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HMCDRVFS(1) General Commands Manual HMCDRVFS(1)

NAME

hmcdrvfs - mount a FUSE file system for remote access to a DVD in a HMC DVD drive

SYNOPSIS

mounting: 
hmcdrvfs MOUNTPOINT [OPTIONS]



unmounting:




fusermount -u MOUNTPOINT













DESCRIPTION

Use the hmcdrvfs command for read-only access to files on a
  DVD in the DVD drive of an HMC.
  On the HMC, the DVD must be assigned to the
  LPAR within which your Linux instance runs. For
  z/VM guests, the DVD must be assigned to the
  LPAR where the z/VM hypervisor runs. With the
  DVD assigned to your Linux instance, this command creates a
  FUSE.HMCDRVFS file system with the content of the
  DVD at the specified mountpoint.







OPTIONS




General mount options



  
-o opt[,opt...]

  
FUSE or mount command options; for the FUSE
      options see below, for mount options see mount(8)

  
-h, --help

  
print usage information, then exit (see also DIAGNOSTICS)

  
-v, --version

  
print version information, then exit
    

  








Specific FUSE.HMCDRVFS options



  
-o hmclang=LANG

  
specify the language setting on the HMC; for valid values,
      see locale(1); for more information, see DIAGNOSTICS and
    EXAMPLES

  
-o hmctz=TZ

  
specify the time zone setting on the HMC; for valid values,
      see tzset(3); for more information, see DIAGNOSTICS and EXAMPLES
    

  








Applicable FUSE options (version 2.6)



  
-d, -o debug

  
enable debug output (implies -f)

  
-f

  
foreground operation

  
-s

  
disable multi-threaded operation

  
-o allow_other

  
allow access by other users

  
-o allow_root

  
allow access by root

  
-o nonempty

  
allow mounts over non-empty file/dir

  
-o default_permissions

  
enable permission checking by kernel

  
-o fsname=NAME

  
set file system name

  
-o subtype=TYPE

  
set file system type

  
-o max_read=N

  
set maximum size of read requests

  
-o direct_io

  
use direct I/O

  
-o kernel_cache

  
cache files in kernel

  
-o [no]auto_cache

  
enable caching based on modification times

  
-o umask=M

  
set file permissions (octal)

  
-o uid=N

  
set file owner

  
-o gid=N

  
set file group

  
-o entry_timeout=T

  
cache timeout for names (default: 1.0 second)

  
-o attr_timeout=T

  
cache timeout for attributes (default: 1.0 second)

  
-o ac_attr_timeout=T

  
auto cache timeout for attributes (default: attr_timeout)

  
-o max_readahead=N

  
set maximum readahead

  
-o async_read

  
perform reads asynchronously (default)

  
-o sync_read

  
perform reads synchronously

  
-o no_remote_lock

  
disable remote file locking

  
-o intr

  
allow requests to be interrupted

  
-o intr_signal=NUM

  
signal to send on interrupt
    

    

  










EXAMPLES

To mount the HMC drive DVD at /mnt/hmc
  without any special options use:





$ hmcdrvfs /mnt/hmc







In case the kernel module hmcdrv was not loaded in advance
    use:






# modprobe hmcdrv
# hmcdrvfs /mnt/hmc







To translate the UID and GID of files on the HMC
    drive DVD to your system users and groups along with
    overriding the permissions use for example:






$ hmcdrvfs /mnt/hmc -o uid=500 -o gid=1000 -o umask=0337







To speed up transfer rates to frequently accessed directories use
    the cache timeout option:






$ hmcdrvfs /mnt/hmc -o entry_timeout=60






If the HMC is in a different timezone and is configured for a
  different language use, for example:





$ hmcdrvfs /mnt/hmc -o hmclang=de_DE -o hmctz=Europe/Berlin







or disregarding any daylight saving time, specifying hours west of
    Prime Meridian (UTC):






$ hmcdrvfs /mnt/hmc -o hmclang=de_DE -o hmctz="GMT-1"







