GlusterFS – Volume – zeige alle verfügbaren Optionen und deren Default Werte

System ist ein Debian Wheezy mit GlusterFS 3.6.1
Wer sein Volume Tunen / Optimieren möchte muss entsprechende Werte / Optionen setzen oder die Defaultwerte verändernt. Damit man überhaupt sieht welche Optionen möglich sind gibt es einen Befehl, der zudem auch eine kurze Erklärung der einzelnen Optionen anzeigt. Dieser lautet:

# gluster volume set help

Option: cluster.lookup-unhashed
Default Value: on
Description: This option if set to ON, does a lookup through all the sub-volumes, in case a lookup didn’t return any result from the hash subvolume. If set to OFF, it does not do a lookup on the remaining subvolumes.

Option: cluster.min-free-disk
Default Value: 10%
Description: Percentage/Size of disk space, after which the process starts balancing out the cluster, and logs will appear in log files

Option: cluster.min-free-inodes
Default Value: 5%
Description: after system has only N% of inodes, warnings starts to appear in log files

Option: cluster.rebalance-stats
Default Value: off
Description: This option if set to ON displays and logs the time taken for migration of each file, during the rebalance process. If set to OFF, the rebalance logs will only display the time spent in each directory.

Option: cluster.subvols-per-directory
Default Value: (null)
Description: Specifies the directory layout spread. Takes number of subvolumes as default value.

Option: cluster.readdir-optimize
Default Value: off
Description: This option if set to ON enables the optimization that allows DHT to requests non-first subvolumes to filter out directory entries.

Option: cluster.weighted-rebalance

Default Value: on
Description: When enabled, files will be allocated to bricks with a probability proportional to their size. Otherwise, all bricks will have the same probability (legacy behavior).

Option: cluster.entry-change-log
Default Value: on
Description: Entry fops like create/unlink will not perform pre/post fop changelog operations in afr transaction if this option is disabled

Option: cluster.read-subvolume
Default Value: (null)
Description: inode-read fops happen only on one of the bricks in replicate. Afr will prefer the one specified using this option if it is not stale. Option value must be one of the xlator names of the children. Ex: <volname>-client-0 till <volname>-client-<number-of-bricks – 1>

Option: cluster.read-subvolume-index
Default Value: -1
Description: inode-read fops happen only on one of the bricks in replicate. AFR will prefer the one specified using this option if it is not stale. allowed options include -1 till replica-count – 1

Option: cluster.read-hash-mode
Default Value: 1
Description: inode-read fops happen only on one of the bricks in replicate. AFR will prefer the one computed using the method specified using this option0 = first up server, 1 = hash by GFID of file (all clients use same subvolume), 2 = hash by GFID of file and client PID

Option: cluster.background-self-heal-count

Default Value: 16
Description: This specifies the number of self-heals that can be performed in background without blocking the fop

Option: cluster.metadata-self-heal
Default Value: on
Description: Using this option we can enable/disable metadata i.e. Permissions, ownerships, xattrs self-heal on the file/directory.

Option: cluster.data-self-heal
Default Value: on
Description: Using this option we can enable/disable data self-heal on the file. „open“ means data self-heal action will only be triggered by file open operations.

Option: cluster.entry-self-heal
Default Value: on
Description: Using this option we can enable/disable entry self-heal on the directory.

Option: cluster.self-heal-daemon
Default Value: on
Description: This option applies to only self-heal-daemon. Index directory crawl and automatic healing of files will not be performed if this option is turned off.

Option: cluster.self-heal-window-size
Default Value: 1
Description: Maximum number blocks per file for which self-heal process would be applied simultaneously.

Option: cluster.data-change-log
Default Value: on

his option is disabled

Option: cluster.metadata-change-log
Default Value: on
Description: Metadata fops like setattr/setxattr will not perform pre/post fop changelog operations in afr transaction if this option is disabled

Option: cluster.data-self-heal-algorithm
Default Value: (null)
Description: Select between „full“, „diff“. The „full“ algorithm copies the entire file from source to sink. The „diff“ algorithm copies to sink only those blocks whose checksums don’t match with those of source. If no option is configured the option is chosen dynamically as follows: If the file does not exist on one of the sinks or empty file exists or if the source file size is about the same as page size the entire file will be read and written i.e „full“ algo, otherwise „diff“ algo is chosen.

