diff options
Diffstat (limited to 'sbin/vinum/vinum.8')
| -rw-r--r-- | sbin/vinum/vinum.8 | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/sbin/vinum/vinum.8 b/sbin/vinum/vinum.8 index 1f6e319..119a5df 100644 --- a/sbin/vinum/vinum.8 +++ b/sbin/vinum/vinum.8 @@ -175,7 +175,7 @@ Write a copy of the current configuration to .It Ic quit Exit the .Nm -program when running in interactive mode. Normally this would be done by +utility when running in interactive mode. Normally this would be done by entering the .Dv EOF character. @@ -265,11 +265,11 @@ if no parameters are specified. Create a striped volume from the specified drives. .El .Sh DESCRIPTION +The .Nm -is a utility program to communicate with the kernel component of the Vinum +utility communicates with the kernel component of the Vinum logical volume manager. -.Nm -is designed either for interactive use, when started without command line +It is designed either for interactive use, when started without command line arguments, or to execute a single command if the command is supplied on the command line. In interactive mode, .Nm @@ -973,7 +973,7 @@ writes the list to .It Ic quit Exit the .Nm -program when running in interactive mode. Normally this would be done by +utility when running in interactive mode. Normally this would be done by entering the .Dv EOF character. @@ -986,7 +986,9 @@ command scans the specified disks for partitions containing previously created configuration information. It reads the configuration in order from the most recently updated to least recently updated configuration. +The .Nm +utility maintains an up-to-date copy of all configuration information on each disk partition. You must specify all of the slices in a configuration as the parameter to this command. @@ -1554,8 +1556,9 @@ S raid10.p1.s1 State: up PO: 279 kB Size: 573 MB In this case, the usable part of the volume is even smaller, since the first plex has shrunken to match the smallest drive. .Sh CONFIGURATION FILE +The .Nm -requires that all parameters to the +utility requires that all parameters to the .Ic create commands must be in a configuration file. Entries in the configuration file define volumes, plexes and subdisks, and may be in free format, except that each @@ -1610,7 +1613,9 @@ partition, which is reserved for the complete disk. Define the drive to be a .Dq hot spare drive, which is maintained to automatically replace a failed drive. +The .Nm +utility does not allow this drive to be used for any other purpose. In particular, it is not possible to create subdisks on it. This functionality has not been completely implemented. @@ -1637,8 +1642,9 @@ may be either .Cm round or .Cm prefer Ar plexname . +The .Nm -satisfies a read request from only one of the plexes. A +utility satisfies a read request from only one of the plexes. A .Cm round read policy specifies that each read should be performed from a different plex in @@ -1861,12 +1867,15 @@ is a swap partition, and partition .Dq Li c represents the whole disk and should not be used for any other purpose. .Pp +The .Nm +utility uses the first 265 sectors on each partition for configuration information, so the maximum size of a subdisk is 265 sectors smaller than the drive. .Sh LOG FILE +The .Nm -maintains a log file, by default +utility maintains a log file, by default .Pa /var/log/vinum_history , in which it keeps track of the commands issued to .Nm . @@ -2011,8 +2020,9 @@ filesystem is limited by the speed of the disk. By spreading the volume across multiple disks, you can increase the throughput in multi-access environments. This technique shows little or no performance improvement in single-access environments. +The .Nm -uses a technique called +utility uses a technique called .Dq striping , or sometimes RAID-0, to increase this concurrency of access. The name RAID-0 is misleading: striping does not provide any redundancy or additional reliability. @@ -2328,7 +2338,9 @@ load: 8.01 ms latency, 2 ms transfer, 10.01 ms total. It appears that some hardware RAID systems have problems with large stripes: they appear to always transfer a complete stripe to or from disk, so that a large stripe size will have an adverse effect on performance. +The .Nm +utility does not suffer from this problem: it optimizes all disk transfers and does not transfer unneeded data. .Pp @@ -2473,8 +2485,9 @@ This behaviour of is an invitation to shoot yourself in the foot: with .Nm ccd you can easily overwrite a filesystem. +The .Nm -will not permit this. +utility will not permit this. .Pp For similar reasons, the .Nm Ic start @@ -2510,8 +2523,9 @@ In practice, people aren't too interested in what was in the plex when it was created, and other volume managers cheat by setting them .Em up anyway. +The .Nm -provides two ways to ensure that newly created plexes are +utility provides two ways to ensure that newly created plexes are .Em up : .Bl -bullet .It @@ -2619,7 +2633,7 @@ The name of the editor to use for editing configuration files, by default .Sh HISTORY The .Nm -command first appeared in +utility first appeared in .Fx 3.0 . The RAID-5 component of .Nm |
