb1
fsck from util-linux 2.23.2
e2fsck 1.42.9 (28-Dec-2013)
ext2fs_open2: Bad magic number in super-block
fsck.ext4: Superblock invalid, trying backup blocks...
/dev/sdb1 was not cleanly unmounted, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Free blocks count wrong for group #1 (31740, counted=31739).
Fix<y>? yes
Free blocks count wrong (5116302, counted=5116301).
Fix<y>? yes
Free inodes count wrong for group #0 (8181, counted=8180).
Fix<y>? yes
Free inodes count wrong (1310709, counted=1310708).
Fix<y>? yes

/dev/sdb1: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sdb1: 12/1310720 files (0.0% non-contiguous), 126323/5242624 blocks

测试修复结果

[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# mount /dev/sdb1 /sdb
[root@localhost ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/ol-root   36G  4.0G   32G  12% /
devtmpfs             1.8G     0  1.8G   0% /dev
tmpfs                1.8G     0  1.8G   0% /dev/shm
tmpfs                1.8G  8.9M  1.8G   1% /run
tmpfs                1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/sda1            497M  195M  303M  40% /boot
tmpfs                369M     0  369M   0% /run/user/0
/dev/sdb1             20G   45M   19G   1% /sdb
[root@localhost ~]# cd /sdb
[root@localhost sdb]# ls
99-sysctl.conf  lost+found
[root@localhost sdb]# more 99-sysctl.conf
# System default settings live in /usr/lib/sysctl.d/00-system.conf.
# To override those settings, enter new settings here, or in an /etc/sysctl.d/<name>.conf file
#
# For more information, see sysctl.conf(5) and sysctl.d(5).

ext4文件系统修复

[root@localhost ~]# mkfs.ext3 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
1310720 inodes, 5242624 blocks
262131 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
160 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

[root@localhost ~]# mount /dev/sdb1 /sdb
[root@localhost ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/ol-root   36G  4.0G   32G  12% /
devtmpfs             1.8G     0  1.8G   0% /dev
tmpfs                1.8G     0  1.8G   0% /dev/shm
tmpfs                1.8G  8.9M  1.8G   1% /run
tmpfs                1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/sda1            497M  195M  303M  40% /boot
tmpfs                369M     0  369M   0% /run/user/0
/dev/sdb1             20G   45M   19G   1% /sdb
[root@localhost ~]# dd if=/dev/zero of=/dev/sdb1 bs=1024 count=5
5+0 records in
5+0 records out
5120 bytes (5.1 kB) copied, 0.0138915 s, 369 kB/s
[root@localhost ~]# fsck -t ext3 /dev/sdb1
fsck from util-linux 2.23.2
e2fsck 1.42.9 (28-Dec-2013)
ext2fs_open2: Bad magic number in super-block
fsck.ext3: Superblock invalid, trying backup blocks...
/dev/sdb1 was not cleanly unmounted, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information

/dev/sdb1: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sdb1: 11/1310720 files (0.0% non-contiguous), 126322/5242624 blocks
[root@localhost ~]# mount /dev/sdb1 /sdb
[root@localhost ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/ol-root   36G  4.0G   32G  12% /
devtmpfs             1.8G     0  1.8G   0% /dev
tmpfs                1.8G     0  1.8G   0% /dev/shm
tmpfs                1.8G  8.9M  1.8G   1% /run
tmpfs                1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/sda1            497M  195M  303M  40% /boot
tmpfs                369M     0  369M   0% /run/user/0
/dev/sdb1             20G   45M   19G   1% /sdb

fsck修复危险性较大,建议先备份对应的分区(dd命令备份分区)然后再处理,有导致分区数据全部或者部分丢失的风险,如果超级块彻底损坏无法恢复,请联系我们，提供专业ORACLE数据库恢复技术支持
Phone:17813235971    Q Q:107644445QQ咨询惜分飞    E-Mail:dba@xifenfei.com

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linux 7(redhat,oracle linux,centos)中使用udev

发表于 2016 年 8 月 7 日 由 惜分飞

慢慢的linux 7的使用人越来越多了,但是linux 7相对于5和6的版本,变动确实比较大,本文主要描写在linux 7中如何实现udev,实现设备持久化,权限和所属组的修改
linux版本

Oracle Linux Server release 7.1
[root@www.xifenfei.com ~]# uname -a
Linux www.xifenfei.com 3.10.0-229.el7.x86_64 #1 SMP Fri Mar 6 04:05:24 PST 2015 x86_64 x86_64 x86_64 GNU/Linux

