Post will cover the following topics :
- EXT2/EXT3 file system attributes
- ACL in RHEL and SOLARIS
- SUDO
- SU
- UFS file system in SOLARIS10
EXT2/EXT3 file system attributes
Filesystem attributes can help you control what anyone can do with different files. The key commands in this area are
lsattr and chattr. The use I'm most familiar with protects a file from deletion, even by the root user. For example, you could protect /etc/inittab from tinkering by other administrators with the following command:# chattr +i /etc/inittabThen when I try to delete the file, I get the following result:
# rm /etc/inittab
rm: remove write-protected regular file '/etc/inittab'? y
rm: cannot remove '/etc/inittab': Operation not permitted
This adds the immutable attribute to /etc/inittab:
# lsattr /etc/inittab
----i-------- /etc/inittab
| Attribute | Description |
| append only (a) | Prevents deletion, but allows appending to a file-for example, if you've run chatter +a tester, cat /etc/fstab >> tester would add the contents of /etc/fstab to the end of the tester file. |
| no dump (d) | Does not allow backups of the configured file with the dump command. |
| immutable (i) | Prevents deletion or any other kind of change to a file. |
ACL in RHEL and SOLARIS
ACL (Access Control List) is in a context of file systems a mechanism to control access to files and directories. This mechanism appears in SOL10 as well as in RHEL5 but there is a slight difference in implementation. In SOL10 it is available by default, sys admin doesn't have to do any additional tasks in order to enable this feature but in RHEL5, file system with ACL capability must be mounted with that feature so it is not available by default after clean oes installation.
RHEL5
In RHEL5 a ext3/4 file system allows you to use this feature when you mount it with acl option e.g. :
# mount -t ext4 -o acl,defaults /dev/sda3 /mntIf you're just testing a system for ACL, you can remount an existing partition appropriately :
# mount -o remount -o acl /dev/sda3 /home1. Read ACL :
# getfacl /home/donna/abc# file: home/donna/abc # owner: donna # group: donna user::rw- group::rw- other::r--
2. Set ACL :
# setfacl -m user:michael:r-x /home/donna
# setfacl -m mask:r-x /home/donna
SOL10
Commands are the same for RHEl and SOL :
-
getfacl-
setfaclWe have here trivial and non-trivial ACL. Trivial is the standard permission set and can be read with
ls command but non-trivial can only be read with getfacl cmd and when is also described + sign when you perform ls -la. 1. Read trivial ACL for all files and dirs:
$ ls -ladrwxr-xr-x 4 jakubn other 512 cz 20 14:52 . drwxr-xr-x 5 root root 512 cz 20 14:45 .. -rw-r--r-- 1 jakubn other 20 cz 9 22:11 .exrc -rwxr--r-- 1 jakubn other 648 cz 18 21:59 .kshrc -rw-r--r-- 1 jakubn other 51 cz 9 22:15 .profile -rw------- 1 jakubn other 5654 cz 20 16:20 .sh_history -------r-- 1 jakubn other 0 cz 20 14:52 file1.txt drwxr-xr-x+ 2 jakubn other 512 cz 18 21:32 lilo drwx------ 2 root root 512 lut 10 01:22 lost+found
2. Read trivial ACL for a particular file/dir:
jakubn@solaris10 /export/home/jakubn $getfacl -a file1.txt# file: file1.txt # owner: jakubn # group: other user::--- group::--- #effective:--- mask:--- other:r--
3. Read non-trivial ACL :
$ ls -la lilo
drwxr-xr-x+ 2 jakubn other 512 cz 18 21:32 liloPlease observe additional
+ sign in output from ls cmd, this means that this file posses non-trivial ACL.jakubn@solaris10 /export/home/jakubn $getfacl lilo# file: lilo # owner: jakubn # group: other user::rwx user:wawer:rwx #effective:r-x group::r-x #effective:r-x mask:r-x other:r-x
4. Set non-trivial ACL for user "pioko"
$ setfacl -m user:pioko:rw- file2.txt5. Substitute ACL for file2.txt
setfacl -s u::rwx,g::rw-,o::r--,m::rw-,u:usera:rwx file2.txt6. Change effective mask for all users in ACL :
$ getfacl file2# file: file2 # owner: userc # group: sysadmin user::rw- user:usera:rwx #effective:r-- user:userb:rwx #effective:r-- group::r-- #effective:r-- mask:r-- other:r--
$setfacl -m m:rwx file2
$getfacl file2# file: file2 # owner: userc # group: sysadmin user::rw- user:usera:rwx #effective:rwx user:userb:rwx #effective:rwx group::r-- #effective:rwx mask:rwx other:r--
7. Recalculating ACL mask :
$ getfacl file1# file: file1 # owner: userc # group: sysadmin user::rwx user:usera:rwx #effective:rw- group::rw- #effective:rw- mask:rw- other:r--
$ setfacl -r -m u:usera:7 file1
$ getfacl file1# file: file1 # owner: userc # group: sysadmin user::rwx user:usera:rwx #effective:rwx group::rw- #effective:rw- mask:rwx other:r--The file owner and other permissions are not considered when recalculating the ACL mask.
