1 .TH LFS-SETDIRSTRIPE 1 2017-11-07 "Lustre" "Lustre Utilities"
3 lfs setdirstripe, mkdir \- set striping pattern of a directory.
5 .B lfs setdirstripe [\fR-cCdDhHioTxX\fR] \fIDIR\fR...
8 Create a striped directory with specified striping pattern. This
10 sub-command is similar to
12 but is used to create a striped directory or set the default layout for
14 Can also be used to create directory with a foreign (free format) striping pattern (see
20 is an alias for this command.
23 .BR \-c ", " \-T ", " \-\-mdt\-count =\fICOUNT\fR
24 Stripe the new directory over
28 .B -C\fR, \fB--overstripe-count \fISTRIPE_COUNT\fR
29 The number of stripes to create, creating > 1 stripe MDT if \fISTRIPE_COUNT\fR
30 exceeds the number of MDTs in the file system. \fB0 \fRmeans to use the
31 filesystem-wide default stripe count (default 1), and \fB-1 \fRmeans to stripe
32 over all available MDTs. Max of 5 stripes/MDT.
37 .BR \-i ", " \-\-mdt\-index =\fISTART_MDT_INDEX\fR[,\fIMDT_INDEX ...]
38 Use the MDT whose index is
40 as the master/starting MDT for the directory. If multiple
42 values are given, then the stripes will be allocated on the specified
45 (default) is used, the client will round-robin subdirectory creation
46 across all MDTs if their free space is within
47 .B lod.*.mdt_qos_threshold_rr
48 percent of each other, otherwise the client will prefer to select
50 MDT(s) proportional to the free space and inodes on each.
54 values while trying to set the default striping pattern of subdirectories using
56 will not load balance subdirectory creation amongst the MDTs. Instead, this
57 will cause all new subdirectories to be striped across all of the specified
58 MDTs. This is discouraged and can lead to filesystem problems if too many
59 striped directories are created. To do this anyway,
61 must also be specified, where
63 matches the number of MDT indices given.
65 .BR \-H ", " \-\-mdt-hash =\fIHASH_TYPE\fR
68 for the striped directory.
72 CRUSH hash algorithm. This is a consistent hash
73 algorithm, so minimum sub files need to relocate
74 during directory restripe.
77 Fowler-Noll-Vo (FNV-1a) hash algorithm. This provides
78 reasonably uniform, but not cryptographically strong,
79 hashing of the filename. (default)
82 Sum of ASCII characters modulo number of MDTs. This
83 provides weak hashing of the filename, and is suitable
84 for only testing or when the input is known to have
85 perfectly uniform distribution (e.g. sequential numbers).
88 .BR \-d ", " \-\-delete
89 Delete the default striping layout from the directory. New subdirectories
90 created in this directory will inherit the global default directory layout
91 (by default they will not be striped).
93 .BR \-D ", " \-\-default
94 Set the default striping pattern of subdirectories. Newly created
95 sub-directories will use the new default striping pattern,
96 but existing sub-directories will not be affected. The newly
97 created sub-directories will also inherit the specified default
100 Note that striping all directories across all MDTs by default is
102 recommended at this time, as the clients will have to do more RPCs to
103 create and access each directory, hurting performance rather than
104 improving it. Default striped directories are preferred only for
105 parent directories where large subdirectories will be created
106 (e.g. file-per-process job output directories). Instead, using
108 on top-level directories balances mkdir therein over MDTs automatically
109 without causing all subdirectories to be remote by default.
111 .BR \-o ", " \-\-mode =\fIMODE\fR
112 Set the file access permissions of the new directory to the specified
115 (typically octal), as with
117 It is not affected by the current
120 .BR \-\-foreign[=type]
121 Create a directory with a foreign (non-Lustre/free format, see
123 option) striping. Where
125 specifies a known foreign type (like
129 , ...) or a 32-bit numeric type.
131 .BR \-\-flags =\fI<hex>\fR
132 Specify a numeric bitmask of type-specific layout flags for the foreign layout.
134 .BR \-x ", " \-\-xattr =\fISTRING\fR
135 Specify a string to be used as a foreign (free format) striping.
137 .BR \-X ", " \-\-max-inherit = \fIMAX_INHERIT
138 Set the inherit depth of default directory layout. If non-zero, then
140 is the number of subdirectory levels for which this default layout is inherited,
141 up to a maximum of 250 levels, and is decremented by one when copying the
142 default layout to each new subdirectory, until zero and the default layout is
145 of -1 means the default layout is inherited for all subdirectories.
147 .BR \-\-max-inherit-rr = \fIMAX_INHERIT_RR
148 Set the round-robin inherit depth of the default directory layout, only when
152 is zero (unset), then new subdirectories are preferentially created on MDTs
153 with more free space and inodes if the MDTs are imbalanced. If non-zero, then
155 is the number of subdirectory levels, up to a maximum of 250 levels, for which
156 new subdirectories will be created in a round-robin manner across all available
157 MDTs, rather than using MDT space balancing for new subdirectories. Otherwise,
159 is decremented by one when copying the default layout to each new subdirectory,
160 until zero and round-robin is no longer used. It may be useful to set
162 to 2 or 3 when setting the default directory layout on the root of a
164 filesystem, so that top-level subdirectories are immediately spread
165 across MDTs, rather than waiting for the MDTs to become imbalanced.
166 Round-robin subdirectory creation is unlikely to be useful for existing
167 filesystems that already have many files and imbalanced MDTs, since space
168 balancing will already happen, and this will unnecessarily increase the number
169 of remote subdirectories (increasing overhead) without any benefit.
180 and create the directory on an MDT that is less full than the others.
184 command is only usable by root unless the
185 .B "mdt.*.enable_remote_dir_gid"
186 is set on the MDS via
188 to be either a non-zero numeric GID to limit it to a single group (e.g. the
189 .BR "operator " or " admin"
192 to allow any user/group to create remote directories. By default, it is
194 to limit remote/striped directories to only the root user.
196 The root directory of the file system is on MDT0000, and a filesystem-wide
197 default directory layout is set on it by default:
198 .B lfs setdirstripe -D -i -1 -c 1 --max-inherit -1 --max-inherit-rr 3
199 , which is a space balanced directory layout, therefore new directories will be
200 created on all MDTs by inode and space usage, and the top three level of new
201 directories will be created in roundrobin mode if system is balanced. If user
202 doesn't want automatic space balance, deleting this default directory layout
203 won't work, because it will be recreated if not set, instead user can run
204 .B lfs setdirstripe -D -i -1 -c 1 --max-inherit 1 <mountpoint>
205 to limit space balance in the top level, or run
206 .B lfs setdirstripe -D -i 0 -c 1 --max-inherit 1 <mountpoint>
211 .B $ lfs setdirstripe -c 2 -i 1 -H all_char /mnt/lustre/dir1
212 This creates a directory striped on two MDTs, whose first stripe is on
214 (MDT index 1), and whose hash type is
217 .B $ lfs mkdir --foreign=symlink --xattr PUUID/CUUID /mnt/lustre/dir1
220 with foreign (non-lustre/free format)
222 striping/LMV EA value (symlink type).
226 command is part of the Lustre filesystem.
230 .BR lfs-getdirstripe (1),
231 .BR lfs-setstripe (1),