CernVM-FS Parameters

Client parameters

Parameters recognized in configuration files under /etc/cvmfs:

Parameter

Meaning

CVMFS_ALIEN_CACHE

If set, use an alien cache at the given location

CVMFS_ALT_ROOT_PATH

If set to yes, use alternative root catalog path.
Only required for fixed catalogs (tag / hash) under the alternative path.

CVMFS_AUTO_UPDATE

If set to no, disables the automatic update of file catalogs.

CVMFS_AUTHZ_HELPER

Full path to an authz helper, overwrites the helper hint in the catalog.

CVMFS_AUTHZ_SEARCH_PATH

Full path to the directory that contains the authz helpers.

CVMFS_BACKOFF_INIT

Seconds for the maximum initial backoff when retrying to download data.

CVMFS_BACKOFF_MAX

Maximum backoff in seconds when retrying to download data.

CVMFS_CATALOG_WATERMARK

Try to release pinned catalogs when their number surpasses the given watermark.
Defaults to 1/4 CVMFS_NFILES; explicitly set by shrinkwrap.

CVMFS_CACHE_BASE

Location (directory) of the CernVM-FS cache.

CVMFS_CHECK_PERMISSIONS

If set to no, disable checking of file ownership and permissions (open all files).

CVMFS_CLAIM_OWNERSHIP

If set to yes, allows CernVM-FS to claim ownership of files and directories.

CVMFS_DEBUGLOG

If set, run CernVM-FS in debug mode and write a verbose log the the specified file.

CVMFS_DEFAULT_DOMAIN

The default domain will be automatically appended to repository names
when given without a domain.

CVMFS_DNS_MIN_TTL

Minimum effective TTL in seconds for DNS queries of proxy server names
(not Stratum 1s). Defaults to 1 minute.

CVMFS_DNS_MAX_TTL

Maximum effective TTL in seconds for DNS queries of proxy server names
(not Stratum 1s). Defaults to 1 day.

CVMFS_DNS_RETRIES

Number of retries when resolving proxy names

CVMFS_DNS_TIMEOUT

Timeout in seconds when resolving proxy names

CVMFS_DNS_ROAMING

If true, watch /etc/resolv.conf for nameserver changes

CVMFS_ENFORCE_ACLS

Enforce POSIX ACLs stored in the repository. Requires libfuse 3.

CVMFS_EXTERNAL_FALLBACK_PROXY

List of HTTP proxies similar to CVMFS_EXTERNAL_HTTP_PROXY.
The fallback proxies are added to the end of the normal proxies,
and disable DIRECT connections.

CVMFS_EXTERNAL_HTTP_PROXY

Chain of HTTP proxy groups to be used when CernVM-FS is accessing external data

CVMFS_EXTERNAL_TIMEOUT

Timeout in seconds for HTTP requests to an external-data server with a proxy server

CVMFS_EXTERNAL_TIMEOUT_DIRECT

Timeout in seconds for HTTP requests to an external-data server without a proxy server

CVMFS_EXTERNAL_URL

Semicolon-separated chain of webservers serving external data chunks.

CVMFS_FALLBACK_PROXY

List of HTTP proxies similar to CVMFS_HTTP_PROXY. The fallback proxies are
added to the end of the normal proxies, and disable DIRECT connections.

CVMFS_FOLLOW_REDIRECTS

When set to yes, follow up to 4 HTTP redirects in requests.

CVMFS_HIDE_MAGIC_XATTRS

If set to yes the client will not expose CernVM-FS specific extended attributes

CVMFS_HOST_RESET_AFTER

See CVMFS_PROXY_RESET_AFTER.

CVMFS_HTTP_PROXY

Chain of HTTP proxy groups used by CernVM-FS. Necessary.
Set to DIRECT if you don’t use proxies.

CVMFS_IGNORE_SIGNATURE

When set to yes, don’t verify CernVM-FS file catalog signatures.

CVMFS_INITIAL_GENERATION

Initial inode generation. Used for testing.

CVMFS_INSTRUMENT_FUSE

When set to true gather performance statistics about the FUSE callbacks.
The results are displayed with cvmfs_talk internal affairs.