Option: cluster.eager-lock
Default Value: on
Description: Lock phase of a transaction has two sub-phases. First is an attempt to acquire locks in parallel by broadcasting non-blocking lock requests. If lock acquisition fails on any server, then the held locks are unlocked and revert to a blocking locked mode sequentially on one server after another. If this option is enabled the initial broadcasting lock request attempt to acquire lock on the entire file. If this fails, we revert back to the sequential „regional“ blocking lock as before. In the case where such an „eager“ lock is granted in the non-blocking phase, it gives rise to an opportunity for optimization. i.e, if the next write transaction on the same FD arrives before the unlock phase of the first transaction, it „takes over“ the full file lock. Similarly if yet another data transaction arrives before the unlock phase of the „optimized“ transaction, that in turn „takes over“ the lock as well. The actual unlock now happens at the end of the last „optimized“ transaction.

Option: cluster.quorum-type

Default Value: none
Description: If value is „fixed“ only allow writes if quorum-count bricks are present. If value is „auto“ only allow writes if more than half of bricks, or exactly half including the first, are present.

Option: cluster.quorum-count
Default Value: (null)
Description: If quorum-type is „fixed“ only allow writes if this many bricks or present. Other quorum types will OVERWRITE this value.

Option: cluster.choose-local
Default Value: true
Description: Choose a local subvolume (i.e. Brick) to read from if read-subvolume is not explicitly set.

Option: cluster.self-heal-readdir-size
Default Value: 1KB
Description: readdirp size for performing entry self-heal

Option: cluster.ensure-durability
Default Value: on
Description: Afr performs fsyncs for transactions if this option is on to make sure the changelogs/data is written to the disk

Option: cluster.stripe-block-size
Default Value: 128KB
Description: Size of the stripe unit that would be read from or written to the striped servers.

Option: cluster.stripe-coalesce
Default Value: true

Description: Enable/Disable coalesce mode to flatten striped files as stored on the server (i.e., eliminate holes caused by the traditional format).

Option: diagnostics.latency-measurement
Default Value: off
Description: If on stats related to the latency of each operation would be tracked inside GlusterFS data-structures.

Option: diagnostics.dump-fd-stats
Default Value: off
Description: If on stats related to file-operations would be tracked inside GlusterFS data-structures.

Option: diagnostics.brick-log-level
Default Value: INFO
Description: Changes the log-level of the bricks

Option: diagnostics.client-log-level
Default Value: INFO
Description: Changes the log-level of the clients

Option: diagnostics.brick-sys-log-level
Default Value: CRITICAL
Description: Gluster’s syslog log-level

Option: diagnostics.client-sys-log-level
Default Value: CRITICAL
Description: Gluster’s syslog log-level

Option: diagnostics.brick-logger
Default Value: (null)

Description: (null)

Option: diagnostics.client-logger
Default Value: (null)
Description: (null)

Option: diagnostics.brick-log-format
Default Value: (null)
Description: (null)

Option: diagnostics.client-log-format
Default Value: (null)
Description: (null)

Option: diagnostics.brick-log-buf-size
Default Value: 5
Description: (null)

Option: diagnostics.client-log-buf-size
Default Value: 5
Description: (null)

Option: diagnostics.brick-log-flush-timeout
Default Value: 120
Description: (null)

Option: diagnostics.client-log-flush-timeout
Default Value: 120
Description: (null)

Option: performance.cache-max-file-size
Default Value: 0
Description: Maximum file size which would be cached by the io-cache translator.

Option: performance.cache-min-file-size
Default Value: 0
Description: Minimum file size which would be cached by the io-cache translator.

Option: performance.cache-refresh-timeout
Default Value: 1
Description: The cached data for a file will be retained till ‚cache-refresh-timeout‘ seconds, after which data re-validation is performed.

Option: performance.cache-priority
Default Value:
Description: Assigns priority to filenames with specific patterns so that when a page needs to be ejected out of the cache, the page of a file whose priority is the lowest will be ejected earlier

Option: performance.cache-size
Default Value: 32MB
Description: Size of the read cache.

Option: performance.io-thread-count
Default Value: 16
Description: Number of threads in IO threads translator which perform concurrent IO operations

Option: performance.high-prio-threads
Default Value: 16

Default Value: 16
Description: Max number of threads in IO threads translator which perform high priority IO operations at a given time

Option: performance.normal-prio-threads
Default Value: 16
Description: Max number of threads in IO threads translator which perform normal priority IO operations at a given time

Option: performance.low-prio-threads
Default Value: 16
Description: Max number of threads in IO threads translator which perform low priority IO operations at a given time

Option: performance.least-prio-threads
Default Value: 1
Description: Max number of threads in IO threads translator which perform least priority IO operations at a given time

Option: performance.enable-least-priority
Default Value: on
Description: Enable/Disable least priority

Option: performance.least-rate-limit
Default Value: 0
Description: Max number of least priority operations to handle per-second

Option: performance.cache-size
Default Value: 128MB
Description: Size of the read cache.

