.TH bcacheadm 8
.SH NAME
bcacheadm \- manage bcache devices

.SH  SYNOPSIS
.B bcacheadm
[\fIoptions\fR]
.B COMMAND
[\fIoptions\fR]

.SH COMMANDS
.TP
.BR format
.RS
Format one or a list of devices with bcache data structures. You need to do this before you create a volume.
.RE

.BR register
.RS
Register a list of devices.
.RE

.BR list-cachesets
.RS
List cachesets on this system. This just searches /sys/fs/bcache.
.RE

.BR query-devs
.RS
Gives info about the superblock for a list of devices.
.RE

.BR status
.RS
Finds the status of the most up to date superblock in each tier. Pass in a list of devices.
.RE

.BR stats
.RS
List bcache specific statistics. Use --list to find out exactly what these are. To list stats for a cacheset, just give the cacheset uuid. To target a cache within the cacheset, use the -c option. To get time interval stats, use the hour, day, etc, options.
.RE

.BR probe
.RS
Return UUID if device identified as bcache-formatted.
.PP
Only necessary until support for the bcache superblock is included
in blkid; in the meantime, provides just enough functionality for a udev script
to create the /dev/disk/by-uuid symlink.
.RE

.BR help
.RS
List the bcacheadm commands
.RE

.SH OPTIONS
.SH Options for bcacheadm
.TP
.BR \--help


.SH Options for format
.TP
.BR \-C
Create a cache
.TP
.BR \-B
Create a backing device
.TP
.BR \-b\ --bucket-size=
Specifies the bucket size. Allocation is done in terms of buckets, and cache
hits are counted per bucket; thus a smaller bucket size will give better cache
utilization, but poorer write performance. The bucket size is intended to be
equal to the size of your SSD's erase blocks, which seems to be 128k-512k for
most SSDs. Must be a power of two; accepts human readable units. Defaults to
128k.
.TP
.BR \-l\ --label=
label
.TP
.BR \-w,\ --block=
block size (hard sector size of SSD, often 2k
.TP
.BR \-t,\ --tier=
tier of subsequent devices
.TP
.BR \--cache-replacement-policy=
one of lru, fifo, or random
.TP
.BR \-o,\ --data_offset=
data offset in sectors
.TP
.BR \--cset-uuid=
Create a cache device with the specified UUID
.TP
.BR \--csum_type=
One of none, csc32c, or csc64
.TP
.BR \--meta-replicas=
Number of metadata replicas
.TP
.BR \--data-replicas=
Number of data replicas
.TP
.BR \--wipe-bcache
Destroy existing bcache data if present
.TP
.BR \--discard
Enable discards
.TP
.BR \--writeback
Enable writeback

.SH Options for register

.SH Options for list-cachesets
.TP
.BR \-d,\ --dir=
Provide a directory other than /sys/fs/bcache

.SH Options for query-devs
.TP
.BR \-f,\ --force-csum
Enables bcacheadm to going even if the superblock crc is invalid

.SH Options for status

.SH Options for stats
.TP
.BR \-a,\ --all
List all stats and their values for the given device.
.TP
.BR \-l,\ --list
List the names of the different stats for the given device.
.TP
.BR \-u,\ --uuid=
UUID for the cacheset
.TP
.BR \-c,\ --cache=
Cache number, starts from 0
.TP
.BR \--five-min-stats
stats accumulated in the last 5 minutes
.TP
.BR \--hour-stats
stats accumulated in the last hour
.TP
.BR \--day-stats
stats accumulated in the last day
.TP
.BR \--total-stats
stats accumulated in total