VMware Workstation中显示uuid需要在vmx文件中增加

disk.enableUUID = "TRUE"

查看磁盘分区

[root@www.xifenfei.com ~]# fdisk -l

Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0xf60fe217

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     2099199     1048576   83  Linux

Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000bce7c

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048     4204543     2101248   8e  Linux LVM
/dev/sda2   *     4204544    79702015    37748736   83  Linux

Disk /dev/sdc: 32.2 GB, 32212254720 bytes, 62914560 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/ol-swap: 2147 MB, 2147483648 bytes, 4194304 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

查看磁盘uuid

[root@www.xifenfei.com ~]# /usr/lib/udev/scsi_id -g -u /dev/sdb1
36000c29e91831cedbe69afe6cc08daf7
[root@www.xifenfei.com ~]# /usr/lib/udev/scsi_id -g -u /dev/sdc
36000c292495e9d9de6f21640cc7b53b9

udev绑定

[root@www.xifenfei.com ~]# more /etc/udev/rules.d/99-my-asmdevices.rules 
KERNEL=="sd*[!0-9]", ENV{DEVTYPE}=="disk", SUBSYSTEM=="block", PROGRAM=="/usr/lib/udev/scsi_id -g -u -d $devnode",
 RESULT=="36000c292495e9d9de6f21640cc7b53b9", RUN+="/bin/sh -c 'mknod /dev/xifenfei-sdc b $major $minor; 
chown oracle:dba /dev/xifenfei-sdc; chmod 0660 /dev/xifenfei-sdc'"

KERNEL=="sd?1", SUBSYSTEM=="block", PROGRAM=="/lib/udev/scsi_id -g -u -d /dev/$parent", 
RESULT=="36000c29e91831cedbe69afe6cc08daf7", SYMLINK+="xifenfei-sdb1", OWNER="oracle", GROUP="dba", MODE="0660"

绑定结果

[root@www.xifenfei.com ~]# ls -l /dev/xifenfei-*
lrwxrwxrwx. 1 root   root     4 Aug  7 22:49 /dev/xifenfei-sdb1 -> sdb1
brw-rw----. 1 oracle dba  8, 32 Aug  7 22:36 /dev/xifenfei-sdc
[root@www.xifenfei.com ~]# ls -l /dev/sdb1
brw-rw----. 1 oracle dba 8, 17 Aug  7 22:49 /dev/sdb1

udev只修改磁盘权限

[root@www.xifenfei.com ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Command (m for help): n
Partition type:
   p   primary (1 primary, 0 extended, 3 free)
   e   extended
Select (default p): p
Partition number (2-4, default 2): 
First sector (2099200-41943039, default 2099200): 
Using default value 2099200
Last sector, +sectors or +size{K,M,G} (2099200-41943039, default 41943039): +1G
Partition 2 of type Linux and of size 1 GiB is set

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
[root@www.xifenfei.com ~]# more /etc/udev/rules.d/99-my-asmdevices.rules 
KERNEL=="sd?2", SUBSYSTEM=="block", PROGRAM=="/lib/udev/scsi_id -g -u -d /dev/$parent",
 RESULT=="36000c29e91831cedbe69afe6cc08daf7",  OWNER="oracle", GROUP="dba", MODE="0660"
[root@www.xifenfei.com ~]# /sbin/udevadm trigger --type=devices --action=change
[root@www.xifenfei.com ~]# ls -l /dev/sdb2
brw-rw----. 1 oracle dba 8, 18 Aug  7 23:14 /dev/sdb2

这里可以发现在linux 7中使用了两种方法绑定udev,一种是真实生成udev设备,另外一种是通过软连接实现.感谢lunar(Lunar的oracle实验室)在linux 7学习中的帮助

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使用losetup实现linux普通文件做asm disk

发表于 2016 年 6 月 18 日 由 惜分飞

上一篇文章《使用_asm_allow_only_raw_disks实现普通文件做asm disk》中已经介绍使用_asm_allow_only_raw_disks参数使得oracle asm可以使用文件作为asm disk,这篇文章介绍在linux中还可以通过losetup来实现文件系统模拟磁盘实现使用文件系统做asm disk的效果
通过dd构造文件

