Added lustre description

lectures/file-and-data-systems/slides.qmd

@@ -158,13 +158,35 @@ from "Small Gods" by Terry Pratchett
 
 
 # Lustre as a parallel file system
-FLO
+
+*What if you are not the only one controlling the FS?*
+
+. . . 
+
+The file system becomes an independent system.
 
 ## File system via network
 
+* All nodes see the same set of files.
+* A set of central servers manages the file system.
+* All nodes accessing the lustre file system run local *clients*.
+
 ## Metadata and storage servers
+* The index is spread over a group of Metadata servers (MDS, 8 for work on levante).
+* The files are spread over another group (40 OSS / 160 OST on levante).
+* Every directory is tied to one MDS
+* A file is tied to one or more OSTs.
+* An OST contains many hard disks
+
+## The work file system of levante in context
+
+![](static/network-overview.png)
+
+
 
 ## Striping
+![[Zheng et al. 2020](https://doi.org/10.5194/gmd-13-3607-2020) CC-BY-4.0](static/gmd-13-3607-2020-f05-high-res.png){width=80%}
+
 
 
 # Shotgun buffet