CVMFS_NFS_INTERLEAVED_INODES

In NFS mode, use only inodes of the form \(an+b\), specified as “b%a”.

CVMFS_IPFAMILY_PREFER

Which IP protocol to prefer when connecting to proxies. Can be either 4 or 6.

CVMFS_KCACHE_TIMEOUT

Timeout for path names and file attributes in the kernel file system buffers.

CVMFS_KEYS_DIR

Directory containing *.pub files used as repository signing keys.
If set, this parameter has precedence over CVMFS_PUBLIC_KEY.

CVMFS_LOW_SPEED_LIMIT

Minimum transfer rate a server or proxy must provide.

CVMFS_MAX_EXTERNAL_SERVERS

Limit the number of (geo sorted) stratum 1 servers for external data
that are effectively used.

CVMFS_MAX_IPADDR_PER_PROXY

Limit the number of IP addresses a proxy names resolves into.
From all registered addresses, up to the limit are randomly selected.

CVMFS_MAX_RETRIES

Maximum number of retries for a given proxy/host combination.

CVMFS_MAX_SERVERS

Limit the number of (geo sorted) stratum 1 servers that are effectively used.

CVMFS_MAX_TTL

Maximum file catalog TTL in minutes. Can overwrite the TTL stored in the catalog.

CVMFS_MEMCACHE_SIZE

Size of the CernVM-FS meta-data memory cache in Megabyte.

CVMFS_MOUNT_RW

Mount CernVM-FS as a read/write file system. Write operations will fail
but this option can workaround faulty open() flags.

CVMFS_NFILES

Maximum number of open file descriptors that can be used by the CernVM-FS process.

CVMFS_NFS_SOURCE

If set to yes, act as a source for the NFS daemon (NFS export).

CVMFS_NFS_SHARED

If set a path, used to store the NFS maps in an SQlite database,
instead of the usual LevelDB storage in the cache directory.

CVMFS_PAC_URLS

Chain of URLs pointing to PAC files with HTTP proxy configuration information.

CVMFS_OOM_SCORE_ADJ

Set the Linux kernel’s out-of-memory killer priority
for the CernVM-FS client [-1000 - 1000].

CVMFS_PROXY_RESET_AFTER

Delay in seconds after which CernVM-FS will retry the primary proxy group
in case of a fail-over to another group.

CVMFS_PROXY_TEMPLATE

Overwrite the default proxy template in Geo-API calls. Only needed for debugging.

CVMFS_PUBLIC_KEY

Colon-separated list of repository signing keys.

CVMFS_QUOTA_LIMIT

Soft-limit of the cache in Megabyte.

CVMFS_RELOAD_SOCKETS

Directory of the sockets used by the CernVM-FS loader to trigger hotpatching/reloading.

CVMFS_REPOSITORIES

Comma-separated list of fully qualified repository names
to include in use of client utilities such as cvmfs_talk and cvmfs_config.
Does not limit which repositories may be mounted, unless CVMFS_STRICT_MOUNT is
set to yes.

CVMFS_REPOSITORY_DATE

A timestamp in ISO format (e.g. 2007-03-01T13:00:00Z).
Selects the repository state as of the given date.

CVMFS_REPOSITORY_TAG

Select a named repository snapshot that should be mounted instead of trunk.

CVMFS_CONFIG_REPO_REQUIRED

If set to yes, no repository can be mounted unless the config repository is available.

CVMFS_ROOT_HASH

Hash of the root file catalog, implies CVMFS_AUTO_UPDATE=no.

CVMFS_SEND_INFO_HEADER

If set to yes, include the cvmfs path of downloaded data in HTTP headers.

CVMFS_SERVER_CACHE_MODE

Enable special cache semantics for a client used as a publisher’s repository base line.

CVMFS_SERVER_URL

Semicolon-separated chain of Stratum~1 servers.

CVMFS_SHARED_CACHE

If set to no, makes a repository use an exclusive cache.

CVMFS_STRICT_MOUNT

If set to yes, mount only repositories that are listed in CVMFS_REPOSITORIES.

CVMFS_SUID

If set to yes, enable suid magic on the mounted repository. Requires mounting as root.

