DragonFly On-Line Manual Pages
CHECKPT(1) DragonFly General Commands Manual CHECKPT(1)
checkpt -- resume checkpointed program
checkpt -r file.ckpt
The checkpt utility will resume the checkpointed program from the speci-
fied checkpoint file. Programs can be checkpointed using ^E.
By default, only members of the wheel group can checkpoint a program.
The group can be changed with the sysctl kern.ckptgroup. The checkpoint
file template can be changed with the sysctl kern.ckptfile.
The checkpointing utility is fairly primitive. Only programs operating
on normal files can be properly restored. Programs which operate on
devices, sockets, or pipes (including piped commands) cannot be com-
pletely. File descriptors 0, 1, and 2, are not saved and the restored
program will inherit the descriptors from checkpt.
Programs can actively support checkpointing by catching the SIGCKPT sig-
nal, cleaning up, and manually calling the sys_checkpoint() system call.
The program can then choose whether to continue running or exit. The
resumed program will get a (typically) positive return value from
sys_checkpoint() which it can use to determine whether it just made the
system call or whether it is being resumed from the system call. The
program can then reconstruct non-checkpointed elements and resume.
The checkpt command first appeared in DragonFly 1.0.
DragonFly 5.3 October 19, 2003 DragonFly 5.3
CHECKPOINT(7) SQL Commands CHECKPOINT(7)
CHECKPOINT - force a transaction log checkpoint
Write-Ahead Logging (WAL) puts a checkpoint in the transaction log
every so often. (To adjust the automatic checkpoint interval, see the
run-time configuration options checkpoint_segments and checkpoint_time-
out.) The CHECKPOINT command forces an immediate checkpoint when the
command is issued, without waiting for a scheduled checkpoint.
A checkpoint is a point in the transaction log sequence at which all
data files have been updated to reflect the information in the log. All
data files will be flushed to disk. Refer to in the documentation for
more information about the WAL system.
Only superusers can call CHECKPOINT. The command is not intended for
use during normal operation.
The CHECKPOINT command is a PostgreSQL language extension.
SQL - Language Statements 2014-07-21 CHECKPOINT(7)