8. Using
chmod cmd on a file that already has ACL to recalculate mask :$ getfacl testfile# file: testfile # owner: user1 # group: staff user::rw- user:user2:rw- #effective:r-- group::r-- #effective:r-- mask:r-- other:r--
$ chmod 664 testfile
$ getfacl testfile# file: testfile # owner: user1 # group: staff user::rw- user:user2:rw- #effective:rw- group::rw- #effective:rw- mask:rw-
SUDO
SUDO (superuser do) is a mechanism to give permissions for certain users, groups to allow them access to files and dirs.
In Solaris we use ACL and RBAC mechanism instead of sudo but on Linux it is widely used.
Whole configuration is in /etc/sudoers file and can be done by using :
-
# visudo-
# vi /etc/sudoersIt is highly recommended to use visudo cmd instead of standard vi.
SYNTAX
user1 host=(user2) program user1 can execute on host computer, application named program with rights of user2.Usage Scenarios :
root ALL=(ALL) ALL Allows root user to execute by using sudo all programs on the machine
user2 ALL = ALL, !/usr/bin/passwd root Allows user2 to execute all programs on the machine by using sudo without changing password for root user.
user3 ALL = NOPASSWD: /usr/bin/crontab, PASSWD: /usr/bin/procmail, /usr/bin/lpr Allows user3 to to run
crontab without password and procmail and lpr with typing password.%users ALL = NOPASSWD: /usr/bin/passwd, !/usr/bin/passwd root Allows members of users group to use
passwd cmd by using sudo utility without password and not using passwd cmd to change password for the root user.user7 localhost=(root) /sbin/ifconfigAllows user7 to run
ifconfig cmd with root permissions.sudo -lDisplays how sudo is configured for user who executes this command.
SU
SU (switch user OR superuser) allows you to change user identity on unix system whether on different user or rootuser.
SYNTAX
su [OPTION]... [-] [USER [ARG]...]Usage scenarios
su -Switch to root user with environment vars.
su -c 'fdisk -l'Run command fdisk -l with root user rghts.
su - jakubnSwitch to user jakubn with env vars. When you are logged in as root and want to change identity to any other user with this command, you don't have to type this user's password otherwise you have to.
suSwitch to root account without env vars.
idDisplays current identity of user you are using now.
who am iDisplays first identity user had when first logged in.
UFS file system in SOLARIS10
- Adding new disk
- Displaying devices
- Create new file system
- Check file system
- Mount fs
- Unmounts fs
- VOLD Volume Management Daemon
Adding new disk into SOLARIS10
There are 3 ways you can add new disk (any hardware) in SOLARIS10 :
1. reconfiguration boot
2. manual reconfiguration boot from ok> prompt
3. devfsadm command
reconfiguration boot
-
# touch /reconfigure
- # init 5- install peripheral device
- turn on the power
- verify peripheral device have been added with prtconf cmd.
