pmempool-feature - toggle or query pool set features
-
$ pmempool feature (-e|-d|-q feature-name) [options] <file>
The pmempool feature command enables / disables or queries pool set
features.
Available pool feature-names are:
- •
- SINGLEHDR - only the first part in each replica contains the pool
part internal metadata. This value can be used only with -q. It can
not be enabled or disabled. For details see poolset(5).
- •
- CHECKSUM_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
CHECKSUM_2K is disabled whole 4KiB is checksummed.
- •
- SHUTDOWN_STATE - enables additional check performed during pool
open which verifies pool consistency in the presence of dirty shutdown.
CHECKSUM_2K has to be enabled prior to SHUTDOWN_STATE
otherwise enabling SHUTDOWN_STATE will fail.
- •
- CHECK_BAD_BLOCKS - enables checking bad blocks performed during
opening a pool and fixing bad blocks performed by pmempool-sync during
syncing a pool. Currently (Linux kernel v4.19, libndctl v62) checking and
fixing bad blocks require read access to the following resource files
(containing physical addresses) of NVDIMM devices which only root can read
by default:
-
/sys/bus/nd/devices/ndbus*/region*/resource
/sys/bus/nd/devices/ndbus*/region*/dax*/resource
/sys/bus/nd/devices/ndbus*/region*/pfn*/resource
/sys/bus/nd/devices/ndbus*/region*/namespace*/resource
It is possible to use poolset as file argument. But
poolsets with remote replicas are not supported.
-h, --help
Print help message.
-v, --verbose
Increase verbosity level.
-e, --enable feature-name
Enable feature for pool set.
-d, --disable feature-name
Disable feature for pool set.
-q, --query feature-name
Print feature status.
Poolsets with features not defined in this document (e.g. enabled by the
newer software version) are not supported.
pmempool feature command is not fail safe.
-
$ pmempool feature --enable CHECKSUM_2K pool.set
Enables POOL_FEAT_CKSUM_2K incompat feature flag.
-
$ pmempool feature --disable CHECKSUM_2K pool.set
Disables POOL_FEAT_CKSUM_2K incompat feature flag.
-
$ pmempool feature --query CHECKSUM_2K pool.set
0
Prints POOL_FEAT_CKSUM_2K incompat feature flag value.
poolset(5) and <http://pmem.io>