AIX 基础笔记3 System storage overview

*Components of AIX storage

-Physical storage

-Logical storage

-File systems

-Directories

-Files

Managed by Logical Volume Manager (LVM)

*Benefits of the LVM

-Solves noncontiguous space problems

-Data can span disks

-Sizes can be dynamically increased

-Data can be mirrored for availability

-New disks are easily added to the system

-Data can be relocated

-LVM (data) statistics can be collected

*Logical Volume Manager components

-Volume group (VG)

-Physical volume (PV)

-Physical partition (PP)

-Logical volume (LV)

-Logical partition (LP)

*Volume group descriptor area (VGDA)

There must be a quorum of VGDAs available to activate the volume group and make it available for use with the varyonvg command. A quorum of VGDA copies is needed to ensure the data integrity of management data that describes the logical and physical volumes in the volume group. A quorum is equal to 51% or more of the VGDAs avaiable.

*Uses of logical volumes

(1) A logical volume may contain one of the following:

      -Journaled ( JFS) or enhanced journaled file system (JFS2)

      -Journal log (/dev/hd8)

      -Paging space (/dev/hd6)

      -Boot logical volume (/dev/hd5)

      -Dump device

      -Nothing (raw logical volume)

(2) Examples of JFS/JFS2 logical volumes:

                /dev/hd1                    /home

                /dev/hd2                    /usr

                /dev/hd3                    /tmp

                /dev/hd4                    /

                /dev/hd9var               /var

                /dev/hd10opt            /opt

                /dev/hd11admin       /admin

                /dev/lv00                    /myfilesystem

*What is a file system?

(1) A file system is :

  - Method of storing data

  - Hierarchy of directories

(2) Seven types supported :

  - Journaled File System (JFS)

  - Enhanced Journaled File System (JFS2)

  - CD-ROM File System (CDRFS)

  - DVD-ROM File System (UDFS)

  - Network File System (NFS)

  - Common Internet Filesystem (CIFS)

  - Proc File System (PROCFS)

(3) Different file systems are connected together through directories to form the view of files that users see.

*Why have multiple file systems?

- Can strategically place it on disk for improved performance

- Some tasks are performed more efficiently on a file system than on each directory within the file system, for example , back up , move, secure an entire file system.

- Can limit disk usage of users by file system through quotas

- Maintain integrity of the entire file system structure, for example, if one file system is corrupted, the others are not affected

- Special security situations

- Organize data and programs into groups for ease of file management and better performance

*Standard file systems in AIX

                                                                                                                /(root)=/dev/hd4

                                                                                                                 |

----------------------------------------------------------------------------------------------------------------------------------------------------------

|                |              |                |              |                |               |                 |                 |                   |                  |                     |

home       sbin         opt            lpp           proc          usr           dev            tftpboot    var               mnt             etc                  tmp

hd1                           hd10opt                                     hd2                                                hd9var                                                    hd3

*/etc/filesystems

# cat /etc/filesystems

* @(#)filesystems @(#)29        1.23  src/bos/etc/filesystems/filesystems, cmdfs, bos61B, b2007_38A8 8/16/07 17:18:35

* IBM_PROLOG_BEGIN_TAG

* This is an automatically generated prolog.

*

* bos61B src/bos/etc/filesystems/filesystems 1.23

* Licensed Materials - Property of IBM

* COPYRIGHT International Business Machines Corp. 1985,1993

* All Rights Reserved

* US Government Users Restricted Rights - Use, duplication or

* disclosure restricted by GSA ADP Schedule Contract with IBM Corp.

* IBM_PROLOG_END_TAG

* COMPONENT_NAME: CMDFS

* FUNCTIONS: none

* ORIGINS: 27

* (C) COPYRIGHT International Business Machines Corp. 1985, 1993

* This version of /etc/filesystems assumes that only the root file system

* is created and ready.  As new file systems are added, change the check,

* mount, free, log, vol and vfs entries for the appropriate stanza.

