diff options
Diffstat (limited to 'share/man/man4/ccd.4')
| -rw-r--r-- | share/man/man4/ccd.4 | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/share/man/man4/ccd.4 b/share/man/man4/ccd.4 index 0962fa0..17c6651 100644 --- a/share/man/man4/ccd.4 +++ b/share/man/man4/ccd.4 @@ -69,9 +69,9 @@ pseudo-device ccd 4 # concatenated disk devices .Ed .Pp The count argument is how many -.Nm ccds +.Nm Ns 's memory is allocated for a boot time. In this example, no more than 4 -.Nm ccds +.Nm Ns s may be configured. As of the .Fx 3.0 release, you do not need to @@ -81,19 +81,19 @@ module. Simply running will load the module into the kernel. .Pp A -.Nm ccd +.Nm may be either serially concatenated or interleaved. To serially concatenate the partitions, specify the interleave factor of 0. Note that mirroring may not be used with an interleave factor of 0. .Pp There is a run-time utility that is used for configuring -.Nm ccds . +.Nm Ns s . See .Xr ccdconfig 8 for more information. .Ss The Interleave Factor If a -.Nm ccd +.Nm is interleaved correctly, a .Dq striping effect is achieved, which can increase sequential read/write @@ -124,13 +124,13 @@ disk types. For random-access oriented workloads, such as news servers, a larger interleave factor (e.g., 65,536) is more desirable. Note that there isn't much -.Nm ccd +.Nm can do to speed up applications that are seek-time limited. Larger interleave factors will at least reduce the chance of having to seek two disk-heads to read one directory or a file. .Ss Disk Mirroring You can configure the -.Nm ccd +.Nm to .Dq mirror any even number of disks. See @@ -142,7 +142,7 @@ the mirror. A read will be run to either side of the mirror depending on what the driver believes to be most optimal. If the read fails, the driver will automatically attempt to read the same sector from the other side of the mirror. Currently -.Nm ccd +.Nm uses a duel seek zone model to optimize reads for a multi-tasking load rather then a sequential load. .Pp @@ -152,20 +152,20 @@ failure, you can use to recover the failed disk. .Pp Note that a one-disk -.Nm ccd +.Nm is not the same as the original partition. In particular, this means if you have a filesystem on a two-disk mirrored -.Nm ccd +.Nm and one of the disks fail, you cannot mount and use the remaining partition as itself; you have to configure it as a one-disk -.Nm ccd. +.Nm . You cannot replace a disk in a mirrored -.Nm ccd +.Nm partition without first backing up the partition, then replacing the disk, then restoring the partition. .Sh WARNINGS If just one (or more) of the disks in a -.Nm ccd +.Nm fails, the entire file system will be lost unless you are mirroring the disks. .Pp @@ -177,7 +177,7 @@ write error occurs, you should recover and regenerate the data as soon as possible. .Pp Changing the interleave or other parameters for a -.Nm ccd +.Nm disk usually destroys whatever data previously existed on that disk. .Sh FILES /dev/{,r}ccd* - ccd device special files. |