To unmount the HMC drive DVD mounted
    on /mnt/hmc use:






$ fusermount -u /mnt/hmc







It is also possible to mount by using fstab(5). Specify the
    mount point and associated mount options in /etc/fstab, for
  example:






hmcdrvfs /mnt/hmc fuse ro,noatime,allow_other,uid=500,gid=1000







You can then mount the file system with this command:






# mount /mnt/hmc













FILES

Some general options about mount policy can be set in the /etc/fuse.conf
  file. These options are:


  
mount_max=NNN

  
Set the maximum number of FUSE mounts allowed to non-root
      users. The default is 1000.

  
user_allow_other

  
Allow non-root users to specify the allow_other or
      allow_root mount options.
    

  








DIAGNOSTICS



  
1.

  
The FUSE.HMCDRVFS file system needs access to device node
      /dev/hmcdrv. This node is created automatically when the
      hmcdrv kernel module is loaded (see Linux kernel configuration
      option CONFIG_HMC_DRV). The user process that runs the
      hmcdrvfs command must have sufficient privileges to read from and
      write to node /dev/hmcdrv. Use the commands chown(1),
      chgrp(1) and/or chmod(1) on node /dev/hmcdrv to
      ensure this condition.
    

  

  
2.

  
In addition to the required permissions, there are some environmental
      requirements:







  
-

  
In a z/VM environment, the z/VM guest
      virtual machine must have at least privilege class B.

  
-

  
For Linux in LPAR mode, the LPAR activation
      profile must allow issuing SCLP requests.

  
-

  
On the HMC, the DVD must be assigned to the
      associated system image (use menu Access Removable
    Media).









  
3.

  
The FUSE.HMCDRVFS file system maintains a file attributes
      cache, with an aging timeout. This timeout is related to the
      entry_timeout and attr_timeout FUSE options.
      Its value exceeds the greater of the two, entry_timeout and
      attr_timeout, by 30 - 60 seconds. This timeout affects the
      performance of the FUSE.HMCDRVFS file system.







  
4.

  
Different language and time zone settings on the HMC and
      your Linux instance can result in incorrect file modification
    information.







  
-

  
Use the hmclang specific FUSE.HMCDRVFS option if the
      language settings of the HMC and your Linux instance do not
      match. Correctly setting this option prevents incorrect file modification
      dates in the file details. Omitting the hmclang option can result
      in incorrect dates of the form 01-01-YYYY, with misleading values for the
      day and month.

  
-

  
Use the hmctz specific FUSE.HMCDRVFS option if the
      time zone settings of the HMC and your Linux instance do
      not match. Correctly setting this option prevents incorrect file
      modification times in the file details. Omitting hmctz, an
      incorrect specification, or a missing time zone description file can
      result in modification times that differ up to 25 hours from the correct
      times. Specifications that cannot be interpreted result in GMT/UTC being
      set. If the HMC is set to GMT/UTC, specify
      hmctz="".









  
5.

  
The following generic mount options from mount(8) are ignored:







  
-w, --rw, -o rw

  
mount the file system read/write

  
-o atime

  
update inode access times on this file system









  
6.

  
The following FUSE mount options from mount.fuse(8)
      are ignored:







  
-o hard_remove

  
immediate removal

  
-o negative_timeout

  
cache timeout for deleted names

  
-o max_write=N

  
set maximum size of write requests

  
-o atomic_o_trunc

  
enable atomic open+truncate support

  
-o big_writes

  
enable larger than 4kB writes

  
-o subdir=DIR

  
prepend this directory to all paths

  
-o use_ino

  
let file system set inode numbers

  
-o readdir_ino

  
try to fill in d_ino in readdir












SEE ALSO

tzset(3), locale(1), fusermount(1), fstab(5),
  mount(8), mount.fuse(8) lshmc(8), and Linux on System z:
  Device Drivers, Features and Commands






  

    Mar 2015
    s390-tools