/:

        dev             = /dev/hd4

        vfs             = jfs2

        log             = /dev/hd8

        mount           = automatic

        check           = false

        type            = bootfs

        vol             = root

        free            = true

/home:

        dev             = /dev/hd1

        mount           = true

        check           = true

        vol             = /home

        free            = false

/usr:

        dev             = /dev/hd2

        vol             = /usr

/var:

        dev             = /dev/hd9var

        vol             = /var

/tmp:

        dev             = /dev/hd3

        vol             = /tmp

/admin:

        dev       = /dev/hd11admin

        vol       = "/admin"

        mount     = true

        check     = false

        free      = false

        vfs       = jfs2

        log       = /dev/hd8

/proc:

        dev       = /proc

        vol       = "/proc"

        vfs       = procfs

/opt:

        dev             = /dev/hd10opt

        vol             = /opt

/var/adm/ras/platform:

        dev             = /dev/fwdump

        mount           = false

        account         = false

/var/adm/ras/livedump:

        dev             = /dev/livedump

/ptc:

        dev             = /dev/fslv00

        options         = rw

/pdmdata:

        dev             = /dev/fslv01

        log             = /dev/loglv00

/oracle:

        dev             = /dev/fslv02

/ftp:

        dev             = /dev/fslv03

/ptc/Windchill/temp/print:

        dev             = print

        vfs             = cifs

        nodename        = x3550-PC/x3550

        options         = rw,uid=12,gid=0,fmode=777

*Mount

# mount -rv cdrfs /dev/cd0 /mnt

# unmount /mnt

# mount /dev/fslv00 /home/patsie

                ---------------  ------------------

         what to mount      where to mount

# unmount /home/patsie

*Listing file systems

# lsfs

Name            Nodename   Mount Pt               VFS   Size    Options    Auto Accounting

/dev/hd4        --         /                      jfs2  155189248 --         yes  no

/dev/hd1        --         /home                  jfs2  82837504 --         yes  no

/dev/hd2        --         /usr                   jfs2  20971520 --         yes  no

/dev/hd9var     --         /var                   jfs2  20971520 --         yes  no

/dev/hd3        --         /tmp                   jfs2  20971520 --         yes  no

/dev/hd11admin  --         /admin                 jfs2  1048576 --         yes  no

/proc           --         /proc                  procfs --      --         yes  no

/dev/hd10opt    --         /opt                   jfs2  20971520 --         yes  no

/dev/fwdump     --         /var/adm/ras/platform  jfs2  2097152 --         no   no

/dev/livedump   --         /var/adm/ras/livedump  jfs2  1048576 --         yes  no

/dev/fslv00     --         /ptc                   jfs2  209715200 rw         yes  no

/dev/fslv01     --         /pdmdata               jfs2  629145600 --         no   no

/dev/fslv02     --         /oracle                jfs2  125829120 rw         yes  no

/dev/fslv03     --         /ftp                   jfs2  20971520 rw         yes  no

print           x3550-PC/x3550 /ptc/Windchill/temp/print cifs  --      rw,uid=12,gid=0,fmode=777 yes  no

*Listing logical volume information

# lsvg

rootvg

datavg

# lsvg -l rootvg

rootvg:

LV NAME             TYPE       LPs     PPs     PVs  LV STATE      MOUNT POINT

hd5                 boot       1       2       2    closed/syncd  N/A

hd6                 paging     44      88      2    open/syncd    N/A

hd8                 jfs2log    1       2       2    open/syncd    N/A

hd4                 jfs2       148     296     2    open/syncd    /

hd2                 jfs2       20      40      2    open/syncd    /usr

hd9var              jfs2       20      40      2    open/syncd    /var

hd3                 jfs2       20      40      2    open/syncd    /tmp

hd1                 jfs2       79      158     2    open/syncd    /home

hd10opt             jfs2       20      40      2    open/syncd    /opt

hd11admin           jfs2       1       2       2    open/syncd    /admin

fwdump              jfs2       2       4       2    open/syncd    /var/adm/ras/platform

lg_dumplv           sysdump    4       4       1    open/syncd    N/A

livedump            jfs2       1       2       2    open/syncd    /var/adm/ras/livedump

fslv00              jfs2       200     200     1    open/syncd    /ptc