layout: manual Content-Style: 'text/css' title: _MP(PMEMPOOL_FEATURE_QUERY, 3) collection: libpmempool header: PMDK date: pmempool API version 1.3 ...

comment: <> (pmempool_feature_query.3 -- man page for toggle and query pool set features)

NAME
SYNOPSIS
DESCRIPTION
COMPATIBILITY
DISCLAIMER
RETURN VALUE
SEE ALSO

NAME

_UW(pmempool_feature_query), _UW(pmempool_feature_enable), _UW(pmempool_feature_disable) - toggle or query pool set features

SYNOPSIS

#include <libpmempool.h>

_UWFUNCR1(int, pmempool_feature_query, *path, =q=enum pmempool_feature feature, unsigned flags=e=)

_UWFUNCR1(int, pmempool_feature_enable, *path, =q=enum pmempool_feature feature, unsigned flags=e=)

_UWFUNCR1(int, pmempool_feature_disable, *path, =q=enum pmempool_feature feature, unsigned flags=e=)

_UNICODE()

DESCRIPTION

The feature argument accepts following values:

• PMEMPOOL_FEAT_SINGLEHDR - only the first part in each replica contains the pool part internal metadata. This value can be used only with pmempool_feature_query(). It can not be enabled or disabled. For details see poolset(5).

• PMEMPOOL_FEAT_CKSUM_2K - only the first 2KiB of pool part internal metadata is checksummed. Other features may depend on this one to store additional metadata in otherwise unused second 2KiB part of a header. When PMEMPOOL_FEAT_CKSUM_2K is disabled whole 4KiB is checksummed.

• PMEMPOOL_FEAT_SHUTDOWN_STATE - enables additional check performed during pool open which verifies pool consistency in the presence of dirty shutdown. PMEMPOOL_FEAT_CKSUM_2K has to be enabled prior to PMEMPOOL_FEAT_SHUTDOWN_STATE otherwise enabling PMEMPOOL_FEAT_SHUTDOWN_STATE will fail.

• PMEMPOOL_FEAT_CHECK_BAD_BLOCKS - enables checking bad blocks performed during opening a pool and fixing bad blocks performed by pmempool-sync during syncing a pool. For details see pmempool-feature(1).

The _UW(pmempool_feature_query) function checks state of feature in the pool set pointed by path.

The _UW(pmempool_feature_enable) function enables feature in the pool set pointed by path.

The _UW(pmempool_feature_disable) function disables feature in the pool set pointed by path.

COMPATIBILITY

Poolsets with features not defined in this document (e.g. enabled by the newer software version) are not supported.

DISCLAIMER

_UW(pmempool_feature_query), _UW(pmempool_feature_enable) and _UW(pmempool_feature_disable) are not fail safe.

RETURN VALUE

On success, _UW(pmempool_feature_query) returns 0 if feature is disabled or 1 if it is enabled. On error, it returns -1 and sets errno accordingly.

On success, _UW(pmempool_feature_enable) returns 0. On error, it returns -1 and sets errno accordingly.

On success, _UW(pmempool_feature_disable) returns 0. On error, it returns -1 and sets errno accordingly.

If path points poolset with remote replica errno is set to EINVAL and function returns -1.

If non zero flags are provided errno is set to EINVAL and function returns -1.

SEE ALSO

poolset(5) and http://pmem.io