manual reconfiguration boot from ok> prompt
-
ok> boot -rdevfsadm command
- devfsadm -c disk
SYNTAX :
----------
devfsadm -c class ---> configure devices of class
devfsadm -i driver name ---> configure only devices for a named driver
Usage scenario :
------------------
devfsadm -c disk
devfsadm -c tape
devfsadm -c audio
devfsadm -i dad
devfsadm -i sd
devfsadm -v ---> displays verbose output of changes
devfsadm -C ---> cleans up unreferenced symbolic links for devices
Displaying devices in SOLARIS10
There are 3 ways to display actually available devices in SOLARIS10 :
- /etc/path_to_inst
- prtconf command
- format command
/etc/path_to_inst
For each device system records its physical name and instance name in this file. There names are used by the kernel to identify every possible device. This file is used at boot time.
It is maintained by the kernel and is not advisable to edit is manually by system admin.
# cat /etc/path_to_inst # # Caution! This file contains critical kernel state # "/iscsi" 0 "iscsi" "/pseudo" 0 "pseudo" "/options" 0 "options" "/xsvc" 0 "xsvc" "/objmgr" 0 "objmgr" "/scsi_vhci" 0 "scsi_vhci" "/isa" 0 "isa" "/isa/i8042@1,60" 0 "i8042" "/isa/i8042@1,60/keyboard@0" 0 "kb8042" "/isa/i8042@1,60/mouse@1" 0 "mouse8042" "/isa/lp@1,378" 0 "ecpp" "/ramdisk" 0 "ramdisk" "/cpus" 0 "cpunex" "/cpus/cpu@0" 0 "cpudrv" "/pci@0,0" 0 "pci" "/pci@0,0/display@2" 0 "vgatext" "/pci@0,0/pci106b,3f@6" 0 "ohci" "/pci@0,0/pci106b,3f@6/input@1" 0 "hid" "/pci@0,0/pci8086,1e@3" 0 "e1000g" "/pci@0,0/pci8086,2829@d" 0 "ahci" "/pci@0,0/pci8086,2829@d/disk@0,0" 0 "sd" "/pci@0,0/pci8086,2829@d/cdrom@1,0" 1 "sd" "/pci@0,0/pci8086,1e@8" 1 "e1000g" "/agpgart" 0 "agpgart"
prtconf command
Displays current memory installed and peripherals.
# prtconf | grep -v not
System Configuration: Sun Microsystems i86pc
Memory size: 1024 Megabytes
System Peripherals (Software Nodes):
i86pc
scsi_vhci, instance #0
isa, instance #0
i8042, instance #0
keyboard, instance #0
mouse, instance #0
lp, instance #0
pci, instance #0
display, instance #0
pci8086,1e, instance #0
pci106b,3f, instance #0
input, instance #0
pci8086,1e, instance #1
pci8086,2829, instance #0
disk, instance #0
cdrom, instance #1
iscsi, instance #0
pseudo, instance #0
agpgart, instance #0
options, instance #0
objmgr, instance #0
xsvc, instance #0
cpus, instance #0
format command
Displays current disk installed and allows to initialize disk with VTOC table.
# format
Searching for disks...done
AVAILABLE DISK SELECTIONS:
0. c0t0d0
/pci@0,0/pci8086,2829@d/disk@0,0
Specify disk (enter its number): 0
selecting c0t0d0
[disk formatted]
Warning: Current Disk has mounted partitions.
/dev/dsk/c0t0d0s0 is currently mounted on /. Please see umount(1M).
/dev/dsk/c0t0d0s1 is currently used by swap. Please see swap(1M).
/dev/dsk/c0t0d0s7 is currently mounted on /export/home. Please see umount(1M).
