Confused with File System Concepts Post: 44756

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Operating Systems AIX Confused with File System Concepts Post 44756 by Perderabo on Wednesday 10th of December 2003 12:41:09 PM

12-10-2003

Administrator Emeritus

I don't know aix, but I took a quick look at some web sites and it looks like aix is using an upgraded version of the McKusick filesystem. So I'll take a quick stab at some of this...

NBPI
An inode is a thing that you need to create a file. If a filesystem has 1000 inodes, then it can have 1,000 files. You want to have too many inodes. When you run out of disk space, you will have some unused inodes. That is better than unused disk space with no inodes left to use it. NBPI is number of bytes per inode. Think of it as the average expected file size. By having a default expressed this way, if the filesystem doubles, so do the inodes.

Allocation Group
A filesystem is big so it get chopped up into a few sections called allocation groups. Think about a file that is growing...it needs another data block. You don't want any data block, you want one close by. So the system tries to keep the file in the same allocation group. In fact it tries to keep all of the files in a directory (not subdirectory) in the same allocation unit. Allocation units should be large enough for this to be possible most of the time.

allocation unit
This is the smallest piece of data that can be assigned to a file. A one byte file will use one allocation unit.

That's a quick rundown of these terms. But if you don't understand them all, just take the default values for everything.

Note to freaked out file system gurus...I know that I'm over-simplifying. I think that's what the OP wanted.

Perderabo

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dxfileshare

dxfileshare(8)						      System Manager's Manual						    dxfileshare(8)

NAME

       dxfileshare - Exports local directories and mounts directories from the network

SYNOPSIS

       /usr/bin/X11/dxfileshare

DESCRIPTION

       Use the File Sharing application, dxfileshare, to: Export (or share) local UNIX directories to the network Stop exporting UNIX local direc-
       tories to the network Specify which directories mounted from the network are to be remounted every time the system is  rebooted,  that  is,
       add  an entry to the /etc/fstab file Add, change, or delete NFS entries from the /etc/exports file Share local UNIX directories with a per-
       sonal computer (PC) when Advanced Server for UNIX is installed on your system Display local directories that are shared (exported) with the
       network Display network mounts (directories that can be mounted from the network)

       The File Sharing application can also be invoked from the CDE Application Manager from the following categories:

       Application Group:	System_Admin
       System Admin Subgroup:	Daily Admin

       Online help is available for the File Sharing application by clicking on any Help button or using the Help pull-down menu.

RESTRICTIONS

       You  must  have root privileges to use certain features of File Sharing.  Namely, the ability to export (or share) a directory or to modify
       the properties of a directory that is already being exported.

       You must have Advanced Server for UNIX installed on your system to share local directories with PCs.

FILES

       Defaults that are shared by the graphical and command line user interface. File Sharing uses the same file as the Host Manager application.
       File  Sharing  application File Sharing help volume Directory containing File Sharing application icons Application defaults file that sets
       the default values for the X resources File Sharing message catalog Message catalog containing File Sharing location IDs for  on-item  help
       i18n_motif_shared_text.cat

	      Message catalog containing application-independent messages i18n_motif_shared_text_LocIds.cat

	      Message catalog containing application-independent location IDs for on-item help

SEE ALSO

       Commands: X(1X), automount(8), bcheckrc(8), mount(8), mountd(8), showmount(8), umount(8)

       Functions: getfsstat(2), getmntinfo(3), getmntinfo_r(3), mount(2), mount(2sv), umount(2), umount(2sv), umount(3)

       Files: exports(4), fstab(4), mountdtab(4)

       Tru64 UNIX System Administration

       ASU Installation and Administration Guide

       ASU Concepts and Planning Guide

																    dxfileshare(8)