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authorDavid Teigland <teigland@redhat.com>2017-04-10 16:29:40 -0500
committerDavid Teigland <teigland@redhat.com>2017-04-11 10:21:36 -0500
commit21da004e58cdd406d5de0d67f27686373d7d2bfe (patch)
tree1f43737d602f937f6fd410ee542f8a7a46a9cbf7 /man/lvconvert.8_des
parenta4f07b701a009aba2ceca7fdb4ef880505ad54c3 (diff)
downloadlvm2-21da004e58cdd406d5de0d67f27686373d7d2bfe.tar.gz
man lvcreate/lvconvert: minor clean up rewording
Diffstat (limited to 'man/lvconvert.8_des')
-rw-r--r--man/lvconvert.8_des81
1 files changed, 44 insertions, 37 deletions
diff --git a/man/lvconvert.8_des b/man/lvconvert.8_des
index dc51aaede..6fd1ed9cd 100644
--- a/man/lvconvert.8_des
+++ b/man/lvconvert.8_des
@@ -7,6 +7,17 @@ To display the current LV type, run the command:
.B lvs -o name,segtype
.I LV
+In some cases, an LV is a single device mapper (dm) layer above physical
+devices. In other cases, hidden LVs (dm devices) are layered between the
+visible LV and physical devices. LVs in the middle layers are called sub LVs.
+A command run on a visible LV sometimes operates on a sub LV rather than
+the specified LV. In other cases, a sub LV must be specified directly on
+the command line.
+
+Sub LVs can be displayed with the command:
+
+.B lvs -a
+
The
.B linear
type is equivalent to the
@@ -20,45 +31,41 @@ type is deprecated and the
.B raid1
type should be used. They are both implementations of mirroring.
-In some cases, an LV is a single device mapper (dm) layer above physical
-devices. In other cases, hidden LVs (dm devices) are layered between the
-visible LV and physical devices. LVs in the middle layers are called sub LVs.
-A command run on a visible LV sometimes operates on a sub LV rather than
-the specified LV. In other cases, a sub LV must be specified directly on
-the command line.
-
Striped raid types are
-.B raid0/raid0_meta
-,
-.B raid5
-(an alias for raid5_ls),
-.B raid6
-(an alias for raid6_zr) and
-.B raid10
-(an alias for raid10_near).
+\fBraid0/raid0_meta\fP,
+\fBraid5\fP (an alias for raid5_ls),
+\fBraid6\fP (an alias for raid6_zr) and
+\fBraid10\fP (an alias for raid10_near).
As opposed to mirroring, raid5 and raid6 stripe data and calculate parity
-blocks. The parity blocks can be used for data block recovery in case devices
-fail. A maximum number of one device in a raid5 LV may fail and two in case
-of raid6. Striped raid types typically rotate the parity blocks for performance
-reasons thus avoiding contention on a single device. Layouts of raid5 rotating
-parity blocks can be one of left-asymmetric (raid5_la), left-symmetric (raid5_ls
-with alias raid5), right-asymmetric (raid5_ra), right-symmetric (raid5_rs) and raid5_n,
-which doesn't rotate parity blocks. Any \"_n\" layouts allow for conversion between
-raid levels (raid5_n -> raid6 or raid5_n -> striped/raid0/raid0_meta).
-raid6 layouts are zero-restart (raid6_zr with alias raid6), next-restart (raid6_nr),
-next-continue (raid6_nc). Additionally, special raid6 layouts for raid level conversions
-between raid5 and raid6 are raid6_ls_6, raid6_rs_6, raid6_la_6 and raid6_ra_6. Those
-correspond to their raid5 counterparts (e.g. raid5_rs can be directly converted to raid6_rs_6
-and vice-versa).
-raid10 (an alias for raid10_near) is currently limited to one data copy and even number of
-sub LVs. This is a mirror group layout thus a single sub LV may fail per mirror group
-without data loss.
-Striped raid types support converting the layout, their stripesize
-and their number of stripes.
+blocks. The parity blocks can be used for data block recovery in case
+devices fail. A maximum number of one device in a raid5 LV may fail, and
+two in case of raid6. Striped raid types typically rotate the parity and
+data blocks for performance reasons, thus avoiding contention on a single
+device. Specific arrangements of parity and data blocks (layouts) can be
+used to optimize I/O performance, or to convert between raid levels. See
+\fBlvmraid\fP(7) for more information.
-The striped raid types combined with raid1 allow for conversion from linear -> striped/raid0/raid0_meta
-and vice-versa by e.g. linear <-> raid1 <-> raid5_n (then adding stripes) <-> striped/raid0/raid0_meta.
+Layouts of raid5 rotating parity blocks can be: left-asymmetric
+(raid5_la), left-symmetric (raid5_ls with alias raid5), right-asymmetric
+(raid5_ra), right-symmetric (raid5_rs) and raid5_n, which doesn't rotate
+parity blocks. Layouts of raid6 are: zero-restart (raid6_zr with alias
+raid6), next-restart (raid6_nr), and next-continue (raid6_nc).
-Sub LVs can be displayed with the command
-.B lvs -a
+Layouts including _n allow for conversion between raid levels (raid5_n to
+raid6 or raid5_n to striped/raid0/raid0_meta). Additionally, special raid6
+layouts for raid level conversions between raid5 and raid6 are:
+raid6_ls_6, raid6_rs_6, raid6_la_6 and raid6_ra_6. Those correspond to
+their raid5 counterparts (e.g. raid5_rs can be directly converted to
+raid6_rs_6 and vice-versa).
+
+raid10 (an alias for raid10_near) is currently limited to one data copy
+and even number of sub LVs. This is a mirror group layout, thus a single
+sub LV may fail per mirror group without data loss.
+
+Striped raid types support converting the layout, their stripesize and
+their number of stripes.
+
+The striped raid types combined with raid1 allow for conversion from
+linear -> striped/raid0/raid0_meta and vice-versa by e.g. linear <-> raid1
+<-> raid5_n (then adding stripes) <-> striped/raid0/raid0_meta.