Option: performance.flush-behind
Default Value: on
Description: If this option is set ON, instructs write-behind translator to perform flush in background, by returning success (or any errors, if any of previous writes were failed) to application even before flush FOP is sent to backend filesystem.

Option: performance.nfs.flush-behind
Default Value: on
Description: If this option is set ON, instructs write-behind translator to perform flush in background, by returning success (or any errors, if any of previous writes were failed) to application even before flush FOP is sent to backend filesystem.

Option: performance.write-behind-window-size
Default Value: 1MB
Description: Size of the write-behind buffer for a single file (inode).

Option: performance.nfs.write-behind-window-size
Default Value: 1MB

Default Value: 1MB
Description: Size of the write-behind buffer for a single file (inode).

Option: performance.nfs.write-behind-window-size
Default Value: 1MB
Description: Size of the write-behind buffer for a single file (inode).

Option: performance.strict-o-direct
Default Value: off
Description: This option when set to off, ignores the O_DIRECT flag.

Option: performance.nfs.strict-o-direct
Default Value: off
Description: This option when set to off, ignores the O_DIRECT flag.

Option: performance.strict-write-ordering
Default Value: off
Description: Do not let later writes overtake earlier writes even if they do not overlap

Option: performance.nfs.strict-write-ordering
Default Value: off
Description: Do not let later writes overtake earlier writes even if they do not overlap

Option: performance.lazy-open
Default Value: yes
Description: Perform open in the backend only when a necessary FOP arrives (e.g writev on the FD, unlink of the file). When option is disabled, perform backend open right after unwinding open().

Option: performance.read-after-open
Default Value: no
Description: read is sent only after actual open happens and real fd is obtained, instead of doing on anonymous fd (similar to write)

Option: performance.read-ahead-page-count
Default Value: 4
Description: Number of pages that will be pre-fetched

Option: performance.md-cache-timeout
Default Value: 1
Description: Time period after which cache has to be refreshed

Option: features.encryption
Default Value: off
Description: enable/disable client-side encryption for the volume.

Option: encryption.master-key
Default Value: (null)

Default Value: (null)
Description: Pathname of regular file which contains master volume key

Option: encryption.data-key-size
Default Value: 256
Description: Data key size (bits)

Option: encryption.block-size
Default Value: 4096
Description: Atom size (bits)

Option: network.frame-timeout
Default Value: 1800
Description: Time frame after which the (file) operation would be declared as dead, if the server does not respond for a particular (file) operation.

Option: network.ping-timeout
Default Value: 42
Description: Time duration for which the client waits to check if the server is responsive.

Option: network.tcp-window-size
Default Value: (null)
Description: Specifies the window size for tcp socket.

Option: features.lock-heal
Default Value: off
Description: When the connection to client is lost, server cleans up all the locks held by the client. After the connection is restored, the client reacquires (heals) the fcntl locks released by the server.

Option: features.grace-timeout
Default Value: 10
Description: Specifies the duration for the lock state to be maintained on the client after a network disconnection. Range 10-1800 seconds.

Option: network.remote-dio
Default Value: disable
Description: If enabled, in open() and creat() calls, O_DIRECT flag will be filtered at the client protocol level so server will still continue to cache the file. This works similar to NFS’s behavior of O_DIRECT

Option: network.tcp-window-size
Default Value: (null)
Description: Specifies the window size for tcp socket.

Option: network.inode-lru-limit
Default Value: 16384
Description: Specifies the maximum megabytes of memory to be used in the inode cache.

Option: auth.allow
Default Value: (null)
Description: Allow a comma separated list of addresses and/or hostnames to connect to the server. Option auth.reject overrides this option. By default, all connections are allowed.

Option: auth.reject
Default Value: (null)
Description: Reject a comma separated list of addresses and/or hostnames to connect to the server. This option overrides the auth.allow option. By default, all connections are allowed.

Option: server.root-squash
Default Value: off
Description: Map requests from uid/gid 0 to the anonymous uid/gid. Note that this does not apply to any other uids or gids that might be equally sensitive, such as user bin or group staff.

