.br
Create a new composite
.I file
-with one or more component layouts, or set or replace the default file layout
-on an existing
-.IR directory .
+with one or more component layouts (where \fIend\fR marks the end of the
+current component), or set or replace the default file layout on an existing
+.IR directory.
.TP
.B lfs setstripe --component-add -E \fIend1\fR [\fISTRIPE_OPTIONS\fR] \
... <\fIfile\fR>
Create a new
.I file
with a foreign/non-lustre layout of type
-.I foreign_type \fR(\fBnone\fR, \fBdaos\fR, ...)
+.I foreign_type \fR(\fBnone\fR, \fBsymlink\fR, ...)
with flags
.I hex
and a free-format layout value of
filesystem-wide default stripe count (default 1), and \fB-1 \fRmeans to stripe
over all available OSTs.
.TP
+.B -C\fR, \fB--overstripe-count \fR<\fIstripe_count\fR>
+The number of stripes to create, creating > 1 stripe per OST if count exceeds
+the number of OSTs in the file system. \fB0 \fRmeans to use the filesystem-wide
+default stripe count (default 1), and \fB-1 \fRmeans to stripe over all
+available OSTs.
+.TP
.B -S\fR, \fB--stripe-size \fR<\fIstripe_size\fR>
The number of bytes to store on each OST before moving to the next OST. A
stripe size of
.BR G ibibytes.
The
.I stripe_size
-must be a multiple of 64KiB in size.
+must be a multiple of 64KiB. Values below 4096 are assumed to be in KiB units.
.TP
.B -i\fR, \fB--stripe-index \fR<\fIstart_ost_index\fR>
The OST index (starting at 0) on which to start striping for this file. A
Current known types are
.BR none
and
-.BR daos
+.BR symlink
, default is
.BR none
.
means the following options extend to the end of the file. The first
component starts at offset 0, and each subsequent component starts at
the end of the previous component, so they must be specified in increasing
-file offset order.
+file offset order, and must be a multiple of 64KiB to align with the
+minimum
+.I stripe_size
+value. Values below 4096 are assumed to be in KiB units.
.PP
.RS
The first component specified will inherit default parameters from the
to add more components to the end of the file.
.RE
.TP
+.B -z, --extension-size, ext-size\fR <\fIext_size\fR>
+This option modifies the \fB-E\fR option, components which have this
+option specified are created as pairs of components, extendable and
+extension ones.
+.PP
+.RS
+The extendable component starts at offset 0 if this is the first
+component of the file. In this case it ends at offset \fIext_size\fR and
+it gets the flag \fBinit\fR (initialized). The extendable component starts
+at the end of the previous component if this is not the first component of
+the file. In this case it ends at the same offset (0-length component).
+.PP
+The extension component covers the rest of the specified region up to
+the \fIend\fR specified by \fB-E\fR option and gets the flag \fBextension\fR.
+This component covers the space reserved for the extendable component but
+not used immediately, the later extension of the extendable component is done
+by \fIext_size\fR each time until the extension component is used up. This is
+used to control the space on OSTs the stripe is located on, in case one of
+them is low on space, the remaining extension component region is added to the
+next component.
+.RE
+.TP
.B --component-add
Add components to the end an existing composite file. It is not possible
to add components incrementally to the default directory layout, since the
.B * prefer\fR - component preferred for read/write in a mirrored file
.RE
.RS
-.B * stale\fR - component has outdated data in a mirrored file. Once a
-component is marked
+.B * stale\fR - component has outdated data in a mirrored file. This flag is
+not allowed to be set on a component of the last non-stale mirror.
+Once a component is marked
.BR stale ,
it isn't permitted to clear this flag directly. \fBlfs-mirror-resync\fR(1)
is required to clear the flag.
covers [0, 4MiB), the second component has 4 stripes and covers [4MiB, 64MiB),
the last component stripes over all available OSTs and covers [64MiB, EOF).
.TP
+.B lfs setstripe -E -1 -z 64M /mnt/lustre/file1
+This creates a file with a composite layout, the component one covers [0, 64MiB)
+and the second component the rest [64MiB, EOF) originally. Once written beyond
+64MiB the component one is extended to [0, 128MiB), once written beyond 128MiB
+it is extended to [0, 192MiB), etc; the second component is shortened
+appropriately.
+.PP
+.RS
+When one of the OSTs of the first component layout is low on space, e.g. while
+writing beyond 192MiB, the first component is left as [0, 192MiB), and a new
+component is allocated between them, its layout repeats the first component
+layout but initialized on different OSTs so that the full OSTs are avoided.
+It is allocated and immediately extended to [192MiB, 256MiB), the following
+extension component is shortened again.
+.RE
+.TP
+.B lfs setstripe -E 1G -z 64M -E 100G -z 256M -E -1 -z 1G /mnt/lustre/file1
+This creates a file with a composite layout, the component one covers [0,
+64MiB), the third component covers [1G, 1G), the fifth component covers
+[100GiB, 100GiB) originally. The second, fourth and sixth extension components
+cover the left space accordingly. The process of writing is similar to above,
+but when one of the OSTs of the first component layout is low on space, e.g.
+while writing beyond 192MiB in the example above, the first component is left
+as [0, 192MiB), the second (extension) component is removed, and its range
+spills over to the third and the fourth components - they are moved left to
+start at 192MiB instead of 100GiB; the third component is immediately extended
+and becomes [192MiB, 448MiB), the fourth (the extension one) component becomes
+[448MiB, 100GiB).
+.TP
.B lfs setstripe --component-add -E eof -c 4 /mnt/lustre/file1
This add a component which starts at the end of last existing component to
the end of file.
.B lfs getstripe --yaml
command.
.TP
-.B lfs setstripe --foreign=daos --flags=0xda08 \
+.B lfs setstripe --foreign=symlink --flags=0xda08 \
--xattr=PUUID:CUUID /mnt/lustre/file1
This creates foreign
.BR file1
of type
-.BR daos
+.BR symlink
with non-lustre/free-format
.BR PUUID:CUUID
layout/LOV EA and flags
git://git.whamcloud.com / fs / lustre-release.git / blobdiff