FORMAT MENU:
disk - select a disk
type - select (define) a disk type
partition - select (define) a partition table
current - describe the current disk
format - format and analyze the disk
fdisk - run the fdisk program
repair - repair a defective sector
label - write label to the disk
analyze - surface analysis
defect - defect list management
backup - search for backup labels
verify - read and display labels
save - save new disk/partition definitions
inquiry - show vendor, product and revision
volname - set 8-character volume name
! - execute , then return
quit
format>
Run fdisk command within format utility to label VTOC table.
fdiskCreate new UFS file system
1. Write defualt VTOC to label the disk.
format> fdisk No fdisk table exists. The default partition for the disk is: a 100% "SOLARIS System" partition Type "y" to accept the default partition, otherwise type "n" to edit the partition table. y
2. Divide disk into slices
# format
Searching for disks...done
AVAILABLE DISK SELECTIONS:
0. c0t0d0
/pci@0,0/pci8086,2829@d/disk@0,0
1. c0t2d0
/pci@0,0/pci8086,2829@d/disk@2,0
Specify disk (enter its number): 1
selecting c0t2d0
[disk formatted]
FORMAT MENU:
disk - select a disk
type - select (define) a disk type
partition - select (define) a partition table
current - describe the current disk
format - format and analyze the disk
fdisk - run the fdisk program
repair - repair a defective sector
label - write label to the disk
analyze - surface analysis
defect - defect list management
backup - search for backup labels
verify - read and display labels
save - save new disk/partition definitions
inquiry - show vendor, product and revision
volname - set 8-character volume name
! - execute , then return
quit
format> partition
PARTITION MENU:
0 - change `0' partition
1 - change `1' partition
2 - change `2' partition
3 - change `3' partition
4 - change `4' partition
5 - change `5' partition
6 - change `6' partition
7 - change `7' partition
select - select a predefined table
modify - modify a predefined partition table
name - name the current table
print - display the current table
label - write partition map and label to the disk
! - execute , then return
quit
partition> modify
Select partitioning base:
0. Current partition table (original)
1. All Free Hog
Choose base (enter number) [0]? 0
Part Tag Flag Cylinders Size Blocks
0 unassigned wm 0 0 (0/0/0) 0
1 unassigned wm 0 0 (0/0/0) 0
2 backup wu 0 - 1019 1.99GB (1020/0/0) 4177920
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 unassigned wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0
8 boot wu 0 - 0 2.00MB (1/0/0) 4096
9 unassigned wm 0 0 (0/0/0) 0
Do you wish to continue creating a new partition
table based on above table[yes]?
Free Hog partition[6]? ^C
partition>
partition> modify
Select partitioning base:
0. Current partition table (original)
1. All Free Hog
Choose base (enter number) [0]? 1
Part Tag Flag Cylinders Size Blocks
0 root wm 0 0 (0/0/0) 0
1 swap wu 0 0 (0/0/0) 0
2 backup wu 0 - 1019 1.99GB (1020/0/0) 4177920
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 usr wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0
8 boot wu 0 - 0 2.00MB (1/0/0) 4096
9 alternates wm 0 0 (0/0/0) 0
Do you wish to continue creating a new partition
table based on above table[yes]?
Free Hog partition[6]?
Enter size of partition '0' [0b, 0c, 0.00mb, 0.00gb]: ?
Expecting up to 4173824 blocks, 1019 cylinders, 2038.00 megabytes, or 1.99 gigabytes
Enter size of partition '0' [0b, 0c, 0.00mb, 0.00gb]: 1.99gb
Warning: no space available for '1' from Free Hog partition
Warning: no space available for '3' from Free Hog partition
Warning: no space available for '4' from Free Hog partition
Warning: no space available for '5' from Free Hog partition
Warning: no space available for '7' from Free Hog partition
Part Tag Flag Cylinders Size Blocks
0 root wm 1 - 1019 1.99GB (1019/0/0) 4173824
1 swap wu 0 0 (0/0/0) 0
2 backup wu 0 - 1019 1.99GB (1020/0/0) 4177920
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 usr wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0
8 boot wu 0 - 0 2.00MB (1/0/0) 4096
9 alternates wm 0 0 (0/0/0) 0
Okay to make this the current partition table[yes]?
Enter table name (remember quotes): var file system
Ready to label disk, continue?
Ready to label disk, continue? yes
partition> ?
