Freebsd mount ufs file system

For ZFS, I believe you will need to boot the system from usb or cd. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Learn more. Asked 6 years, 5 months ago. Active 6 years, 5 months ago. Viewed 6k times. Improve this question. Is it zfs or ufs? Add a comment. Have some familiarity with disks , storage, and device names in FreeBSD.

Kernel support for ext2 file systems has been available since FreeBSD 2. In FreeBSD 8. Since FreeBSD 9. The ext2fs 5 driver allows the FreeBSD kernel to both read and write to ext2 file systems. This driver can also be used to access ext3 and ext4 file systems. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Helping communities build their own LTE networks. Podcast Making Agile work for data science.

Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. Linked 5. Related 4. Hot Network Questions. To determine the device name of the burner, use -scanbus which might produce results like this:. Locate the entry for the CD burner and use the three numbers separated by commas as the value for dev. Refer to the manual page for cdrecord for other ways to specify this value and for information on writing audio tracks and controlling the write speed.

Use the numeric values for scbus , target , and lun. For this example, 1,0,0 is the device name to use. In order to produce a data CD, the data files that are going to make up the tracks on the CD must be prepared before they can be burned to the CD.

The simplest usage is to specify the name of the ISO file to create and the path to the files to place into the ISO file system:. This command maps the file names in the specified path to names that fit the limitations of the standard ISO file system, and will exclude files that do not meet the standard for ISO file systems.

A number of options are available to overcome the restrictions imposed by the standard. The last option of general use is -b. This is used to specify the location of a boot image for use in producing an "El Torito" bootable CD.

This option takes an argument which is the path to a boot image from the top of the tree being written to the CD. By default, mkisofs creates an ISO image in "floppy disk emulation" mode, and thus expects the boot image to be exactly , or KB in size. Some boot loaders, like the one used by the FreeBSD distribution media, do not use emulation mode. In this case, -no-emul-boot should be used. There are many other options available for mkisofs to fine-tune its behavior. Refer to mkisofs 8 for details.

It is possible to copy a data CD to an image file that is functionally equivalent to the image file created with mkisofs. To do so, use dd with the device name as the input file and the name of the ISO to create as the output file:.

Once an ISO has been burned to a CD, it can be mounted by specifying the file system type, the name of the device containing the CD, and an existing mount point:. Since mount assumes that a file system is of type ufs , an Incorrect super block error will occur if -t cd is not included when mounting a data CD. While any data CD can be mounted this way, disks with certain ISO extensions might behave oddly.

For example, Joliet disks store all filenames in two-byte Unicode characters. If some non-English characters show up as question marks, specify the local charset with -C. This can be done either by adding this line to loader. Occasionally, Device not configured will be displayed when trying to mount a data CD. This usually means that the CD drive has not detected a disk in the tray, or that the drive is not visible on the bus.

It can take a couple of seconds for a CD drive to detect media, so be patient. To resolve this, a custom kernel can be created which increases the default SCSI delay. This tells the SCSI bus to pause 15 seconds during boot, to give the CD drive every possible chance to answer the bus reset. This is known as burning a raw data CD and some people do this for backup purposes. This type of disk can not be mounted as a normal data CD.

In order to retrieve the data burned to such a CD, the data must be read from the raw device node. For example, this command will extract a compressed tar file located on the second CD device into the current working directory:.

To duplicate an audio CD, extract the audio data from the CD to a series of files, then write these files to a blank CD. If the FreeBSD version is less than This command can be used to extract all of the audio tracks, with each track written to a separate WAV file in the current working directory:. A device name does not need to be specified if there is only one CD device on the system. Refer to the cdda2wav manual page for instructions on how to specify a device and to learn more about the other options available for this command.

Make sure that 2,0 is set appropriately, as described in Burning a CD. This format is write once. A single layer recordable DVD can hold up to 4,,, bytes which is actually 4.

A distinction must be made between the physical media and the application. Before choosing the type of media, ensure that both the burner and the DVD-Video player are compatible with the media under consideration.

To perform DVD recording, use growisofs 1. This support is not needed if the burner uses the USB interface. Since growisofs 1 is a front-end to mkisofs , it will invoke mkisofs 8 to create the file system layout and perform the write on the DVD. This means that an image of the data does not need to be created before the burning process. Refer to mkisofs 8 for more details. For the initial session recording, -Z is used for both single and multiple sessions.

Using -dvd-compat indicates that the disk will be closed and that the recording will be unappendable. The write speed should be detected and automatically set according to the media and the drive being used. Refer to growisofs 1 for example usage. In order to support working files larger than 4. This is required only when creating an ISO image file or when writing files directly to a disk.

Otherwise it will look as if it contains corrupted files. When an ISO image already contains large files, no additional options are required for growisofs 1 to burn that image on a disk.

If an image of the DVD-Video file system already exists, it can be burned in the same way as any other image. This option implies the -dvd-compat growisofs 1 option.

It is recommended to let growisofs 1 take care of this automatically whenever appropriate. Instead, write over the previous recording like this:. This operation consists of merging a new session to the existing one as it is not considered to be multi-session writing.

