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Files larger than 4 TiB look, feel, and operate similarly to any other file under OneFS. As such, no special tools or flags are required to view performance or attributes of large files, beyond the regular file size commands (du, df, OneFS file explorer, and so on). For example, the following screenshot shows a 16 TiB file viewed from the OneFS file system explorer. You can access the file system explorer in the OneFS WebUI. Go to File System > File System Explorer and click View Property Details for the file system object of interest:
Here is a view of the same file from the OneFS CLI, reported both with and without protection overhead respectively:
# du -sh !$
18T largefile1.dat
# du -Ash l largefile1.dat
16T largefile1.dat
# ls -lsiah largefile1.dat
7721975847 19377986376 -rw-rw-rw- 1 root wheel 16T Apr 22 12:08 largefile1.dat
OneFS employs a unified permission model to ensure that authentication and data access control remains consistent, irrespective of the access protocol.
For more information about OneFS file permissions and access control, see the OneFS Authentication and Identity Management Guide.
For more granular file metadata information, the OneFS isi get CLI command provides several options to generate detailed output. Run without arguments, the command displays the data protection policy, stripe info (the number of disks that data and parity are written across), data access pattern, and write caching (coalescer) status.
# isi get largefile1.dat
POLICY LEVEL PERFORMANCE COAL FILE
+2d:1n 16+2 concurrency on largefile1.dat
The following table describes the basic output fields of the isi get command:
Attribute | Value | Description |
Policy | +2d:1n | Displays the data protection policy, in this case the ability to survive two drive failures or one complete node failure. The color indicates the protection status of the file (green is healthy). |
Level | 16+2 | Displays protection level or stripe information. This is the number of nodes a file’s data and parity blocks are written across, as illustrated in Figure 2. In this case, the file is striped across a total 18 nodes, containing 16 data blocks and 2 parity blocks. |
Performance | concurrency | Shows a file’s workflow-optimized layout strategy, which is essentially the number of drives per node a file is spread across. These strategies include:
OneFS also includes real-time adaptive prefetch, providing the optimal read performance for files with a recognizable access pattern, without any administrative intervention. |
Coal | on | Indicates whether the file is configured to use the OneFS coalescer, or write cache. This is an NVRAM-backed journal cache that buffers any pending writes to front-end files that have not been committed to disk. |
File | largefile1.dat | Displays the filename. |
For more information about file layout, optimization, and protection, see the OneFS Technical Overview white paper.
The isi get command offers additional flags and options for generating detailed contextual output, as shown in the following table
Command option | Description |
-a | Displays the hidden "." and ".." entries of each directory. |
-d | Displays the attributes of a directory instead of the contents. |
-g | Displays detailed information, including snapshot governance lists. |
-s | Displays the protection status using words instead of colors. |
-D | Displays more detailed information. |
-DD | Includes information about protection groups and security descriptor owners and groups. |
-DDC | Includes cyclic redundancy check (CRC) information. |
-L <LIN> | Displays information about the specified file or directory. Specify as a file or directory LIN. |
-O | Displays the logical overlay information and compressed block count when viewing a compressed file’s details. |
-R | Displays information about the subdirectories and files of the specified directories. |
For example, the following syntax reports the location of a file's inodes on the cluster.
# isi get -D largefile1.dat | grep inode
* IFS inode: [ 23,1,13439049728:8192, 30,1,127052275712:8192, 38,13,158235410432:8192 ]
This shows the three inode locations, the first of which (23,1,13439049728:8192) is on node 23, drive 1 (logical drive number).
To complement the isi get command, the OneFS CLI also includes the isi set utility.
# isi set -h
usage: isi set [-fFLnvrR] [-p <policy>] [-w <width>] [-c on|off|endurant_all|coal_only] [-g <restripe_goal>] [-e <encoding>] [-d <@r drives>] [-a default|streaming|random|disabled|custom{1..5}] [-l concurrency|streaming|random] [--nodepool <id|name>] [--packing on|off] [--strategy|-s avoid|metadata|metadata-write|data] [--mm-access|-A on|off] [--mm-packing on|off] [--mm-protection|-P on|off] file_or_lin ...
For more information about OneFS commands and feature configuration, see the OneFS Administration Guide.