Expecting one of the following: (abbreviations ok):
0 - change `0' partition
1 - change `1' partition
2 - change `2' partition
3 - change `3' partition
4 - change `4' partition
5 - change `5' partition
6 - change `6' partition
7 - change `7' partition
select - select a predefined table
modify - modify a predefined partition table
name - name the current table
print - display the current table
label - write partition map and label to the disk
! - execute , then return
quit
partition> print
Current partition table (var):
Total disk cylinders available: 1020 + 2 (reserved cylinders)
Part Tag Flag Cylinders Size Blocks
0 unassigned wm 1 - 1019 1.99GB (1019/0/0) 4173824
1 unassigned wm 0 0 (0/0/0) 0
2 backup wu 0 - 1019 1.99GB (1020/0/0) 4177920
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 unassigned wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0
8 boot wu 0 - 0 2.00MB (1/0/0) 4096
9 unassigned wm 0 0 (0/0/0) 0
partition> 0
Part Tag Flag Cylinders Size Blocks
0 unassigned wm 1 - 1019 1.99GB (1019/0/0) 4173824
Enter partition id tag[unassigned]: ?
Expecting one of the following: (abbreviations ok):
unassigned boot root swap
usr backup stand var
home alternates reserved
Enter partition id tag[unassigned]: var
Enter partition permission flags[wm]: wm
Enter new starting cyl[1]: ?
Expecting an integer from 0 to 1019
Enter new starting cyl[1]:
Enter partition size[4173824b, 1019c, 1019e, 2038.00mb, 1.99gb]: 1.99gb
partition> print
Current partition table (unnamed):
Total disk cylinders available: 1020 + 2 (reserved cylinders)
Part Tag Flag Cylinders Size Blocks
0 var wm 1 - 1019 1.99GB (1019/0/0) 4173824
1 unassigned wm 0 0 (0/0/0) 0
2 backup wu 0 - 1019 1.99GB (1020/0/0) 4177920
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 unassigned wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0
8 boot wu 0 - 0 2.00MB (1/0/0) 4096
9 unassigned wm 0 0 (0/0/0) 0
partition>label
Ready to label disk, continue? yes
partition> quit
FORMAT MENU:
disk - select a disk
type - select (define) a disk type
partition - select (define) a partition table
current - describe the current disk
format - format and analyze the disk
fdisk - run the fdisk program
repair - repair a defective sector
label - write label to the disk
analyze - surface analysis
defect - defect list management
backup - search for backup labels
verify - read and display labels
save - save new disk/partition definitions
inquiry - show vendor, product and revision
volname - set 8-character volume name
! - execute , then return
quit
format> quit
3. Create file system on device
# newfs /dev/rdsk/c0t2d0s0
newfs: construct a new file system /dev/rdsk/c0t2d0s0: (y/n)? y
/dev/rdsk/c0t2d0s0: 4173824 sectors in 1019 cylinders of 128 tracks, 32 sectors
2038,0MB in 45 cyl groups (23 c/g, 46,00MB/g, 11264 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
32, 94272, 188512, 282752, 376992, 471232, 565472, 659712, 753952, 848192,
3298432, 3392672, 3486912, 3581152, 3675392, 3769632, 3863872, 3958112,
4052352, 4146592
The first line describes basic disk geometry, the second ufs fs created on the slice. The third and remaining lines is the beginning sector location of the backup superblock.The newfs cmd reserves between 1-10% of disk space for maintenance. It is called minfree.
