Project: JuiceFS (Runtime / Cloud Native Storage)
File: standalone.md

sidebar_position: 2 paginationnext: getting-started/fordistributed description: Learn how to use JuiceFS in standalone mode, combining object storage and databases for efficient file system management. The JuiceFS file system is driven by both and . In addition to object storage, it also supports using local disks, WebDAV, and HDFS as underlying storage options. Therefore, you can create a standalone file system using local disks and SQLite database to get a quick overview of how JuiceFS works. For Linux distributions and macOS users, the JuiceFS client can be quickly installed using a one-click installation script: ```shell curl -sSL https://d.juicefs.com/install | sh - ``` For other operating systems and installation methods, please refer to . Once installed successfully, executing the `juicefs` command in the terminal will return a help message regardless of the operating system. The JuiceFS client provides a command to create a file system as follows: ```shell juicefs format [command options] META-URL NAME ``` To format a file system, three types of information are required: [command options]: Sets up the storage medium for the file system; local disk will be used by default, and the default path is `"$HOME/.juicefs/local"`, `"/var/jfs"` or `"C:/jfs/local"`. META-URL: Sets up the metadata engine, typically a URL or the file path of a database. NAME: The name of the file system. :::tip JuiceFS supports a wide range of storage media and metadata storage engines. See and . ::: As an example on a Linux system, the following command creates a file system named `myjfs`: ```shell juicefs format sqlite3://myjfs.db myjfs ``` Upon completion, an output similar to the following will be returned: ```shell {1,4} 2021/12/14 18:26:37.666618 juicefs[40362] <INFO>: Meta address: sqlite3://myjfs.db [xorm] [info] 2021/12/14 18:26:37.667504 PING DATABASE sqlite3 2021/12/14 18:26:37.674147 juicefs[40362] <WARNING>: The latency to database is too high: 7.257333ms 2021/12/14 18:26:37.675713 juicefs[40362] <INFO>: Data use file:///Users/herald/.juicefs/local/myjfs/ 2021/12/14 18:26:37.689683 juicefs[40362] <INFO>: Volume is formatted as {Name:myjfs UUID:d5bdf7ea-472c-4640-98a6-6f56aea13982 Storage:file Bucket:/Users/herald/.juicefs/local/ AccessKey: SecretKey: BlockSize:4096 Compression:none Shards:0 Partitions:0 Capacity:0 Inodes:0 EncryptKey:} ``` As you can see from the output, the file system uses SQLite as the metadata storage engine. The database file is located in the current directory with the file name `myjfs.db`, which creates a table to store all the metadata of the file system `myjfs`. Since no storage-related options are specified in this example, the local disk is used as the storage medium by default. According to the output, the file system storage path is

The JuiceFS client provides a command to mount file systems in the following format: ```shell juicefs mount [command options] META-URL MOUNTPOINT ``` Similar to the command of creating a file system, the following information is also required to mount a file system: `[command options]`: Specifies file system-related options. For example, `-d` enables background mounts. `META-URL`: Sets up the metadata storage, typically a URL or file path of a database. `MOUNTPOINT`: Specifies a mount point of the file system. :::tip The mount point (`MOUNTPOINT`) on Windows systems should use a disk letter that is not yet occupied, such as `Z:` or `Y:`. ::: :::note As SQLite is a single-file database, please pay attention to the path of the database file when mounting it. JuiceFS supports both relative and absolute paths. ::: The following command mounts the `myjfs` file system to the `~/jfs` folder: ```shell juicefs mount sqlite3://myjfs.db ~/jfs ``` The client mounts the file system in the foreground by default. As you can see in the above image, the program keeps running in the current terminal. To unmount the file system, press <kbd>Ctrl</kbd> + <kbd>C</kbd> or close the terminal window. To keep the file system mounted in the background, specify the `-d` or `--background` option when mounting. This allows you to mount the file system in the daemon: ```shell juicefs mount sqlite3://myjfs.db ~/jfs -d ``` Next, any files stored in the mount point `~/jfs` will be split into specific blocks according to and stored in the `$HOME/.juicefs/local/myjfs` directory; the corresponding metadata will be stored in the `myjfs.db` database. In the end, the mount point `~/jfs` can be unmounted by executing the following command: ```shell juicefs umount ~/jfs ``` The above exercise only helps you to have a quick experience with JuiceFS locally and gives you a basic overview of how JuiceFS works. For a more practical example, consider using SQLite to store metadata as demonstrated, but replace the local storage with "object storage." Object Storage is a web storage service based on the HTTP protocol that offers simple APIs for access. It has a flat structure and is easy to scale and cost-effective, particularly suitable for storing large amounts of unstructured data. Almost all mainstream cloud computing platforms provide object storage services, such as Amazon S3, Alibaba Cloud OSS, and Backblaze B2. JuiceFS supports almost all object storage services, see . In general, only two steps are required to create an object storage: Create a Bucket and get the Endpoint

Create the Access Key ID and Access Key Secret, which serve as the access keys for the Object Storage API. Taking AWS S3 as an example, the created resources would look like the following: Bucket Endpoint: `https://myjfs.s3.us-west-1.amazonaws.com` Access Key ID: `ABCDEFGHIJKLMNopqXYZ` Access Key Secret: `ZYXwvutsrqpoNMLkJiHgfeDCBA` :::note The process of creating an object storage may vary slightly from platform to platform, so it is recommended to check the help manual of the corresponding cloud platform. In addition, some platforms may provide different Endpoint addresses for internal and external networks. Please choose the external network access for your application. This document illustrates accessing object storage from a local environment. ::: To create a JuiceFS file system using SQLite and Amazon S3 object storage: :::note If the `myjfs.db` file already exists, delete it first and then execute the following command. ::: ```shell juicefs format --storage s3 \ --bucket https://myjfs.s3.us-west-1.amazonaws.com \ --access-key ABCDEFGHIJKLMNopqXYZ \ --secret-key ZYXwvutsrqpoNMLkJiHgfeDCBA \ sqlite3://myjfs.db myjfs ``` The command above creates a file system using the same database name and file system name with the object storage options provided. `--storage`: Specifies the storage type, such ase `oss` and `s3`. `--bucket`: Specifies the Endpoint address of the object storage. `--access-key`: Specifies the Object Storage Access Key ID. `--secret-key`: Specifies the Object Storage Access Key Secret. Once created, you can mount the file system: ```shell juicefs mount sqlite3://myjfs.db ~/jfs ``` The mount command is exactly the same as using the local storage because JuiceFS has already written the metadata of the object storage to the `myjfs.db` database, so there is no need to provide it again when mounting. Compared with using local disks, the combination of SQLite and object storage is more practical. From an application perspective, this approach is equivalent to plugging an object storage with almost unlimited capacity into your local computer, allowing you to use cloud storage as a local disk. Further, all the data of the file system is stored in the cloud-based object storage, so the `myjfs.db` database can be copied to other computers where JuiceFS clients are installed for mounting, reading, and writing. That is, any computer that can read the metadata database can mount and read/write the file system. Obviously, it is difficult for a single file database like SQLite to be accessed by multiple computers at the same time. If SQLite is replaced by databases like Redis, PostgreSQL, and MySQL, which can be accessed by multiple computers at the same time through the network, it is possible to achieve distributed reads and writes on the JuiceFS file system.