.SH NAME
lfs setdirstripe, mkdir \- set striping pattern of a directory.
.SH SYNOPSIS
-.B lfs setdirstripe [\fR-cdDHioTx\fR] \fIDIR\fR...
+.B lfs setdirstripe [\fR-cdDhHioTxX\fR] \fIDIR\fR...
.br
.SH DESCRIPTION
Create a striped directory with specified striping pattern. This
.I COUNT
MDTs.
.TP
+.BR \-h ", " \-\-help
+Print usage message.
+.TP
.BR \-i ", " \-\-mdt\-index =\fISTART_MDT_INDEX\fR[,\fIMDT_INDEX ...]
Use the MDT whose index is
.I START_MDT_INDEX
as the master/starting MDT for the directory. If multiple
.I MDT_INDEX
values are given, then the stripes will be allocated on the specified
-MDT indices. If index -1 (default) is used, it will prefer to select
+MDT indices. If
+.B -1
+(default) is used, the client will round-robin subdirectory creation
+across all MDTs if their free space is within
+.B lod.*.mdt_qos_threshold_rr
+percent of each other, otherwise the client will prefer to select
.B COUNT
-MDTs proportional to the free space and inodes on each.
+MDT(s) proportional to the free space and inodes on each.
.TP
.BR \-H ", " \-\-mdt-hash =\fIHASH_TYPE\fR
Use
sub-directories will use the new default striping pattern,
but existing sub-directories will not be affected. The newly
created sub-directories will also inherit the specified default
-striping pattern. Only default stripe count is supported for now.
+striping pattern.
Note that striping all directories across all MDTs by default is
.B not
recommended at this time, as the clients will have to do more RPCs to
create and access each directory, hurting performance rather than
-improving it. Default striped directories are preferred for parent
-directories
-where large subdirectories will be created (e.g. file-per-process
-job output directories).
+improving it. Default striped directories are preferred only for
+parent directories where large subdirectories will be created
+(e.g. file-per-process job output directories). Instead, using
+.B -c 1 -i -1
+on top-level directories balances mkdir therein over MDTs automatically
+without causing all subdirectories to be remote by default.
.TP
.BR \-o ", " \-\-mode =\fIMODE\fR
Set the file access permissions of the new directory to the specified
option) striping. Where
.BR type
specifies a known foreign type (like
-.BR none ,
-.BR daos )
-or a 32-bit numeric type.
+.BR none
+,
+.BR symlink
+, ...) or a 32-bit numeric type.
.TP
.BR \-\-flags =\fI<hex>\fR
Specify a numeric bitmask of type-specific layout flags for the foreign layout.
.TP
.BR \-x ", " \-\-xattr =\fISTRING\fR
Specify a string to be used as a foreign (free format) striping.
+.TP
+.BR \-X ", " \-\-max-inherit = \fIMAX_INHERIT
+Set the inherit depth of default directory layout. If non-zero, then
+.I MAX_INHERIT
+is the number of subdirectory levels for which this default layout is inherited,
+up to a maximum of 250 levels, and is decremented by one when copying the
+default layout to each new subdirectory, until zero and the default layout is
+no longer copied. A
+.I MAX_INHERIT
+of -1 means the default layout is inherited for all subdirectories.
+.TP
+.BR \-\-max-inherit-rr = \fIMAX_INHERIT_RR
+Set the round-robin inherit depth of the default directory layout, only when
+.I START_MDT_INDEX
+is -1. If
+.I MAX_INHERIT_RR
+is zero (unset), then new subdirectories are preferentially created on MDTs
+with more free space and inodes if the MDTs are imbalanced. If non-zero, then
+.I MAX_INHERIT_RR
+is the number of subdirectory levels, up to a maximum of 250 levels, for which
+new subdirectories will be created in a round-robin manner across all available
+MDTs, rather than using MDT space balancing for new subdirectories. Otherwise,
+.I MAX_INHERIT_RR
+is decremented by one when copying the default layout to each new subdirectory,
+until zero and round-robin is no longer used. It may be useful to set
+.I MAX_INHERIT_RR
+to 2 or 3 when setting the default directory layout on the root of a
+.B new
+filesystem, so that top-level subdirectories are immediately spread
+across MDTs, rather than waiting for the MDTs to become imbalanced.
+Round-robin subdirectory creation is unlikely to be useful for existing
+filesystems that already have many files and imbalanced MDTs, since space
+balancing will already happen, and this will unnecessarily increase the number
+of remote subdirectories (increasing overhead) without any benefit.
.SH NOTE
.PP
+If neither
+.B -c
+or
+.B -i
+are specified,
+.B lfs mkdir
+will default to
+.B -c 1 -i -1
+and create the directory on an MDT that is less full than the others.
+.PP
The
.B lfs setdirstripe
command is only usable by root unless the
.B "0"
to limit remote/striped directories to only the root user.
-The root directory of the file system is on MDT0000, and directories and
-files inherit the MDT of their parent directory unless a different MDT is
-specified with this command.
+The root directory of the file system is on MDT0000, and a filesystem-wide
+default directory layout is set on it by default:
+.B lfs setdirstripe -D -i -1 -c 1 --max-inherit -1 --max-inherit-rr 3
+, which is a space balanced directory layout, therefore new directories will be
+created on all MDTs by inode and space usage, and the top three level of new
+directories will be created in roundrobin mode if system is balanced. If user
+doesn't want automatic space balance, deleting this default directory layout
+won't work, because it will be recreated if not set, instead user can run
+.B lfs setdirstripe -D -i -1 -c 1 --max-inherit 1 <mountpoint>
+to limit space balance in the top level, or run
+.B lfs setdirstripe -D -i 0 -c 1 --max-inherit 1 <mountpoint>
+to disable it.
-By default, only directories on MDT0000 can contain directories that are not on
-the same MDT. However, if
-.B "mdt.*.enable_remote_dir"
-is set non-zero on an MDT (the default)
-then it will allow creating remote directories that have parents other than
-MDT0000. This is restricted to avoid creating directory trees that have
-intermediate path components on a series different MDTs and become unavailable
-if any of the intermediate MDTs are offline.
.SH EXAMPLES
.TP
.B $ lfs setdirstripe -c 2 -i 1 -H all_char /mnt/lustre/dir1
(MDT index 1), and whose hash type is
.BR all_char .
.TP
-.B $ lfs mkdir --foreign=daos --xattr PUUID:CUUID /mnt/lustre/dir1
+.B $ lfs mkdir --foreign=symlink --xattr PUUID/CUUID /mnt/lustre/dir1
This creates
.B dir1
with foreign (non-lustre/free format)
-.B PUUID:CUUID
-striping/LMV EA.
+.B PUUID/CUUID
+striping/LMV EA value (symlink type).
.SH AVAILABILITY
The
.B lfs setdirstripe
git://git.whamcloud.com / fs / lustre-release.git / blobdiff