| Hard Link | Soft Link / symbolic Link |
| If the inode entries are the same and if the count is 2 then they are hard linked. | if you see filename --> linked_directory
Then its a symbolic link. |
| la –lia | ls -a |
| ln <source> <target file> (without the option –s which stands for soft link). | ln -s <source> <target file> (with the option –s which stands for soft link). |
| It is essentially create identical copies, No matter which one you update, both of them will get updated | |
both links must reside on the same filesystem,
the source file must exist | that are not applicable to softlinks (source and target can be on seperate file systems, source does not have to exist, etc.)
additional I/O necessary to complete file access, additional storage taken up by softlink file's data |
| | A "soft" link does not increase the inode count for the referenced file, a "hard" link does.
If the count = 1, it's a soft link. If the count is > 1, it's a hard link. |
Example of Viewing existing Hard link
ls –lia
1. Same iNode number : 245787
2. After permission column it lists 2
| oracle@test:/app/oracle/product/11.2.0.3/grid/network/admin $ ls -lia
total 120
153544 drwxr-xr-x 4 oracle dba 1024 Sep 12 04:27 ./
153543 drwxr-xr-x 11 oracle dba 1024 Aug 27 17:39 ../
250089 drwxr-xr-x 2 oracle dba 1024 Oct 17 12:58 OLD/
167535 -rw-r--r-- 1 oracle dba 1580 Sep 4 05:01 listener.old
153001 -rw-r--r-- 1 oracle dba 4524 Oct 17 13:01 listener.ora
159439 -rw-r--r-- 1 oracle dba 205 May 11 2011 shrept.lst
167531 -rw-r--r-- 1 oracle dba 881 Aug 27 18:17 sqlnet.ora
245787 -rw-r--r-- 2 oracle dba 43224 Sep 25 01:38 tnsnames.ora
oracle@test:/app/oracle/product/11.2.0.3/grid/network/admin $ cd $TNS_ADMIN
oracle@test:/app/oracle/product/11.2.0.3/db/network/admin $ ls -lia
total 102
168564 drwxr-xr-x 4 oracle dba 1024 Sep 7 00:29 ./
168563 drwxr-xr-x 11 oracle dba 1024 Aug 27 18:11 ../
158839 drwxr-xr-x 2 oracle dba 1024 Sep 25 01:35 OLD/
164004 -rw-r--r-- 1 oracle dba 2690 Sep 7 00:29 listener.ora
168565 drwxr-xr-x 2 oracle dba 96 Aug 27 18:00 samples/
178592 -rw-r--r-- 1 oracle dba 205 May 11 2011 shrept.lst
245790 -rw-r--r-- 1 oracle dba 881 Aug 27 18:17 sqlnet.ora
245787 -rw-r--r-- 2 oracle dba 43224 Sep 25 01:38 tnsnames.ora
|
Example of viewing SoftLink
| oracle@test1:/app/grid/product/11.2.0.3/network/admin $ ls -lia
total 82
343 drwxr-xr-x 4 oracle dba 1024 Aug 24 17:01 ./
342 drwxr-xr-x 11 oracle dba 1024 Aug 9 09:55 ../
16349 drwxr-xr-x 2 oracle dba 1024 Sep 7 12:43 OLD/
12489 -rw-r--r-- 1 oracle dba 186 Aug 9 10:26 endpoints_listener.ora
12165 -rw-r--r-- 1 oracle dba 1568 Sep 7 12:46 listener.ora
12488 -rw-r--r-- 1 oracle dba 534 Aug 9 10:26 listener.ora.bak.usfspfd1
12477 -rw-r--r-- 1 oracle dba 368 Aug 9 10:26 listener12080910AM2605.bak
344 drwxr-xr-x 2 oracle dba 96 Aug 9 09:49 samples/
5108 -rw-r--r-- 1 oracle dba 205 May 11 2011 shrept.lst
22677 -rw-r--r-- 1 oracle dba 561 Aug 13 18:33 sqlnet.ora
12487 -rw-r--r-- 1 oracle dba 646 Aug 9 10:26 sqlnet.ora_temp
22674 -rw-r--r-- 1 oracle dba 29904 Aug 23 16:09 tnsnames.old
42504 lrwxr-xr-x 1 oracle dba 58 Aug 24 17:01 tnsnames.ora@ -> /app/oracle/product/11.2.0.3/db/network/admin/tnsnames.ora
oracle@test1:/app/grid/product/11.2.0.3/network/admin $ cd $TNS_ADMIN
oracle@test1:/app/oracle/product/11.2.0.3/db/network/admin $ ls -lia
total 82
150342 drwxr-xr-x 4 oracle dba 1024 Aug 21 16:29 ./
150341 drwxr-xr-x 11 oracle dba 1024 Aug 9 11:36 ../
214228 drwxr-xr-x 2 oracle dba 1024 Oct 30 22:55 OLD/
268044 -rw-r----- 1 oracle dba 3554 Aug 14 14:43 listener.ora
150343 drwxr-xr-x 2 oracle dba 96 Aug 9 11:23 samples/
170627 -rw-r--r-- 1 oracle dba 205 May 11 2011 shrept.lst
268082 -rw-r--r-- 1 oracle dba 561 Aug 14 14:50 sqlnet.ora
266832 -rw-r--r-- 1 oracle dba 32061 Oct 9 10:42 tnsnames.ora
|
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