CVMFS_SYSLOG_FACILITY

If set to a number between 0 and 7, uses the corresponding
LOCAL$n$ facility for syslog messages.

CVMFS_SYSLOG_LEVEL

If set to 1 or 2, sets the syslog level for CernVM-FS messages to
LOG_DEBUG or LOG_INFO respectively.

CVMFS_SYSTEMD_NOKILL

If set to yes, modify the command line to @vmfs2 ... in order to
act as a systemd lowlevel storage manager.

CVMFS_TIMEOUT

Timeout in seconds for HTTP requests with a proxy server.

CVMFS_TIMEOUT_DIRECT

Timeout in seconds for HTTP requests without a proxy server.

CVMFS_TRACEFILE

If set, enables the tracer and trace file system calls to the given file.

CVMFS_USE_GEOAPI

Request order of Stratum 1 servers and fallback proxies via Geo-API.

CVMFS_USER

Sets the gid and uid mount options. Don’t touch or overwrite.

CVMFS_USYSLOG

All messages that normally are logged to syslog are re-directed to the given file.
This file can grow up to 500kB and there is one step of log rotation.
Required for $mu$CernVM.

CVMFS_WORKSPACE

Set the local directory for storing special files (defaults to the cache directory).

CVMFS_USE_SSL_SYSTEM_CA

When connecting to an HTTPS endpoints,
it will load the certificates provided by the system.

Server parameters

Parameter

Meaning

CVMFS_AUFS_WARNING

Set to false to silence AUFS kernel deadlock warning.

CVMFS_AUTO_GC

Enables the automatic garbage collection on publish and snapshot

CVMFS_AUTO_GC_TIMESPAN

Date-threshold for automatic garbage collection
(For example: 3 days ago, 1 week ago, …)

CVMFS_AUTO_GC_LAPSE

Frequency of auto garbage collection, only garbage collect if last GC is
before the given threshold (For example: 1 day ago)

CVMFS_AUTO_REPAIR_MOUNTPOINT

Set to true to enable automatic recovery from bogus server mount states.

CVMFS_AUTO_TAG

Creates a generic revision tag for each published revision (if set to true).

CVMFS_AUTO_TAG_TIMESPAN

Date-threshold for automatic tags, after which auto tags get removed
(For example: 4 days ago)

CVMFS_AUTOCATALOGS

Enable/disable automatic catalog management using autocatalogs.

CVMFS_AUTOCATALOGS_MAX_WEIGHT

Maximum number of entries in an autocatalog to be considered overflowed.
Default value: 100000
(see also CVMFS_AUTOCATALOGS)

CVMFS_AUTOCATALOGS_MIN_WEIGHT

Minimum number of entries in an autocatalog to be considered underflowed.
Default value: 1000
(see also CVMFS_AUTOCATALOGS)

CVMFS_AVG_CHUNK_SIZE

Desired Average size of a file chunk in bytes
(see also CVMFS_USE_FILE_CHUNKING)

CVMFS_CATALOG_ALT_PATHS

Enable/disable generation of catalog bootstrapping shortcuts during publishing.
(Useful when backend directory /data is not publicly accessible)

CVMFS_COMPRESSION_ALGORITHM

Compression algorithm to be used during publishing
(currently either ‘default’ or ‘none’)

CVMFS_CREATOR_VERSION

The CernVM-FS version that was used to create this repository
(do not change manually).

CVMFS_DONT_CHECK_OVERLAYFS_VERSION

Disable checking of OverlayFS version before usage.

CVMFS_ENFORCE_LIMITS

Set to true to cause exceeding *LIMIT variables to be fatal to a publish
instead of a warning

CVMFS_EXTENDED_GC_STATS

Set to true to keep track of the volume of garbage collected files (increases GC running time)

CVMFS_EXTERNAL_DATA

Set to true to mark repository to contain external data
that is served from an external HTTP server

CVMFS_FILE_MBYTE_LIMIT

Maximum number of megabytes for a published file, default value: 1024
(see also CVMFS_ENFORCE_LIMITS)

CVMFS_FORCE_REMOUNT_WARNING

Enable/disable warning through wall and grace period before forcefully
remounting a CernVM-FS repository on the release managere machine.