[oracle@xifenfei ~]$ mkdir /u01/oracle/oradata/asmdisk
[oracle@xifenfei ~]$ dd if=/dev/zero of=/u01/oracle/oradata/asmdisk/xifenfei01.dd bs=10240k count=100
100+0 records in
100+0 records out
1048576000 bytes (1.0 GB) copied, 21.9158 seconds, 47.8 MB/s
[oracle@xifenfei ~]$ dd if=/dev/zero of=/u01/oracle/oradata/asmdisk/xifenfei02.dd bs=10240k count=100
100+0 records in
100+0 records out
1048576000 bytes (1.0 GB) copied, 22.392 seconds, 46.8 MB/s
[oracle@xifenfei ~]$ ls -lh /u01/oracle/oradata/asmdisk/
total 3.0G
-rw-r--r-- 1 oracle oinstall 1000M Feb 27 22:58 xifenfei01.dd
-rw-r--r-- 1 oracle oinstall 1000M Feb 27 23:00 xifenfei02.dd

使用losetup模拟磁盘

[root@xifenfei asmdisk]# ls -l /dev/lo
log    loop0  loop1  loop2  loop3  loop4  loop5  loop6  loop7  
[root@xifenfei asmdisk]# losetup /dev/loop1 xifenfei01.dd 
[root@xifenfei asmdisk]# losetup /dev/loop2 xifenfei02.dd

使用raw实现磁盘转换为裸设备

[root@xifenfei asmdisk]# raw  /dev/raw/raw10 /dev/loop1 
/dev/raw/raw10: bound to major 7, minor 1
[root@xifenfei asmdisk]# raw  /dev/raw/raw11 /dev/loop2 
/dev/raw/raw11: bound to major 7, minor 2
[root@xifenfei asmdisk]# ls -l /dev/raw/raw1[0-1]
crw------- 1 root root 162, 10 Feb 27 23:16 /dev/raw/raw10
crw------- 1 root root 162, 11 Feb 27 23:16 /dev/raw/raw11
[root@xifenfei asmdisk]# chown oracle.dba /dev/raw/raw1[0-1]
[root@xifenfei asmdisk]# ls -l /dev/raw/raw1[0-1]
crw------- 1 oracle dba 162, 10 Feb 27 23:16 /dev/raw/raw10
crw------- 1 oracle dba 162, 11 Feb 27 23:16 /dev/raw/raw11

创建磁盘组

[oracle@xifenfei ~]$ export ORACLE_SID=+ASM
[oracle@xifenfei ~]$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.4.0 - Production on Thu Feb 27 23:19:28 2014

Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options


SQL>  create diskgroup xff external redundancy disk '/dev/raw/raw10','/dev/raw/raw11';

Diskgroup created.

SQL> select group_number,name from v$asm_diskgroup;

GROUP_NUMBER NAME
------------ ------------------------------------------------------------
           1 DATA
           2 XFF

SQL> select path,TOTAL_MB from v$asm_disk where group_number=2;

PATH                   TOTAL_MB
-------------------- ----------
/dev/raw/raw11             1000
/dev/raw/raw10             1000

通过kfed验证asm disk是数据文件

[oracle@xifenfei tmp]$ kfed read /dev/raw/raw10|grep XFF
kfdhdb.dskname:                XFF_0000 ; 0x028: length=8
kfdhdb.grpname:                     XFF ; 0x048: length=3
kfdhdb.fgname:                 XFF_0000 ; 0x068: length=8
[oracle@xifenfei tmp]$ kfed read /dev/raw/raw11|grep XFF
kfdhdb.dskname:                XFF_0001 ; 0x028: length=8
kfdhdb.grpname:                     XFF ; 0x048: length=3
kfdhdb.fgname:                 XFF_0001 ; 0x068: length=8
[oracle@xifenfei tmp]$ kfed read /u01/oracle/oradata/asmdisk/xifenfei01.dd |grep XFF
kfdhdb.dskname:                XFF_0000 ; 0x028: length=8
kfdhdb.grpname:                     XFF ; 0x048: length=3
kfdhdb.fgname:                 XFF_0000 ; 0x068: length=8
[oracle@xifenfei tmp]$ kfed read /u01/oracle/oradata/asmdisk/xifenfei02.dd |grep XFF
kfdhdb.dskname:                XFF_0001 ; 0x028: length=8
kfdhdb.grpname:                     XFF ; 0x048: length=3
kfdhdb.fgname:                 XFF_0001 ; 0x068: length=8

通过kfed命令,确定asm本质是用了dd出来的数据文件做asm disk.

发表在 Linux, Oracle ASM | 标签为 | 评论关闭