.. -*- coding: utf-8; -*-

==============

 File system.

==============

.. contents::

   :local:

Supported FS.

=============

List of supported by current Linux kernel FSes::

  $ cat /proc/filesystems

FS stats

========

Free space::

  $ df

Free space in MB::

  $ df -m

Free space in human readable format::

  $ df -h

Number of free nodes::

  $ df -i

FS limits

=========

``ext4`` uses 32-bit inode numbers so number of files limited to 2^32.

===== ==== ====== ======= ======= ========

   fs name  inode sub-dir    file fs total

===== ==== ====== ======= ======= ========

 ext2  255                  2 TiB   16 TiB

 ext3  255          32000   2 TiB   16 TiB

 ext4  255   2^32   64000  16 TiB   16 TiB

btrfs  255   2^64       -  16 EiB   16 EiB

fat32  255 268e+6    2^16   2 GiB    8 TiB

 ntfs  255   2^32    2^32  16 TiB  256 TiB

  xfs  255                100 TiB  100 TiB

 gfs2  255                100 TiB  100 TiB

===== ==== ====== ======= ======= ========

https://en.wikipedia.org/wiki/Comparison_of_file_systems#Limits

  FS limits.

Make label on FAT32 volume.

===========================

The volume name can be up to 11 characters long::

  $ sudo mlabel -i /dev/<device> ::my-label

or when create FAT32 file system::

  $ sudo mkdosfs -n <vol-name> /dev/<device>

Convert file name coding.

=========================

::

  $ convmv --nosmart -f cp-1251 -t utf-8 -r $dir

How get file time attributes.

=============================

POSIX define 3 file time attributes: atime (access time, only a few OS/fs update

this parameter), ctime (attribute/inode modification time), mtime (modification

time).

To get time you can use 'ls' command but it print time in locale dependent

irregular form::

  $ ls -l file.txt      # last file modification

  $ ls -lc file.txt     # last file status modification

  $ ls -lu file.txt     # last access

GNU coreutils provide more robust 'stst' utility::

  $ stat -c %Y file.txt # last file modification

  $ stat -c %Z file.txt # last file status modification

  $ stat -c %X file.txt # last access

POSIX file name restriction.

============================

Windows file name restriction.

==============================

  http://msdn.microsoft.com/en-us/library/aa365247.aspx

                Naming Files, Paths, and Namespaces

How get UUID and label?

=======================

Include UUID (Universally Unique Identifier) and labels::

  $ ls -l /dev/disk/by-uuid/

  lrwxrwxrwx 1 root root 10 2010-11-01 23:41 46B6-1FD4 -> ../../sdb2

  lrwxrwxrwx 1 root root 10 2010-11-01 23:41 4C30299030298256 -> ../../sda1

  $ ls -l /dev/disk/by-label/

  lrwxrwxrwx 1 root root 10 2010-11-01 23:41 bin -> ../../sda3

  lrwxrwxrwx 1 root root 10 2010-11-01 23:41 inst -> ../../sda2

  lrwxrwxrwx 1 root root 10 2010-11-01 23:41 media -> ../../sdc5

  $ sudo vol_id /dev/dm-2

  ID_FS_USAGE=filesystem

  ID_FS_TYPE=ext3

  ID_FS_VERSION=1.0

  ID_FS_UUID=f7484fc9-75ec-4e46-8539-50b1e371b7ef

  ID_FS_UUID_ENC=f7484fc9-75ec-4e46-8539-50b1e371b7ef

  ID_FS_LABEL=

  ID_FS_LABEL_ENC=

  ID_FS_LABEL_SAFE=

  $ /sbin/blkid     ## from 'e2fsprogs' package

  /dev/sdc2: UUID="46B6-1FD4" TYPE="vfat"

  /dev/sdb2: TYPE="ntfs" UUID="BC48D3FD48D3B47C" LABEL="inst"

  /dev/sda5: UUID="5240AED140AEBB5D" LABEL="music" TYPE="ntfs"

  /dev/sdc1: UUID="81c4444f-0b70-429a-9d97-8c13e8651f5b" TYPE="ext3"

  /dev/sdc3: UUID="KOpHWz-clDR-2MqV-vAkE-cPvY-uZrY-kjYJIb" TYPE="lvm2pv"

  $ udevinfo --query=all --name /dev/sdb    ## from 'udev' package

  P: /block/sdb

  N: sdb

  S: disk/by-id/ata-WDC_WD1600JS-00MHB0_WD-WCANM5835587

  S: disk/by-id/scsi-SATA_WDC_WD1600JS-00_WD-WCANM5835587

  S: disk/by-path/pci-0000:00:08.0-scsi-1:0:0:0

  E: ID_VENDOR=ATA

  E: ID_MODEL=WDC_WD1600JS-00M

  E: ID_REVISION=02.0

  ...

How set UUID and label?

=======================

For ext2/ext3 fs::

  $ sudo tune2fs /dev/hdb1 -U `uuid`

Linux fs under Windows.

=======================

Ext2Fsd.

--------

Ext2Fsd is an open source linux ext3/ext4 file system driver for Windows systems

(NT/2K/XP/Win7/Win8, X86/AMD64) and only alive project.

  http://www.ext2fsd.com/

    Home page.

  http://sourceforge.net/projects/ext2fsd/

    Sourceforge home page.

Ext2 IFS.

---------

It provides Windows NT4.0/2000/XP/2003/Vista/2008 with full access to Linux Ext2

volumes (read access and write access). This may be useful if you have installed

both Windows and Linux as a dual boot environment on your computer.

The "Ext2 Installable File System for Windows" software is freeware.

After install use 'ifsdrives.cpl' control panel to modify settings.

  http://www.fs-driver.org/

                home page

rfstool.

--------

Allows you to access ReiserFS partitions from a Windows 95/98/ME/NT/2000/XP

system. It also allows you to access ReiserFS partitions from Linux. It is a

complete rewrite of the ReiserFS functions needed to list directories, copy

files, and backup metadata.

  http://p-nand-q.com/e/reiserfs.html

                home page

  http://freshmeat.net/projects/rfstool/

                Freshmeat home page.

Summary files size.

===================

::

  $ find . -type f -iname "*.log" -print0 | du --files0-from=- -c -m | tail -n 1 \

      | (read first rest; echo $first)

Mount NTFS in Linux.

====================

Mount in rw mode::

  $ man 8 ntfs-3g

  $ cat /etc/fstab

  ...

  UUID=D474CB9874CB7C2C /mnt/winbin ntfs-3g rw,default_permissions,gid=1000,fmask=113,dmask=002,noatime,silent 0 0

  ...

Stop fsck running every 27 boots.

=================================

Check current settings::

  $ tune2fs -l /dev/$DISK

and tune them::

  $ tune2fs -c 0 /dev/$DISK

  $ tune2fs -i 2w /dev/$DISK

Or disable checks in ``/etc/fstab`` completely (by setting last colon to ``0``

value)!