CVMFS_GARBAGE_COLLECTION

Enables repository garbage collection
(Stratum~0 only | if set to true)

CVMFS_GENERATE_LEGACY_BULK_CHUNKS

Deprecated, set to true to enable generation of whole-file objects for large files.

CVMFS_GC_DELETION_LOG

Log file path to track all garbage collected objects during sweeping
for bookkeeping or debugging

CVMFS_GEO_DB_FILE

Path to externally updated location of geolite2 city database, or ‘None’ for no database.

CVMFS_GEO_LICENSE_KEY

A license key for downloading the geolite2 city database from maxmind.

CVMFS_GID_MAP

Path of a file for the mapping of file owner group ids.

CVMFS_HASH_ALGORITHM

Define which secure hash algorithm should be used by CernVM-FS for CAS objects
(supported are: sha1, rmd160 and shake128)

CVMFS_IGNORE_SPECIAL_FILES

Set to true to skip special files during publish without aborting.

CVMFS_IGNORE_XDIR_HARDLINKS

Deprecated, defaults to true
hardlinks are found. Instead automatically break the hardlinks across directories.

CVMFS_INCLUDE_XATTRS

Set to true to process extended attributes

CVMFS_MAX_CHUNK_SIZE

Maximal size of a file chunk in bytes (see also CVMFS_USE_FILE_CHUNKING)

CVMFS_MAXIMAL_CONCURRENT_WRITES

Maximal number of concurrently processed files during publishing.

CVMFS_MIN_CHUNK_SIZE

Minimal size of a file chunk in bytes (see also CVMFS_USE_FILE_CHUNKING)

CVMFS_NESTED_KCATALOG_LIMIT

Maximum thousands of files allowed in nested catalogs, default 500
(see also CVMFS_ROOT_KCATALOG_LIMIT and CVMFS_ENFORCE_LIMITS)

CVMFS_NUM_UPLOAD_TASKS

Number of threads used to commit data to storage during publication.
Currently only used by the local backend.

CVMFS_NUM_WORKERS

Maximal number of concurrently downloaded files during a Stratum1 pull operation
(Stratum~1 only).

CVMFS_PUBLIC_KEY

Colon-separated path to the public key file(s) or directory(ies) of the repository to be replicated. (Stratum 1 only).

CVMFS_PRINT_STATISTICS

Set to true to show publisher statistics on the console

CVMFS_REPLICA_ACTIVE

Stratum1-only: Set to no to skip this repository when executing
cvmfs_server snapshot -a

CVMFS_REPOSITORY_NAME

The fully qualified name of the specific repository.

CVMFS_REPOSITORY_TYPE

Defines if the repository is a master copy (stratum0) or a replica (stratum1).

CVMFS_REPOSITORY_TTL

The frequency in seconds of client lookups for changes in the repository.
Defaults to 4 minutes.

CVMFS_ROOT_KCATALOG_LIMIT

Maximum thousands of files allowed in root catalogs, default 200
(see also CVMFS_NESTED_KCATALOG_LIMIT and CVMFS_ENFORCE_LIMITS

CVMFS_SNAPSHOT_GROUP

Group name for subset of repositories used with cvmfs_server snapshot -a -g.
Added with cvmfs_server add-replica -g.

CVMFS_SPOOL_DIR

Location of the upstream spooler scratch directories;
the read-only CernVM-FS moint point and copy-on-write storage reside here.

CVMFS_STATISTICS_DB

Set a custom path for the publisher statistics database

CVMFS_STATS_DB_DAYS_TO_KEEP

Sets the pruning interval for the publisher statistics database (365 by default)

CVMFS_STRATUM0

URL of the master copy (stratum0) of this specific repository.

CVMFS_STRATUM1

URL of the Stratum1 HTTP server for this specific repository.

CVMFS_SYNCFS_LEVEL

Controls how often sync will by called by cvmfs_server operations.
Possible levels are ‘none’, ‘default’, ‘cautious’.

CVMFS_UID_MAP

Path of a file for the mapping of file owner user ids.

