Backblaze B2

B2 is Backblaze's cloud storage system.

Lowest Cost Cloud Storage First 10 GB are free. Sign up today to begin using Backblaze B2. By pressing the button above you will create a Backblaze account and agree to our terms of service. Choose a number from below, or type in your own value snip XX / Backblaze B2 'b2' snip Storage b2 Account ID or Application Key ID account 123456789abc Application Key key abcdefabcdef Endpoint for the service - leave blank normally. Endpoint Remote config - remote account = 123456789abc key =. Server-side encryption protects your data by encrypting it before it is stored on disk by Backblaze B2 Cloud Storage. Files that are encrypted using server-side encryption (SSE) may be accessed using the same API calls as other B2 files (using either our B2 Native API or the S3 Compatible API). Add B2 as a new cloud storage destination. Enter the B2 Application Key ID and B2 Application Key. Enter B2 Bucket name identified above and select 'OK'. Select the files/folders to backup from your Windows Server to B2. Select 'Next' and watch the backup start.

Paths are specified as remote:bucket (or remote: for the lsdcommand.) You may put subdirectories in too, e.g. remote:bucket/path/to/dir.

Here is an example of making a b2 configuration. First run

This will guide you through an interactive setup process. To authenticateyou will either need your Account ID (a short hex number) and MasterApplication Key (a long hex number) OR an Application Key, which is therecommended method. See below for further details on generating and usingan Application Key.

This remote is called remote and can now be used like this

See all buckets

Create a new bucket

List the contents of a bucket

Sync /home/local/directory to the remote bucket, deleting anyexcess files in the bucket.

Application Keys

B2 supports multiple Application Keys for different access permissionto B2 Buckets.

You can use these with rclone too; you will need to use rclone version 1.43or later.

Follow Backblaze's docs to create an Application Key with the requiredpermission and add the applicationKeyId as the account and theApplication Key itself as the key.

Note that you must put the applicationKeyId as the account – youcan't use the master Account ID. If you try then B2 will return 401errors.

--fast-list

This remote supports --fast-list which allows you to use fewertransactions in exchange for more memory. See the rclonedocs for more details.

Modified time

The modified time is stored as metadata on the object asX-Bz-Info-src_last_modified_millis as milliseconds since 1970-01-01in the Backblaze standard. Other tools should be able to use this asa modified time.

Modified times are used in syncing and are fully supported. Note thatif a modification time needs to be updated on an object then it willcreate a new version of the object.

Restricted filename characters

In addition to the default restricted characters setthe following characters are also replaced:

Character	Value	Replacement
	0x5C	＼

Invalid UTF-8 bytes will also be replaced,as they can't be used in JSON strings.

Note that in 2020-05 Backblaze started allowing characters in filenames. Rclone hasn't changed its encoding as this could cause syncs tore-transfer files. If you want rclone not to replace then see the--b2-encoding flag below and remove the BackSlash from thestring. This can be set in the config.

SHA1 checksums

The SHA1 checksums of the files are checked on upload and download andwill be used in the syncing process.

Large files (bigger than the limit in --b2-upload-cutoff) which areuploaded in chunks will store their SHA1 on the object asX-Bz-Info-large_file_sha1 as recommended by Backblaze.

For a large file to be uploaded with an SHA1 checksum, the sourceneeds to support SHA1 checksums. The local disk supports SHA1checksums so large file transfers from local disk will have an SHA1.See the overview for exactly which remotessupport SHA1.

Sources which don't support SHA1, in particular crypt will uploadlarge files without SHA1 checksums. This may be fixed in the future(see #1767).

Files sizes below --b2-upload-cutoff will always have an SHA1regardless of the source.

Transfers

Backblaze recommends that you do lots of transfers simultaneously formaximum speed. In tests from my SSD equipped laptop the optimumsetting is about --transfers 32 though higher numbers may be usedfor a slight speed improvement. The optimum number for you may varydepending on your hardware, how big the files are, how much you wantto load your computer, etc. The default of --transfers 4 isdefinitely too low for Backblaze B2 though.

