From 8c5db79d0f3bd392b2d0965a4444de7726012bee Mon Sep 17 00:00:00 2001 From: Nicholas D Steeves Date: Thu, 7 Dec 2017 21:26:09 +0100 Subject: btrfs-progs: docs: annual typo, clarity, & grammar review & fixups Signed-off-by: Nicholas D Steeves Signed-off-by: David Sterba --- Documentation/btrfs-balance.asciidoc | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'Documentation/btrfs-balance.asciidoc') diff --git a/Documentation/btrfs-balance.asciidoc b/Documentation/btrfs-balance.asciidoc index cc81de91..7017bed7 100644 --- a/Documentation/btrfs-balance.asciidoc +++ b/Documentation/btrfs-balance.asciidoc @@ -21,8 +21,8 @@ filesystem. The balance operation is cancellable by the user. The on-disk state of the filesystem is always consistent so an unexpected interruption (eg. system crash, reboot) does not corrupt the filesystem. The progress of the balance operation -is temporarily stored and will be resumed upon mount, unless the mount option -'skip_balance' is specified. +is temporarily stored as an internal state and will be resumed upon mount, +unless the mount option 'skip_balance' is specified. WARNING: running balance without filters will take a lot of time as it basically rewrites the entire filesystem and needs to update all block pointers. @@ -201,10 +201,11 @@ ENOSPC ------ The way balance operates, it usually needs to temporarily create a new block -group and move the old data there. For that it needs work space, otherwise -it fails for ENOSPC reasons. +group and move the old data there, before the old block group can be removed. +For that it needs the work space, otherwise it fails for ENOSPC reasons. This is not the same ENOSPC as if the free space is exhausted. This refers to -the space on the level of block groups. +the space on the level of block groups, which are bigger parts of the filesytem +that contain many file extents. The free work space can be calculated from the output of the *btrfs filesystem show* command: @@ -227,7 +228,7 @@ space. After that it might be possible to run other filters. Conversion to profiles based on striping (RAID0, RAID5/6) require the work space on each device. An interrupted balance may leave partially filled block -groups that might consume the work space. +groups that consume the work space. EXAMPLES -------- @@ -238,7 +239,7 @@ can be found in section 'TYPICAL USECASES' of `btrfs-device`(8). MAKING BLOCK GROUP LAYOUT MORE COMPACT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -The layout of block groups is not normally visible, most tools report only +The layout of block groups is not normally visible; most tools report only summarized numbers of free or used space, but there are still some hints provided. @@ -298,7 +299,7 @@ data to the remaining blockgroups, ie. the 6GiB are now free of filesystem structures, and can be reused for new data or metadata block groups. We can do a similar exercise with the metadata block groups, but this should -not be typically necessary, unless the used/total ration is really off. Here +not typically be necessary, unless the used/total ratio is really off. Here the ratio is roughly 50% but the difference as an absolute number is "a few gigabytes", which can be considered normal for a workload with snapshots or reflinks updated frequently. -- cgit v1.2.3