filesystem limitation

[Juergen Nagel_1]

Is it possible to store 180000 files in one directory? Exists a limitation? What is the best filesystem to do this? The files are approximately 25k.
Thanks

[eran maor · Accepted solution]

Hi

if you are working on a vxfs file system that have dym. inode increase you can create this number of file ( not open files !!)

see answer :
http://forums.itrc.hp.com/cm/QuestionAnswer/1,1150,0xadbf53921f1ad5118fef0090279cd0f9,00.html

[Wodisch]

Hello Juergen,

the sizes of the files or NOT a problem, but the amount of
space needed for all those names in a single directory
will slow down everything accessing those files!!!

UN*X reads and writes directories at once - I am getting
tired of telling this to everybody ;-) Ask Eran - I showed
him a couple of weeks ago in Tel Aviv by doing this:

f="This-is-a-very-long-file-name-and-is-just-used-to"
f="${f}-show-what-is-happening-to-you-when-you"
f="${f}-use-huge-directories-on-any-UNIX-system"
mkdir /tmp/bigdir
cd /tmp/bigdir
ls -ld $PWD
n=0
while [ $n -lt 100000 ]; do touch $f.$n; ((n = n +1)); done
ls -ld $PWD

while this is running, watch the output of "sar -a 1 1000"
in another terminal window - especially look for the
column "dirbk/s" - it shows the amount of directory blocks
processed. If you have a recent system, that be some
dozen megabytes per second - on directories alone!

Hence, think about storing many, many files in a single
directory!

HTH,
Wodisch

[TrustNo1]

Hi Juergen,
Another aspect you should consider, is backup and restore of such large amount of files.
Depending on which backup solution you use this can very. We use Omniback, and I can tell you from experience, there are many things to consider when backing up such a large amount of files, memory, database size, etc..
We have one with 200000+, and if I had known then what I know now, it would have never happened.
I believe the max. amount of files in one directory is 2 million, but DO NOT even consider attempting to backup-restore such a beast, I'm not for sure it would even be possible! Consider a tiered directory layout, it would be well worth the effort, and after all, planning is half the fun!
~jdk

[Wodisch]

Hello,

IIRC, there is a limit for the amount of directories on a
single VxFS...

Wodisch