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+====== FS: Lustre ======
+===== Characteristics =====
+<data_cdcl>
+name:Lustre
+</data_cdcl>
+===== Description =====
+The deployed file system is the Fujitsu Exabyte File System (FEFS), that is based on Lustre.
+Effectively, the system has two file systems, a file system local to the K-Computer with 11 PiB and a global file system with 30 PB [3].
+The local file system consists of 2592 OSS (5184 OSTs) and the global file system of 90 OSS (2880 OSTs); performance of the local file system is 3.2 TB/s and 1.4 TB/s for read and write, respectively [3]. This is much higher than the global file system which provides a throughput of 0.2 TB/s.
+A staging mechanism transfers data before/after a job is completed from the fast local storage to the global file system.
+The local file system can only be accessed from compute nodes and not from login or post-processing nodes.
+===== Measurement protocols =====
+==== Peak performance ====
+==== Sustained metadata performance ====
+The reported metadata rate has been measured using mdtest on 9000 nodes with 100 files/node. See [3, slide 34].
+Other benchmark runs have been conducted, for example, a mdtest on a variable number of clients shows how performance degraded with increase in clients and depends on the type of operation [2, slide 23].
+==== Sustained performance ====
+This was measured with the IOR benchmark using POSIX-I/O (90 OSS, 2880 OSTs).
+See [2] for a description.

Virtual Institute for I/O