CVMFS_UNION_DIR

Mount point of the union file system for copy-on-write semantics of CernVM-FS.
Here, changes to the repository are performed

CVMFS_UNION_FS_TYPE

Defines the union file system to be used for the repository.
(currently aufs and overlayfs are fully supported)

CVMFS_UPLOAD_STATS_DB

Publish repository statistics data file to the Stratum 0 /stats location

CVMFS_UPLOAD_STATS_PLOTS

Publish repository statistics plots and webpage to the Stratum 0 /stats location (requires ROOT)

CVMFS_UPSTREAM_STORAGE

Upstream spooler description defining the basic upstream storage type
and configuration (see below).

CVMFS_USE_FILE_CHUNKING

Allows backend to split big files into small chunks (true | false)

CVMFS_USER

The user name that owns and manipulates the files inside the repository.

CVMFS_VIRTUAL_DIR

Set to true to enable the hidden, virtual .cvmfs/snapshots directory
containing entry points to all named tags.

CVMFS_VOMS_AUTHZ

Membership requirement (e.g. VOMS authentication) to be added into the file catalogs

CVMFS_STATISTICS_DB

SQLite file path to store the statistics. Default is
/var/spool/cvmfs/<REPO_NAME>/stats.db .

CVMFS_PRINT_STATISTICS

Set to true to enable statistics printing to the standard output.

X509_CERT_BUNDLE

Bundle file with CA certificates for HTTPS connections (see Large-Scale Data CernVM-FS)

X509_CERT_DIR

Directory file with CA certificates for HTTPS connections,
defaults to /etc/grid-security/certificates (see Large-Scale Data CernVM-FS)

Format of CVMFS_UPSTREAM_STORAGE

The format of the CVMFS_UPSTREAM_STORAGE parameter depends on the storage backend. Note that this parameter is initialized by cvmfs_server mkfs resp. cvmfs_server add-replica. The internals of the parameter are only relevant if the configuration is maintained by a configuration management system.

For the local storage backend, the parameter specifies the storage directory (to be served by Apache) and a temporary directory in the form local,<path for temporary files>,<path to storage>, e.g.

CVMFS_UPSTREAM_STORAGE=local,/srv/cvmfs/sw.cvmfs.io/data/txn,/srv/cvmfs/sw.cvmfs.io

For the S3 backend, the parameter specifies a temporary directory and the location of the S3 config file in the form s3,<path for temporary files>,<repository entry URL on the S3 server>@<S3 config file>, e.g.

CVMFS_UPSTREAM_STORAGE=S3,/var/spool/cvmfs/sw.cvmfs.io/tmp,cvmfs/sw.cvmfs.io@/etc/cvmfs/s3.conf

The gateway backend can only be used on a remote publisher (not on a stratum 1). The parameter specifies a temporary directory and the endpoint of the gateway service, e.g.

CVMFS_UPSTREAM_STORAGE=gw,/var/spool/cvmfs/sw.cvmfs.io/tmp,http://cvmfs-gw.cvmfs.io:4929/api/v1

Tiered Cache Parameters

The following parameters are used to configure a tiered cache manager instance.

Parameter

Meaning

CVMFS_CACHE_$name_UPPER

Name of the upper layer cache instance

CVMFS_CACHE_$name_LOWER

Name of the lower layer cache instance

CVMFS_CACHE_LOWER_READONLY

Set to true to avoid populating the lower layer

External Cache Plugin Parameters

The following parameters are used to configure an external cache plugin as a cache manager instance.

Parameter

Meaning

CVMFS_CACHE_$name_CMDLINE

If the client should start the plugin, the executable and command line
parameters of the plugin, separated by comma.

CVMFS_CACHE_$name_LOCATOR

The address of the socket used for communication with the plugin.

In-memory Cache Plugin Parameters

The following parameters are interpreted from the configuration file provided to the in-memory cache plugin (see Section Example).

Parameter

Meaning

CVMFS_CACHE_PLUGIN_DEBUGLOG

If set, run CernVM-FS in debug mode and write a verbose log the the specified file.

CVMFS_CACHE_PLUGIN_LOCATOR

The address of the socket used for client communication

CVMFS_CACHE_PLUGIN_SIZE

The amount of RAM in megabyte used by the plugin for caching.