Note that uploading big files (bigger than 200 MB by default) will usea 96 MB RAM buffer by default. There can be at most --transfers ofthese in use at any moment, so this sets the upper limit on the memoryused.

Versions

When rclone uploads a new version of a file it creates a new versionof it.Likewise when you delete a file, the old version will be marked hiddenand still be available. Conversely, you may opt in to a 'hard delete'of files with the --b2-hard-delete flag which would permanently removethe file instead of hiding it.

Old versions of files, where available, are visible using the--b2-versions flag.

NB Note that --b2-versions does not work with crypt at themoment #1627. Using--backup-dir with rclone is the recommendedway of working around this.

If you wish to remove all the old versions then you can use therclone cleanup remote:bucket command which will delete all the oldversions of files, leaving the current ones intact. You can alsosupply a path and only old versions under that path will be deleted,e.g. rclone cleanup remote:bucket/path/to/stuff.

Note that cleanup will remove partially uploaded files from the bucketif they are more than a day old.

When you purge a bucket, the current and the old versions will bedeleted then the bucket will be deleted.

However delete will cause the current versions of the files tobecome hidden old versions.

Here is a session showing the listing and retrieval of an oldversion followed by a cleanup of the old versions.

Show current version and all the versions with --b2-versions flag.

Retrieve an old version

Clean up all the old versions and show that they've gone.

Data usage

It is useful to know how many requests are sent to the server in different scenarios.

All copy commands send the following 4 requests:

The b2_list_file_names request will be sent once for every 1k filesin the remote path, providing the checksum and modification time ofthe listed files. As of version 1.33 issue#818 causes extra requeststo be sent when using B2 with Crypt. When a copy operation does notrequire any files to be uploaded, no more requests will be sent.

Uploading files that do not require chunking, will send 2 requests perfile upload:

Uploading files requiring chunking, will send 2 requests (one each tostart and finish the upload) and another 2 requests for each chunk:

Versions

Versions can be viewed with the --b2-versions flag. When it is setrclone will show and act on older versions of files. For example

Listing without --b2-versions

And with

Showing that the current version is unchanged but older versions canbe seen. These have the UTC date that they were uploaded to theserver to the nearest millisecond appended to them.

Note that when using --b2-versions no file write operations arepermitted, so you can't upload files or delete them.

B2 and rclone link

Rclone supports generating file share links for private B2 buckets.They can either be for a file for example:

or if run on a directory you will get:

you can then use the authorization token (the part of the url from the?Authorization= on) on any file path under that directory. For example:

Standard Options

Here are the standard options specific to b2 (Backblaze B2).

--b2-account

Account ID or Application Key ID

• Config: account
• Env Var: RCLONE_B2_ACCOUNT
• Type: string
• Default: '

--b2-key

Application Key

• Config: key
• Env Var: RCLONE_B2_KEY
• Type: string
• Default: '

--b2-hard-delete

Permanently delete files on remote removal, otherwise hide files.

• Config: hard_delete
• Env Var: RCLONE_B2_HARD_DELETE
• Type: bool
• Default: false

Advanced Options

Backblaze B2 Cloud Storage Software

Here are the advanced options specific to b2 (Backblaze B2).

--b2-endpoint

Endpoint for the service.Leave blank normally.

• Config: endpoint
• Env Var: RCLONE_B2_ENDPOINT
• Type: string
• Default: '

--b2-test-mode

A flag string for X-Bz-Test-Mode header for debugging.

This is for debugging purposes only. Setting it to one of the stringsbelow will cause b2 to return specific errors:

• 'fail_some_uploads'
• 'expire_some_account_authorization_tokens'
• 'force_cap_exceeded'

These will be set in the 'X-Bz-Test-Mode' header which is documentedin the b2 integrations checklist.