# fstyp -v /dev/rdsk/c0t2d0s0 | f^[^[[3~ f^[^[[3~: not found # # Broken Pipe Unknown_fstyp (no matches) # fstyp -v /dev/rdsk/c0t2d0s0 | head ufs magic 11954 format dynamic time Wed Jun 29 15:35:52 2011 sblkno 16 cblkno 24 iblkno 32 dblkno 1440 sbsize 2048 cgsize 8192 cgoffset 16 cgmask 0xffffff80 ncg 45 size 2086912 blocks 2022815 bsize 8192 shift 13 mask 0xffffe000 fsize 1024 shift 10 mask 0xfffffc00 frag 8 shift 3 fsbtodb 1 minfree 3% maxbpg 2048 optim time maxcontig 128 rotdelay 0ms rps 546 # Broken Pipe Unknown_fstyp (no matches)
This minfree value can be changed in 2 ways :
- recreating fs type
- redefining minfree on already created fs
recreating fs type
# newfs -m 1 /dev/rdsk/c0t2d0s0
newfs: construct a new file system /dev/rdsk/c0t2d0s0: (y/n)? y
/dev/rdsk/c0t2d0s0: 4173824 sectors in 1019 cylinders of 128 tracks, 32 sectors
2038,0MB in 45 cyl groups (23 c/g, 46,00MB/g, 11264 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
32, 94272, 188512, 282752, 376992, 471232, 565472, 659712, 753952, 848192,
3298432, 3392672, 3486912, 3581152, 3675392, 3769632, 3863872, 3958112,
4052352, 4146592
#
#
# fstyp -v /dev/rdsk/c0t2d0s0 | head
ufs
magic 11954 format dynamic time Wed Jun 29 16:03:38 2011
sblkno 16 cblkno 24 iblkno 32 dblkno 1440
sbsize 2048 cgsize 8192 cgoffset 16 cgmask 0xffffff80
ncg 45 size 2086912 blocks 2022815
bsize 8192 shift 13 mask 0xffffe000
fsize 1024 shift 10 mask 0xfffffc00
frag 8 shift 3 fsbtodb 1
minfree 1% maxbpg 2048 optim time
maxcontig 128 rotdelay 0ms rps 546
# Broken Pipe
Unknown_fstyp (no matches)
redefining minfree on already created fs
tunefs -m 1 /dev/rdsk/c0t2d0s0Check the file system
File system check program fsck check fs for data consistency and attempt to correct or repair any inconsistencies or damaged found. Every time systems boot up, it determines which fs should fsck check. The fsck comd checks and repairs any problems encountered in fs before they are mounted.
Any unreferenced inode with a non zero link count is linked to the file system's lost+found directory.
The fsck program has 2 modes of operation :
- noninteractive
- intercative
fsck noninteractive mode
- Operates this mode only during boot of SOL10.
- addresses only minor inconsistency problems
- if more serious problem is found and decision has to be made, fsck terminates and request root passwd to enter single-user mode
fsck noninteractive mode
- lists each problem it encounters followed by a suggetsion what to do
SYNTAX :
--------
fsck
Usage scenario
----------------
fsck /dev/rdsk/c0t0d0s0
To check single unmounted fs.
fsck /export/home
To check fs typing mount point (from /etc/vfstab)
# fsck -o f,p /dev/rdsk/c0t0d0s7 /dev/rdsk/c0t0d0s7: 77 files, 9621 used, 46089 free /dev/rdsk/c0t0d0s7: (4 frags, 57 blocks, 0.0% fragmentation)The f option of the fsck command forces a file system check, regardless of the state of the file system's superblock state flag.
The p option checks and fixes the file system noninteractively (preen). The program exits immediately if a problem requiring intervention is found.
# newfs -N /dev/rdsk/c0t2d0s0
/dev/rdsk/c0t2d0s0: 4173824 sectors in 1019 cylinders of 128 tracks, 32 sectors
2038,0MB in 45 cyl groups (23 c/g, 46,00MB/g, 11264 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
32, 94272, 188512, 282752, 376992, 471232, 565472, 659712, 753952, 848192,
3298432, 3392672, 3486912, 3581152, 3675392, 3769632, 3863872, 3958112,
4052352, 4146592
List alternative backup superblock locations in file system # fsck -o b=32 /dev/rdsk/c0t2d0s0 Alternate super block location: 32. ** /dev/rdsk/c0t2d0s0 ** Last Mounted on ** Phase 1 - Check Blocks and Sizes ** Phase 2 - Check Pathnames ** Phase 3a - Check Connectivity ** Phase 3b - Verify Shadows/ACLs ** Phase 4 - Check Reference Counts ** Phase 5 - Check Cylinder Groups UPDATE STANDARD SUPERBLOCK? y 2 files, 9 used, 2022806 free (14 frags, 252849 blocks, 0.0% fragmentation) ***** FILE SYSTEM WAS MODIFIED *****Recover superblock from backup superblock
Mount fs
File system have 3 different meanings in unix world :
- as a FS type
- as a slice/partition on the disk
- as mount point in directory tree
In order to mount fs there are 2 ways :
- to mount at boot by editing the /etc/vfstab file
- to mount manually by using the mount cmd
Structure of /etc/vfstab file.
