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Diffstat (limited to 'Documentation/btrfs-balance.asciidoc')
| -rw-r--r-- | Documentation/btrfs-balance.asciidoc | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/Documentation/btrfs-balance.asciidoc b/Documentation/btrfs-balance.asciidoc index c8407419..7df40b9c 100644 --- a/Documentation/btrfs-balance.asciidoc +++ b/Documentation/btrfs-balance.asciidoc @@ -11,7 +11,7 @@ SYNOPSIS DESCRIPTION ----------- -The primary purpose of the balance feature is to spread block groups accross +The primary purpose of the balance feature is to spread block groups across all devices so they match constraints defined by the respective profiles. See `mkfs.btrfs`(8) section 'PROFILES' for more details. The scope of the balancing process can be further tuned by use of filters that @@ -67,6 +67,12 @@ resume interrupted balance start the balance operation according to the specified filters, no filters will rewrite the entire filesystem. The process runs in the foreground. + +NOTE: the balance command without filters will basically rewrite everything +in the filesystem. The run time is potentially very long, depending on the +filesystem size. To prevent starting a full balance by accident, the user is +warned and has a few seconds to cancel the operation before it starts. The +warning and delay can be skipped with '--full-balance' option. ++ `Options` + -d[<filters>]:::: @@ -93,7 +99,7 @@ moving data from single to RAID1). This functionality is accessed through the '-d', '-m' or '-s' options to btrfs balance start, which filter on data, metadata and system blocks respectively. -A filter has the following stucture: 'type'[='params'][,'type'=...] +A filter has the following structure: 'type'[='params'][,'type'=...] The available types are: @@ -106,7 +112,7 @@ are a list of profile names separated by "'|'" (pipe). Balances only block groups with usage under the given percentage. The value of 0 is allowed and will clean up completely unused block groups, this should not require any new work space allocated. You may want to use 'usage=0' -in case balance is returnin ENOSPC and your filesystem is not too full. +in case balance is returning ENOSPC and your filesystem is not too full. + The argument may be a single value or a range. The single value 'N' means 'at most N percent used', equivalent to '..N' range syntax. Kernels prior to 4.4 @@ -147,7 +153,7 @@ only the single value format. The range minimum and maximum are inclusive. *stripes=<range>*:: Balance only block groups which have the given number of stripes. The parameter -is a range specified as 'start..end'. Makes sense fo block group profiles that +is a range specified as 'start..end'. Makes sense for block group profiles that utilize striping, ie. RAID0/10/5/6. The range minimum and maximum are inclusive. @@ -192,7 +198,7 @@ command: An example of a filter that does not require workspace is 'usage=0'. This will scan through all unused block groups of a given type and will reclaim the -space. Ater that it might be possible to run other filters. +space. After that it might be possible to run other filters. **CONVERSIONS ON MULTIPLE DEVICES** |