• Config: test_mode
• Env Var: RCLONE_B2_TEST_MODE
• Type: string
• Default: '

--b2-versions

Include old versions in directory listings.Note that when using this no file write operations are permitted,so you can't upload files or delete them.

• Config: versions
• Env Var: RCLONE_B2_VERSIONS
• Type: bool
• Default: false

--b2-upload-cutoff

Cutoff for switching to chunked upload.

Files above this size will be uploaded in chunks of '--b2-chunk-size'.

This value should be set no larger than 4.657GiB ( 5GB).

• Config: upload_cutoff
• Env Var: RCLONE_B2_UPLOAD_CUTOFF
• Type: SizeSuffix
• Default: 200M

--b2-copy-cutoff

Cutoff for switching to multipart copy

Any files larger than this that need to be server-side copied will becopied in chunks of this size.

The minimum is 0 and the maximum is 4.6GB.

Blaze B2

• Config: copy_cutoff
• Env Var: RCLONE_B2_COPY_CUTOFF
• Type: SizeSuffix
• Default: 4G

--b2-chunk-size

Upload chunk size. Must fit in memory.

When uploading large files, chunk the file into this size. Note thatthese chunks are buffered in memory and there might a maximum of'--transfers' chunks in progress at once. 5,000,000 Bytes is theminimum size.

• Config: chunk_size
• Env Var: RCLONE_B2_CHUNK_SIZE
• Type: SizeSuffix
• Default: 96M

--b2-disable-checksum

Disable checksums for large (> upload cutoff) files

Normally rclone will calculate the SHA1 checksum of the input beforeuploading it so it can add it to metadata on the object. This is greatfor data integrity checking but can cause long delays for large filesto start uploading.

• Config: disable_checksum
• Env Var: RCLONE_B2_DISABLE_CHECKSUM
• Type: bool
• Default: false

--b2-download-url

Custom endpoint for downloads.

This is usually set to a Cloudflare CDN URL as Backblaze offersfree egress for data downloaded through the Cloudflare network.Rclone works with private buckets by sending an 'Authorization' header.If the custom endpoint rewrites the requests for authentication,e.g., in Cloudflare Workers, this header needs to be handled properly.Leave blank if you want to use the endpoint provided by Backblaze.

• Config: download_url
• Env Var: RCLONE_B2_DOWNLOAD_URL
• Type: string
• Default: '

--b2-download-auth-duration

Time before the authorization token will expire in s or suffix ms|s|m|h|d.

The duration before the download authorization token will expire.The minimum value is 1 second. The maximum value is one week.

• Config: download_auth_duration
• Env Var: RCLONE_B2_DOWNLOAD_AUTH_DURATION
• Type: Duration
• Default: 1w

--b2-memory-pool-flush-time

How often internal memory buffer pools will be flushed.Uploads which requires additional buffers (f.e multipart) will use memory pool for allocations.This option controls how often unused buffers will be removed from the pool.

• Config: memory_pool_flush_time
• Env Var: RCLONE_B2_MEMORY_POOL_FLUSH_TIME
• Type: Duration
• Default: 1m0s

--b2-memory-pool-use-mmap

Whether to use mmap buffers in internal memory pool.

• Config: memory_pool_use_mmap
• Env Var: RCLONE_B2_MEMORY_POOL_USE_MMAP
• Type: bool
• Default: false

--b2-encoding

This sets the encoding for the backend.

See: the encoding section in the overview for more info.

• Config: encoding
• Env Var: RCLONE_B2_ENCODING
• Type: MultiEncoder
• Default: Slash,BackSlash,Del,Ctl,InvalidUtf8,Dot

Limitations

rclone about is not supported by the B2 backend. Backends withoutthis capability cannot determine free space for an rclone mount oruse policy mfs (most free space) as a member of an rclone unionremote.

See List of backends that do not support rclone aboutSee rclone about