Option: server.anonuid
Default Value: 65534
Description: value of the uid used for the anonymous user/nfsnobody when root-squash is enabled.

Option: server.anongid
Default Value: 65534
Description: value of the gid used for the anonymous user/nfsnobody when root-squash is enabled.

Option: server.statedump-path
Default Value: /var/run/gluster
Description: Specifies directory in which gluster should save its statedumps. By default it is the /tmp directory

Option: server.outstanding-rpc-limit
Default Value: 64
Description: Parameter to throttle the number of incoming RPC requests from a client. 0 means no limit (can potentially run out of memory)

Option: server.manage-gids
Default Value: off
Description: Resolve groups on the server-side.

Option: server.gid-timeout
Default Value: 2
Description: Timeout in seconds for the cached groups to expire.

Option: performance.write-behind
Default Value: on
Description: enable/disable write-behind translator in the volume.

Option: performance.read-ahead
Default Value: on
Description: enable/disable read-ahead translator in the volume.

Option: performance.readdir-ahead
Default Value: off
Description: enable/disable readdir-ahead translator in the volume.

Option: performance.io-cache
Default Value: on
Description: enable/disable io-cache translator in the volume.

Option: performance.quick-read
Default Value: on
Description: enable/disable quick-read translator in the volume.

Option: performance.open-behind
Default Value: on
Description: enable/disable open-behind translator in the volume.

Option: performance.stat-prefetch
Default Value: on
Description: enable/disable meta-data caching translator in the volume.

Option: performance.client-io-threads
Default Value: off
Description: enable/disable io-threads translator in the client graph of volume.

Option: performance.nfs.write-behind
Default Value: on
Description: enable/disable write-behind translator in the volume

Option: performance.force-readdirp
Default Value: true
Description: Convert all readdir requests to readdirplus to collect stat info on each entry.

Option: features.file-snapshot
Default Value: off
Description: enable/disable file-snapshot feature in the volume.

Option: features.uss
Default Value: off
Description: Enable/Disable User Servicable Snapshots on the volume.

Option: features.snapshot-directory
Default Value: .snaps
Description: Entry point directory for entering snapshot world

Option: network.compression
Default Value: off
Description: enable/disable network compression translator

Option: network.compression.window-size
Default Value: -15
Description: Size of the zlib history buffer.

Option: network.compression.mem-level
Default Value: 8
Description: Memory allocated for internal compression state. 1 uses minimum memory but is slow and reduces compression ratio; memLevel=9 uses maximum memory for optimal speed. The default value is 8.

Option: network.compression.min-size
Default Value: 0
Description: Data is compressed only when its size exceeds this.

Option: network.compression.compression-level
Default Value: -1
Description: Compression levels
0 : no compression, 1 : best speed,
9 : best compression, -1 : default compression

Option: features.quota-deem-statfs
Default Value: off
Description: If set to on, it takes quota limits intoconsideration while estimating fs size. (df command) (Default is off).

Option: nfs.enable-ino32
Default Value: no
Description: For nfs clients or apps that do not support 64-bit inode numbers, use this option to make NFS return 32-bit inode numbers instead. Disabled by default, so NFS returns 64-bit inode numbers.

Option: nfs.mem-factor
Default Value: 15
Description: Use this option to make NFS be faster on systems by using more memory. This option specifies a multiple that determines the total amount of memory used. Default value is 15. Increase to use more memory in order to improve performance for certain use cases.Please consult gluster-users list before using this option.

Option: nfs.export-dirs
Default Value: on
Description: By default, all subvolumes of nfs are exported as individual exports. There are cases where a subdirectory or subdirectories in the volume need to be exported separately. Enabling this option allows any directory on a volumes to be exported separately.Directory exports are enabled by default.

Option: nfs.export-volumes
Default Value: on
Description: Enable or disable exporting whole volumes, instead if used in conjunction with nfs3.export-dir, can allow setting up only subdirectories as exports. On by default.

Option: nfs.addr-namelookup
Default Value: off

Description: Users have the option of turning on name lookup for incoming client connections using this option. Use this option to turn on name lookups during address-based authentication. Turning this on will enable you to use hostnames in nfs.rpc-auth-* filters. In some setups, the name server can take too long to reply to DNS queries resulting in timeouts of mount requests. By default, name lookup is off

Option: nfs.dynamic-volumes
Default Value: off
Description: Internal option set to tell gnfs to use a different scheme for encoding file handles when DVM is being used.

