ref: ea50e8ab08f8c76c9bed6169cb2bd6ea2696f44e
dir: gefs/gefs.8.man
.TH GEFS 8 .SH NAME gefs \- file server maintenance .SH SYNOPSIS .PD 0 .PP .B check .PP .B df .PP .B halt .PP .B help .PP .B permit [ .B on | .BR off ] .PP .B save trace .I filename .PP .B snap [ -Smdl ] [ .I old [ .I new ] ] .PP .B sync .PP .B users .SH DESCRIPTION .IR Gefs (4) provides an administration console on .IR /srv/gefs.cmd . By default, this console is only readable and writable by the owner of the file system. .SH CONSOLE .PP The console handles the following commands: .PP .I Check applies basic consistency checks to the file system, reporting invalid blocks, broken metadata, and other similar structural issues. .PP .I Df prints the amount of used space and total space in megabytes, as well as the percentage of space occupied. .PP .I Halt syncs all IO to disk and exits the file system. While the syncing occurs, the file system does not allow new writes. .PP .I Help prints a summary of the available commands. This table includes additional debug commands that are subject to change, and are intentionally undocumented. .PP .I Permit [ .B on | .B off ] has two effects. First, if the user table is broken, it allows a fallback to a default user list. This allows the system administrator to recover if they reboot with a broken user file. Second, it allows mounts to occur in permissive mode by any user. Permissive mounts are designated by prefixing the attach spec with a .I % sigil. Permissive disables permissions checks when accessing files, and allows .IR wstat (5) to modify the owner of the file. This may be useful during file system initialization. .PP .B Snap manages snapshots. It can be invoked as .I snap .BR -l , .I snap .B -d .IR snap , or .I snap [ .B -flags ] .IR "old new" , which will list, delete, or create new snapshots respectively. It accepts the following options: .TP .B -l Lists snapshots and their attributes. .TP .BI "-d " snap Deletes a snapshot, reclaiming whatever space is not shared is not shared with other snapshots. .TP .B -m Flags that the newly created snapshot should be mutable. .TP .B -S Disables automatic snapshots. .I old and gives it the name .IR new . .PP .I Sync writes dirty blocks in memory to the disk. .PP .B Users attempts to reload the user table from .IR /adm/users . .PP .I save trace saves a trace of recent operations to a file. If a file is not specified, it prints to the console. .SH ADM FILES .PP Gefs supports independent snapshots in the same file system. As a result, global configuration needs to be separated from snapshots. The global configuration resides in a well known snapshot called .IR adm . .PP The adm snapshot would conventionally be mounted in .IR /adm . It contains the .IR users (6) file. .IR The .I users file is read at file system startup, or when the .I users command is run on the console. If the users file is malformed at file system start, then the file system will refuse to initialize. .I Permissive mode will allow the file system to fall back to a default users table. It will also allow any user to mount the .I adm snapshot: this can help recover from disasters. .PP The .B default table looks like this: .IP .EX -1:adm:adm: 0:none:: 1:$user:$user: .EE .PP Where .I $user is specified at the time that the file system is reamed. .SH EXAMPLES .PP To show current disk usage, the following may be written on the console: .IP .EX df .EE To create a new snapshot: .IP .EX snap main myimmutable .EE .PP To create a new mutable snapshot that does not take automatic checkpoints: .IP .EX snap -Sm main mymutable .EE .PP To delete a snapshot: .IP .EX snap -d mysnap .EE .SH BUGS .PP Currently, it's not possible to change the mutability of a snapshot. Instead, a new label needs to be created. .PP .SH SEE ALSO .IR gefs (4)