The same mkisofs 8 options used to burn the initial session should be used during next writes. However, a non-virgin DVD-RW in sequential format needs to be blanked before writing a new initial session. One should instead use restricted overwrite mode with any DVD-RW as this format is more flexible than the default of incremental sequential.

To append some data to a previous recording, use -M with growisofs 1. However, if data is appended on a DVD-RW in incremental sequential mode, a new session will be created on the disc and the result will be a multi-session disc.

Instead, overwrite the disc with -Z. It is also possible to grow an existing ISO file system written on the disc with -M. The result will be a one-session DVD. The result will be a single-session disc. Use this method to add data after an initial write on these types of media. Since some space on the media is used between each session to mark the end and start of sessions, one should add sessions with a large amount of data to optimize media space.

In this example, the whole disk space will be formatted with a standard UFS2 file system:. The DVD device, acd0 , must be changed according to the configuration. A floppy disk needs to be low-level formatted before it can be used.

This is usually done by the vendor, but formatting is a good way to check media integrity. To low-level format the floppy disk on FreeBSD, use fdformat 1. When using this utility, make note of any error messages, as these can help determine if the disk is good or bad. After low-level formatting the disk, create a disk label as it is needed by the system to determine the size of the disk and its geometry.

To write the disk label, use bsdlabel 8 :. The floppy is now ready to be high-level formatted with a file system. The disk is now ready for use. These file systems are implemented as user space programs which interact with the fusefs 5 kernel module via a well defined interface.

Before using a FUSE file system we need to load the fusefs 5 kernel module:. Use sysrc 8 to load the module at startup:. Suppose a USB disk is plugged in. The disk partition information can be viewed with gpart 8 :. Implementing a backup plan is essential in order to have the ability to recover from disk failure, accidental file deletion, random file corruption, or complete machine destruction, including destruction of on-site backups.

The backup type and schedule will vary, depending upon the importance of the data, the granularity needed for file restores, and the amount of acceptable downtime.

Some possible backup techniques include:. Archives of the whole system, backed up onto permanent, off-site media. This provides protection against all of the problems listed above, but is slow and inconvenient to restore from, especially for non-privileged users. File system snapshots, which are useful for restoring deleted files or previous versions of files. Typically, a mix of backup techniques is used. For example, one could create a schedule to automate a weekly, full system backup that is stored off-site and to supplement this backup with hourly ZFS snapshots.

In addition, one could make a manual backup of individual directories or files before making file edits or deletions. This section describes some of the utilities which can be used to create and manage backups on a FreeBSD system.

These utilities work at the disk block level, below the abstractions of the files, links, and directories that are created by file systems. Unlike other backup software, dump backs up an entire file system and is unable to backup only part of a file system or a directory tree that spans multiple file systems.

Instead of writing files and directories, dump writes the raw data blocks that comprise files and directories. The default parameters assume a backup to a 9-track tape, rather than to another type of media or to the high-density tapes available today. These defaults must be overridden on the command line. It is possible to backup a file system across the network to a another system or to a tape drive attached to another computer. While the rdump 8 and rrestore 8 utilities can be used for this purpose, they are not considered to be secure.

Instead, one can use dump and restore in a more secure fashion over an SSH connection. Several built-in utilities are available for backing up and restoring specified files and directories as needed. A good choice for making a backup of all of the files in a directory is tar 1. Switches can be used to instead specify the name of a backup file.

When creating a backup file, make sure that the backup is not saved to the same directory that is being backed up. To restore the entire backup, cd into the directory to restore into and specify the name of the backup. Note that this will overwrite any newer versions of files in the restore directory. When in doubt, restore to a temporary directory or specify the name of the file within the backup to restore.

There are dozens of available switches which are described in tar 1. This utility also supports the use of exclude patterns to specify which files should not be included when backing up the specified directory or restoring files from a backup. To create a backup using a specified list of files and directories, cpio 1 is a good choice. Unlike tar , cpio does not know how to walk the directory tree and it must be provided the list of files to backup.

For example, a list of files can be created using ls or find. A backup utility which tries to bridge the features provided by tar and cpio is pax 1. Over the years, the various versions of tar and cpio became slightly incompatible.

While tape technology has continued to evolve, modern backup systems tend to combine off-site backups with local removable media. In FreeBSD, mt is used to control operations of the tape drive, such as seeking through files on a tape or writing tape control marks to the tape. For example, the first three files on a tape can be preserved by skipping past them before writing a new file:.

This utility supports many operations. Refer to mt 1 for details. To write a single file to tape using tar , specify the name of the tape device and the file to backup:. To backup a UFS file system, use dump. The FreeBSD Ports Collection provides many third-party utilities which can be used to schedule the creation of backups, simplify tape backup, and make backups easier and more convenient.

In addition to regular backups, it is recommended to perform the following steps as part of an emergency preparedness plan. Store this printout and a copy of the installation media in a secure location. Should an emergency restore be needed, boot into the installation media and select Live CD to access a rescue shell. This rescue mode can be used to view the current state of the system, and if needed, to reformat disks and restore data from backups.

Next, test the rescue shell and the backups. Make notes of the procedure.