.Sh SYSCTLS

gjournal adds the sysctl level kern.geom.journal

The string and integer information available

is detailed below.

The changeable column shows whether a process with appropriate

privilege may change the value.

.Bl -column "accept_immediatelyXXXXXX" integerXXX -offset indent

.It Sy "sysctl name	Type	Changeable"

.It "debug	integer	yes"

.It "switch_time	integer	yes"

.It "force_switch	integer	yes"

.It "parallel_flushes	integer	yes"

.It "accept_immediately	integer	yes"

.It "parallel_copies	integer	yes"

.It "record_entries	integer	yes"

.It "optimize	integer	yes"

.E1

.Pp

.B1 -tag -width 6n

.It Li debug

Setting a non-zero value enables debugging at various levels. Debug level 1 will record actions at a journal level, relating to journal switches, metadata updates etc. Debug level 2 will record actions at a higher level, relating to the numbers of entries in journals, access requests etc. Debug level 3 will record verbose detail, including insetion of I/Os to the journal.

.It Li switch_time

The maximum number of seconds a journal is allowed to remain open before switching to a new journal.

.It Li force_switch

Force a journal switch when the journal uses more than N% of the free journal space.

.It Li parallel_flushes

The number of flush I/O requests to be sent in parallel when flushing the journal to the data provider.

.It Li accept_immediately

The maximum number of I/O requests accepted at the same time.

.It Li parallel_copies

The number of copy I/O requests to send in parallel.

.It Li record_entries

The maximum number of record entries to allow in a single journal.

.It Li optimize

Controls whether entries in a journal will be optimized, by combining overlapping I/Os into a single I/O, and reordering the entries in a journal. This can be disabled by setting the sysctl to 0.

.E1

.Ss cache

The string and integer information available for the cache level

is detailed below.

The changeable column shows whether a process with appropriate

privilege may change the value.

.Bl -column "alloc_failuresXXXXXX" integerXXX -offset indent

.It Sy "sysctl name	Type	Changeable"

.It "used	integer	no"

.It "limit	integer	yes"

.It "divisor	integer	no"

.It "switch	integer	yes"

.It "misses	integer	yes"

.It "alloc_failures	integer	yes"

.E1

.Pp

.B1 -tag -width 6n

.It Li used

The number of bytes currently allocated to the cache.

.It Li limit

The maximum number of bytes to be allocated to the cache.

.It Li divisor

Sets the cache size to be used as a proportion of kmem_size. A value of 2 (the default) will cause the cache size to be set to 1/2 of the kmem_size.

.It Li switch

Force a journal switch when this percentage of cache has been used.

.It Li misses

The number of cache misses, when data has been read, but was not found in the cache.

.It Li alloc_failures

The number of times memory failed to be allocated to the cache because the cache limit was hit.

.E1

.Ss statistics

The string and integer information available for the statistics level

is detailed below.

The changeable column shows whether a process with appropriate

privilege may change the value.

.Bl -column "skipped_bytesXXXXXX" integerXXX -offset indent

.It Sy "sysctl name     Type    Changeable"

.It "skipped_bytes       integer yes"

.It "combined_ios      integer yes"

.It "switches    integer yes"

.It "wait_for_copy     integer yes"

.It "journal_full    integer yes"

.It "low_mem     integer yes"

.E1

.Pp

.B1 -tag -width 6n

.It Li skipped_bytes

The number of bytes skipped.

.It Li combined_ios

The number of I/Os which were combined by journal optimization.

.It Li switches

The number of journal switches.

.It Li wait_for_copy

The number of times the journal switch process had to wait for the previous journal copy to complete.

.It Li journal_full

The number of times the journal was almost full, forcing a journal switch.

.It Li low_mem

The number of times the low_mem hook was called.

.E1