作者daimoway·2012-11-28 15:37

软件开发工程师·dearwears

AIX基础笔记（8） File systems administration

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*JFS2 structural components

- Superblock: The superblock maintains
informaition about the entire file system.

- i-nodes: Each file and directory has an
i-node that contains access information such as file type, access permissions,
owner's ID, and number of links to that file.

- Data blocks: Contains file data; Each file
system has a user settable fixed block size attribute -- 512, 1024, 2048 or
4096 bytes.

- Allocation maps: Record the location and
allocation of all i-nodes and the allocation state of each data block.

- Allocation groups: Responsible for dividing
the file system space into chunks so related data blocks and i-nodes can be
clustered together to achieve good locality.

*Listing i-node and block size information

(1) To
view i-node information:

# ls -li

total 0

73863 -rw-rw-r--    1 root    
system            0 Mar 26 16:06
newfile

# istat
newfile

Inode 73863 on device
10/7      File

Protection:
rw-rw-r--

Owner: 0(root)          Group: 0(system)

Link count:   1        
Length 0 bytes

Last updated:   Mon Mar 26 16:16:05 GMT+08:00 2012

Last modified:  Mon Mar 26 16:06:59 GMT+08:00 2012

Last accessed:  Mon Mar 26 16:06:59 GMT+08:00 2012

(2) To
view file system block size informaiton:

# lsfs -cq
/

#MountPoint:Device:Vfs:Nodename:Type:Size:Options:AutoMount:Acct

/:/dev/hd4:jfs2::bootfs:155189248:rw:yes:no

(lv size 155189248:fs size 155189248:block size 4096:sparse
files yes:inline log no:inline log size 0:EAformat v1:Quota no:DMAPI no:VIX
yes:EFS no:ISNAPSHOT no:MAXEXT 0)

*Creating a JFS2 file system

# crfs -v jfs2 -g datavg -a size=1G -m /pdmdata   (or)

# smitty crfs_j2

Add an Enhanced Journaled
File System

Type or select
values in entry fields.

Press Enter AFTER
making all desired changes.

[Entry Fields]

Volume group name                                   datavg

SIZE of file system

Unit Size                                  
Gigabytes              +

*         Number of units                            [1]                      #

*
MOUNT POINT                                        [/pdmdata]

Mount AUTOMATICALLY at system restart?              no                     +

PERMISSIONS                                        
read/write             +

Mount OPTIONS                                      []                      +

Block Size (bytes)                                  4096                   +

Logical Volume for Log                                                    
+

Inline Log size (MBytes)                           []                       #

Extended Attribute Format                                                 
+

ENABLE Quota Management?                            no                     +

Enable EFS?                                        
no                     +

Allow internal snapshots?                           no                     +

Mount GROUP                                        []

# lsfs
/pdmdata

Name            Nodename   Mount Pt               VFS   Size   
Options    Auto Accounting

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

# lsvg -l
datavg

datavg:

LV NAME             TYPE       LPs    
PPs     PVs  LV STATE     
MOUNT POINT

datelv01            jfs2       600    
600     1    closed/syncd  N/A

loglv00             jfs2log    1      
1       1    closed/syncd  N/A

fslv01              jfs2       1200   
1200    2    closed/syncd  /pdmdata

*Mounting a file system and the /etc/filesystems file

# grep -p
/pdmdata /etc/filesystems

/pdmdata:

dev             = /dev/fslv01

vfs             = jfs2

log             = /dev/loglv00

mount           = false

account         = false

# mount
/pdmdata

# mount |
egrep '(/pdmdata|node)'

node      
mounted        mounted over    vfs      
date        options

/dev/fslv01      /pdmdata         jfs2  
Mar 27 14:32 rw,log=/dev/loglv00

*JFS2 logging options

For JFS2
file systems, there are three logging options:

(1) Use
the global JFS log for the volume group.

(2)
Create a specific JFS log for each file system.

- 1 LP in size

- Format the log using the logform command.

# mklv -y my_jfs2_log -t jfs2log datavg 1

# logform /dev/my_jfs2_log

logform:
destroy /dev/my_jfs2_log (y) ? y

# crfs -v jfs2 -g datavg -a size=1G -m /data -a logname=my_jfs2_log

(3)
Create an inline log inside the file system: 0.4% of the file system space will
be reserved for this option.

# crfs -v jfs2 -g datavg -a size=1G -m /data -a
logname=INLINE  [(or) -a
logsize=<value in MB>]

*Creating a file system on a previously defined
logical volume

# crfs -v jfs2 -d lv_for_data -m /data2 -A yes   (or)

# smitty crfs_j2

Add an Enhanced Journaled
File System

Type or select
values in entry fields.

Press Enter AFTER
making all desired changes.

[Entry Fields]

*
LOGICAL VOLUME name                                 lv_for_data              +

* MOUNT POINT                                       
[/data2]