# cat /etc/vfstab #device device mount FS fsck mount mount #to mount to fsck point type pass at boot options # fd - /dev/fd fd - no - /proc - /proc proc - no - /dev/dsk/c0t0d0s1 - - swap - no - /dev/dsk/c0t0d0s0 /dev/rdsk/c0t0d0s0 / ufs 1 no - /dev/dsk/c0t0d0s7 /dev/rdsk/c0t0d0s7 /export/home ufs 2 yes - /devices - /devices devfs - no - sharefs - /etc/dfs/sharetab sharefs - no - ctfs - /system/contract ctfs - no - objfs - /system/object objfs - no - swap - /tmp tmpfs - yes -
Column definitions :
------------------------------
- device to mount (device to be mounted)
- device to fsck (device character or raw to be check by fsck utility, pseudo fs have - in this field)
- mount point (the name of the dir that serves as attach point in SOLARIS10 directory tree
)
- FS type (type of fs to be mounted)
- fsck pass (is used by the fsck whether to check fs, when this field contains -, the fs isn't checked. WHen contain 0, UFS fs are not checked however non UFS fs are checked. When contains value >0 fs is always checked.
All fs with a value of 1 are checked one at a time in the order they appear in /etc/vfstab file.
When the fsck cmd is run on multiple UFS fs that have this field >1 and preen option -o p is used, the fsck automatically checks the fs on different disks in parallel to max efficiency . Otherwise the value of this field doesn't have any affect.)
- mount at boot (if yes, you enable mountall cmd at boot to mount file systems.)
- mount options (a coma separated list of options for the mount cmd. A dash indicates use of default options)
Structure of /etc/mnttab file.
# cat /etc/mnttab /dev/dsk/c0t0d0s0 / ufs rw,intr,largefiles,logging,xattr,onerror=panic,dev=780000 1309376599 /devices /devices devfs dev=4840000 1309376558 ctfs /system/contract ctfs dev=48c0001 1309376558 proc /proc proc dev=4880000 1309376558 mnttab /etc/mnttab mntfs dev=4900001 1309376558 swap /etc/svc/volatile tmpfs xattr,dev=4940001 1309376558 objfs /system/object objfs dev=4980001 1309376558 sharefs /etc/dfs/sharetab sharefs dev=49c0001 1309376558 /usr/lib/libc/libc_hwcap1.so.1 /lib/libc.so.1 lofs dev=780000 1309376582 fd /dev/fd fd rw,dev=4b40001 1309376599 swap /tmp tmpfs xattr,dev=4940002 1309376602 swap /var/run tmpfs xattr,dev=4940003 1309376602 /dev/dsk/c0t0d0s7 /export/home ufs rw,intr,largefiles,logging,xattr,onerror=panic,dev=780007 1309376634 -hosts /net autofs nosuid,indirect,ignore,nobrowse,dev=4c00001 1309376644 auto_home /home autofs indirect,ignore,nobrowse,dev=4c00002 1309376644The /etc/mnttab contains read-only info from the kernel about currently mounted fs on the local host.
Mount cmd
SYNTAX :
----------
mount -o options device mount_point | Option | Description |
|---|---|
read/write | Indicates whether reads and writes are allowed on the file system. |
setuid | Permits the execution of setuid programs in the file system. |
intr/nointr | Allows and forbids keyboard interrupts to kill a process that is waiting for an operation on a locked file system. |
logging | Indicates that logging is enabled for the ufs file system. This is the default for the Solaris 10 OS. |
largefiles | Allows for the creation of files larger than 2 Gbytes. A file system mounted with this option can contain files larger than 2 Gbytes. |
xattr | Supports extended attributes not found in standard UNIX attributes. |
onerror=action | Specifies the action that the ufs file system should take to recover from an internal inconsistency on a file system. An action can be specified as: |
panic | Causes a forced system shutdown. This is the default. |
lock | Applies a file system lock to the file system. |
umount | Forcibly unmounts the file system. |
Usage scenario :
-------------------
# mount /dev/dsk/c0t2d0s0 /export/home
Mount device with default options : read/write,setuid,intr,logging,largefiles,xattr,onerror
# mount -o ro,nosuid /dev/dsk/c0t2d0s0 /export/home
Mount device with multiple mount options.