Option: nfs.register-with-portmap
Default Value: on
Description: For systems that need to run multiple nfs servers, only one registration is possible with portmap service. Use this option to turn off portmap registration for Gluster NFS. On by default

Option: nfs.outstanding-rpc-limit
Default Value: 16
Description: Parameter to throttle the number of incoming RPC requests from a client. 0 means no limit (can potentially run out of memory)

Option: nfs.port
Default Value: 2049
Description: Use this option on systems that need Gluster NFS to be associated with a non-default port number.

Option: nfs.rpc-auth-unix
Default Value: on
Description: Disable or enable the AUTH_UNIX authentication type for a particular exported volume overriding defaults and general setting for AUTH_UNIX scheme. Must always be enabled for better interoperability. However, can be disabled if needed. Enabled by default.

Option: nfs.rpc-auth-null
Default Value: on
Description: Disable or enable the AUTH_NULL authentication type for a particular exported volume overriding defaults and general setting for AUTH_NULL. Must always be enabled. This option is here only to avoid unrecognized option warnings.

Option: nfs.rpc-auth-allow
Default Value: all
Description: Allow a comma separated list of addresses and/or hostnames to connect to the server. By default, all connections are allowed. This allows users to define a rule for a specific exported volume.

Option: nfs.rpc-auth-reject
Default Value: none
Description: Reject a comma separated list of addresses and/or hostnames from connecting to the server. By default, all connections are allowed. This allows users to define a rule for a specific exported volume.

Option: nfs.ports-insecure
Default Value: off

Description: Allow client connections from unprivileged ports. By default only privileged ports are allowed. Use this option to enable or disable insecure ports for a specific subvolume and to override the global setting set by the previous option.

Option: nfs.transport-type
Default Value: tcp
Description: Specifies the nfs transport type. Valid transport types are ‚tcp‘ and ‚rdma‘.

Option: nfs.trusted-sync
Default Value: off
Description: All writes and COMMIT requests are treated as async. This implies that no write requests are guaranteed to be on server disks when the write reply is received at the NFS client. Trusted sync includes trusted-write behaviour. Off by default.

Option: nfs.trusted-write
Default Value: off
Description: On an UNSTABLE write from client, return STABLE flag to force client to not send a COMMIT request. In some environments, combined with a replicated GlusterFS setup, this option can improve write performance. This flag allows user to trust Gluster replication logic to sync data to the disks and recover when required. COMMIT requests if received will be handled in a default manner by fsyncing. STABLE writes are still handled in a sync manner. Off by default.

Option: nfs.volume-access
Default Value: read-write
Description: Type of access desired for this subvolume: read-only, read-write(default)

Option: nfs.export-dir
Default Value:
Description: By default, all subvolumes of nfs are exported as individual exports. There are cases where a subdirectory or subdirectories in the volume need to be exported separately. This option can also be used in conjunction with nfs3.export-volumes option to restrict exports only to the subdirectories specified through this option. Must be an absolute path. Along with path allowed list of IPs/hostname can be associated with each subdirectory. If provided connection will allowed only from these IPs. By default connections from all IPs are allowed. Format: <dir>[(hostspec[|hostspec|…])][,…]. Where hostspec can be an IP address, hostname or an IP range in CIDR notation. e.g. /foo(192.168.1.0/24|host1|10.1.1.8),/host2. NOTE: Care must be taken while configuring this option as invalid entries and/or unreachable DNS servers can introduce unwanted delay in all the mount calls.

Option: nfs.disable
Default Value: false
Description: This option is used to start or stop the NFS server for individual volumes.

Option: nfs.nlm
Default Value: on
Description: This option, if set to ‚off‘, disables NLM server by not registering the service with the portmapper. Set it to ‚on‘ to re-enable it. Default value: ‚on‘

Option: nfs.acl
Default Value: on

Description: This option is used to control ACL support for NFS.

Option: nfs.mount-udp
Default Value: off
Description: set the option to ‚on‘ to enable mountd on UDP. Required for some Solaris and AIX NFS clients. The need for enabling this option often depends on the usage of NLM.

Option: nfs.mount-rmtab
Default Value: /var/lib/glusterd/nfs/rmtab
Description: Set the location of the cache file that is used to list all the NFS-clients that have connected through the MOUNT protocol. If this is on shared storage, all GlusterFS servers will update and output (with ’showmount‘) the same list.

