supports the find command traversing directory file trees - i.e., searching and locating files.
Assuming you want to keep the command you already have (and I am not sue that Rudi's suggested test is valid because of file and directory caching ):
A limiting factor is known to be the number of sub-directories in the file tree, and possibly the number of available open file descriptors - a per process limit.
If you can parallelize your code using several processes it may improve performance. I'm not sure this will help much because it depends on the number of sub-directories being large to gain any benefit. The developers who write system code try to maximize throughput.
What I'm saying is: performance enhancement work is subjective and often a misplaced resource and a waste of programmer time.
Suppose your command runs in one minute in production. Then you work hard and get it down to 35 seconds. The user perception of "slow" will still be there, so you have to get it down to maybe 6 seconds to make users happy and see it as "faster". In this case getting an order of magnitude improvement may not be possible.
And in this case you would have to do something about directory caching messing up testing because (you check this yourself) once you open a directory the system caches it for speedier access. Use the time command and rerun the command to see what I mean:
This User Gave Thanks to jim mcnamara For This Post:
Hi ,
i'm searching for files over many Aix servers with rsh command using this request :
find /dir1 -name '*.' -exec ls {} \;
and then count them with "wc"
but i would improve this search because it's too long and replace directly find with ls command but "ls *. " doesn't work.
and... (3 Replies)
I have written a code using AWK & sed to compare two files.
The structure of the files is like this"
Format is this:
<bit code> <file code> <string>
Follwoed by any numbers of properties lines whic start with a "space"
10101010101111101 XX abcd a
AS sasa
BS kkk
1110000101010110 XX... (1 Reply)
I'm using sed to do find and replace. But since the file is huge and i have more than 1000 files to be searched, the script is taking a lot of time. Can somebody help me with a better sed command. Below is the details.
Input:
1
1
2
3
3
4
5
5
Here I know the file is sorted.
... (4 Replies)
Hi,
I wanted to run a particlar script for every 20 minutes. I dont have crontab in my server. Hence i ran this script in a loop by providing the command sleep 1200
Now i wanted to know is there any performance issue if this job keeps on execute in the server.
Thanks,
Puni (1 Reply)
Hi,
I have created a shell script for Server Log Automation Process. I have used
find xargs grep command to search the string.
for Example,
find -name | xargs grep "816995225" > test.txt .
Here my problem is,
We have lot of records and we want to grep the string... (4 Replies)
Hello All,
We have a working script which identifies and kills ipcs resources which havent been correctly killed during normal shutdowns.
It is working fine and dandy however there are some issues now.
Environment:
SunOS 5.10 Generic_148888-03 sun4u sparc SUNW,SPARC-Enterprise
... (4 Replies)
I have a ksh shell script and i need to pass arguments which are generated by data pulled from a database.
When the argument to the shell script is too long (about 4000 charecters) the below is the issue observed.
I copy the command which is 4000 charecters long from the logs and paste it... (7 Replies)
Discussion started by: mohtashims
7 Replies
LEARN ABOUT OPENSOLARIS
tmpfs
tmpfs(7FS) File Systems tmpfs(7FS)NAME
tmpfs - memory based file system
SYNOPSIS
#include <sys/mount.h>
mount (special, directory, MS_DATA, "tmpfs", NULL, 0);
DESCRIPTION
tmpfs is a memory based file system which uses kernel resources relating to the VM system and page cache as a file system. Once mounted, a
tmpfs file system provides standard file operations and semantics. tmpfs is so named because files and directories are not preserved across
reboot or unmounts, all files residing on a tmpfs file system that is unmounted will be lost.
tmpfs file systems can be mounted with the command:
mount -F tmpfs swap directory
Alternatively, to mount a tmpfs file system on /tmp at multi-user startup time (maximizing possible performance improvements), add the
following line to /etc/vfstab:
swap -/tmp tmpfs - yes -
tmpfs is designed as a performance enhancement which is achieved by caching the writes to files residing on a tmpfs file system. Perfor-
mance improvements are most noticeable when a large number of short lived files are written and accessed on a tmpfs file system. Large com-
pilations with tmpfs mounted on /tmp are a good example of this.
Users of tmpfs should be aware of some constraints involved in mounting a tmpfs file system. The resources used by tmpfs are the same as
those used when commands are executed (for example, swap space allocation). This means that large sized tmpfs files can affect the amount
of space left over for programs to execute. Likewise, programs requiring large amounts of memory use up the space available to tmpfs. Users
running into this constraint (for example, running out of space on tmpfs) can allocate more swap space by using the swap(1M) command.
Another constraint is that the number of files available in a tmpfs file system is calculated based on the physical memory of the machine
and not the size of the swap device/partition. If you have too many files, tmpfs will print a warning message and you will be unable to
create new files. You cannot increase this limit by adding swap space.
Normal file system writes are scheduled to be written to a permanent storage medium along with all control information associated with the
file (for example, modification time, file permissions). tmpfs control information resides only in memory and never needs to be written to
permanent storage. File data remains in core until memory demands are sufficient to cause pages associated with tmpfs to be reused at which
time they are copied out to swap.
An additional mount option can be specified to control the size of an individual tmpfs file system.
SEE ALSO df(1M), mount(1M), mount_tmpfs(1M), swap(1M), mmap(2), mount(2), umount(2), vfstab(4)
System Administration Guide: Basic Administration
DIAGNOSTICS
If tmpfs runs out of space, one of the following messages will display in the console.
directory: File system full, swap space limit exceeded
This message appears because a page could not be allocated while writing to a file. This can occur if tmpfs is attempting to write more
than it is allowed, or if currently executing programs are using a lot of memory. To make more space available, remove unnecessary
files, exit from some programs, or allocate more swap space using swap(1M).
directory: File system full, memory allocation failed
tmpfs ran out of physical memory while attempting to create a new file or directory. Remove unnecessary files or directories or install
more physical memory.
WARNINGS
Files and directories on a tmpfs file system are not preserved across reboots or unmounts. Command scripts or programs which count on this
will not work as expected.
NOTES
Compilers do not necessarily use /tmp to write intermediate files therefore missing some significant performance benefits. This can be
remedied by setting the environment variable TMPDIR to /tmp. Compilers use the value in this environment variable as the name of the direc-
tory to store intermediate files.
swap to a tmpfs file is not supported.
df(1M) output is of limited accuracy since a tmpfs file system size is not static and the space available to tmpfs is dependent on the swap
space demands of the entire system.
SunOS 5.11 9 Oct 1990 tmpfs(7FS)