# mount -o nolargefiles /dev/dsk/c0t2d0s0 /export/home
# mountall
Mount all fs listed in /etc/vfstab file which has mount at boot option yes.
mountall -l
Mount all local fs listed in /etc/vfstab file.
By default mount cmd assumes you always mount UFS fs type. When you want to mount different type you have to use mount -F fs type syntax. FS type must exist in one of 3 files : /etc/vfstab, /etc/default/fs, /etc/dfs/fstypes.
The default local file system type is specified in the /etc/default/fs file by the line entry LOCAL=fstype.
LOCAL=ufs
The first line entry in the /etc/dfs/fstypes file determines the default remote file system type.
nfs NFS Utilities
autofs AUTOFS Utilities
cachefs CACHEFS Utilities
# fstype /dev/rdsk/c0t2d0s0
ufs
Determine defualt fs type on particular device.
# mount -F hsfs -o ro /dev/dsk/c0t6d0s0 /cdrom
Mount CD-ROM when vold daemon is stopped.
# mount -F pcfs /dev/diskette /pcfs
MOunt fs from diskette.
Unmounts fs
Fs must be unmounted when it needs to be backedup or checked for inconsistency by fsck.
SYTNAX :
--------
umount device / mount_point
Usage scenario :
-----------------
# umount /dev/dsk/c0t2d0s0
Unmounts fs.
# unmountall
Unmounts all fs from /etc/mnttab file.
umount -l
Unmounts only local fs.
The /etc/mnttab file is read by the /usr/sbin/umountall command during the system shutdown sequence or when umountall is invoked from the command line. The umountall unmounts all file systems specified in the vfstab file except / (root), /usr, /proc, /dev/fd, /var, /var/run, and /tmp.
# fuser -cu /export/home
List all the PID that are accessing the fs.
# fuser -ck /export/home
Kill all PID that are accessing the fs, needed when trying to unmount fs but it displays message that is busy.
# umount -f /export/home
Force to unmount fs.
The file system is unmounted even if it contains open files. A forced unmount can result in loss of data and in zombie processes that are left running on the system. However, it is particularly useful for unmounting a shared file system if the remote file server is nonfunctional.
VOLD Volume Management Daemon
It is service that allows you to automatically mount cd/dvd, diskette into SOL10.
Volume Management (vold) features automatic detection of CD-ROMs. However, it does not detect the presence of a diskette that has been inserted in the drive until the volcheck command is run. This command instructs the vold daemon to check the diskette drive for any inserted media. Volume Management (vold) can mount ufs, pcfs, hsfs, and udfs file systems.
File | Description |
|---|---|
/etc/vold.conf | The Volume Management (vold) configuration file. This file defines items, such as what action should be taken when media is inserted or ejected, which devices are managed by Volume Management (vold), and which file system types are unsafe to eject. |
/etc/rmmount.conf | The rmmount command configuration file. The rmmount command is a removable media mounter that is executed by the Volume Management (vold) daemon whenever a CD-ROM or diskette is inserted. |
---------------------------
/etc/init.d/volmgt stop
Stop VOLD service.
/etc/init.d/volmgt start
Start VOLD sevice.
Accessing a diskette, cd/dvd without VOLD :
--------------------------------------------------------------------
1. Insert the media device.
2. Become the root user.
3. Create a mount point, if necessary.
4. Determine the file system type.
5. Mount the device by using the mount options listed in the following sections.
6. Work with files on the media device.
7. Unmount the media device.
8. Eject the media device.
9. Exit the root session.