Option: nfs.drc
Default Value: off
Description: Enable Duplicate Request Cache in gNFS server to improve correctness of non-idempotent operations like write, delete, link, et al

Option: nfs.drc-size
Default Value: 0x20000
Description: Sets the number of non-idempotent requests to cache in drc

Option: nfs.read-size
Default Value: (1 * 1048576ULL)
Description: Size in which the client should issue read requests to the Gluster NFSv3 server. Must be a multiple of 4KB (4096). Min and Max supported values are 4KB (4096) and 1MB (1048576) respectively. If the specified value is within the supported range but not a multiple of 4096, it is rounded up to the nearest multiple of 4096.

Option: nfs.write-size
Default Value: (1 * 1048576ULL)
Description: Size in which the client should issue write requests to the Gluster NFSv3 server. Must be a multiple of 1KB (1024). Min and Max supported values are 4KB (4096) and 1MB(1048576) respectively. If the specified value is within the supported range but not a multiple of 4096, it is rounded up to the nearest multiple of 4096.

Option: nfs.readdir-size
Default Value: (1 * 1048576ULL)
Description: Size in which the client should issue directory reading requests to the Gluster NFSv3 server. Must be a multiple of 1KB (1024). Min and Max supported values are 4KB (4096) and 1MB (1048576) respectively.If the specified value is within the supported range but not a multiple of 4096, it is rounded up to the nearest multiple of 4096.

Option: storage.linux-aio
Default Value: off
Description: Support for native Linux AIO

Option: storage.batch-fsync-mode
Default Value: reverse-fsync
Description: Possible values:
– syncfs: Perform one syncfs() on behalf oa batchof fsyncs.

– syncfs-single-fsync: Perform one syncfs() on behalf of a batch of fsyncs and one fsync() per batch.
– syncfs-reverse-fsync: Preform one syncfs() on behalf of a batch of fsyncs and fsync() each file in the batch in reverse order.
in reverse order.
– reverse-fsync: Perform fsync() of each file in the batch in reverse order.

Option: storage.batch-fsync-delay-usec
Default Value: 0
Description: Num of usecs to wait for aggregating fsync requests

Option: storage.owner-uid
Default Value: -1
Description: Support for setting uid of brick’s owner

Option: storage.owner-gid
Default Value: -1
Description: Support for setting gid of brick’s owner

Option: storage.node-uuid-pathinfo
Default Value: off
Description: return glusterd’s node-uuid in pathinfo xattr string instead of hostname

Option: storage.health-check-interval
Default Value: 30
Description: Interval in seconds for a filesystem health check, set to 0 to disable

Option: storage.build-pgfid
Default Value: off
Description: Enable placeholders for gfid to path conversion

Option: storage.bd-aio
Default Value: off
Description: Support for native Linux AIO

Option: cluster.server-quorum-type
Default Value: (null)
Description: This feature is on the server-side i.e. in glusterd. Whenever the glusterd on a machine observes that the quorum is not met, it brings down the bricks to prevent data split-brains. When the network connections are brought back up and the quorum is restored the bricks in the volume are brought back up.

Option: cluster.server-quorum-ratio
Default Value: (null)
Description: Sets the quorum percentage for the trusted storage pool.

Option: changelog.changelog-barrier-timeout
Default Value: 120
Description: After ‚timeout‘ seconds since the time ‚barrier‘ option was set to „on“, unlink/rmdir/rename operations are no longer blocked and previously blocked fops are allowed to go through

Option: features.barrier
Default Value: off
Description: When „on“, blocks acknowledgements to application for file operations such as rmdir, rename, unlink, removexattr, fremovexattr, truncate, ftruncate, write (with O_SYNC), fsync. It is turned „off“ by default.

Option: features.barrier-timeout
Default Value: 120
Description: After ‚timeout‘ seconds since the time ‚barrier‘ option was set to „on“, acknowledgements to file operations are no longer blocked and previously blocked acknowledgements are sent to the application

[End]

Mit folgendem Befehl kann man sehen welche Optionen gesetzt sind:

# gluster volume info vol2

Volume Name: vol2
Type: Distribute
Volume ID: 877d701a-4d45-44cf-8a03-e91cd12b706b
Status: Started
Number of Bricks: 2
Transport-type: tcp
Bricks:
Brick1: clusternode01:/media/node01/vol2
Brick2: clusternode02:/media/node02/vol2
Options Reconfigured:
cluster.min-free-disk: 100MB

Hier zu sehen unter Options Reconfigured: cluster.min-free-disk mit 100MB. Wie man eine Option setzt ist hier als Beispiel zu sehen: Set Min-Free-Disk