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--- other:newppl:starting [2025/08/29 11:27] – [The home directory] Moved the "quota" section jypeter
+++ other:newppl:starting [2025/08/29 15:26] (current) – [Dealing with disk space] Finished rewriting the section jypeter
@@ Line 407: / Line 407: @@
   * **Quota**: ask your advisor
-==== Determining the space used by directories ====
+==== Dealing with disk space ====
-Your Linux environment may sometimes stop working correctly because you have exceeded the allowed quota on your disks (check your quotas with ''quota -s''). You can use the following command to get the size of all the directories and files in the current directory, sorted by size: ''du -sh * | sort -rh''
+<WRAP center round important 60%>
+Running out of disk space may have strange (and difficult to debug) side effects!
+</WRAP>
-<code> >cd /home/scratch01/johndoe
+**Disk space** on remote servers may sometimes seems infinite, but **is a limited resource**, especially if other users are not as careful as you!
-/home/scratch01/johndoe
- >du -sh * | sort -rh
+You should regularly check how much space you are using (''quota'', ''du''), and how much space is left (''df'')
+=== 'quota' command ===
+The ''quota -s'' command will tell you:
+  * If your disk usage (total size and/or number of files) is limited on some of the disks you use
+    * It is usually the case on the //home// directories (LSCE, spirit, computing centers, ...)
+  * How much disk space you are currently using on the disks with //quota// control
+The examples below shows how to display the current //quota// on the LSCE and spirit disks:
+  * //home// quota at LSCE
+    * <code> > quota -s
+Disk quotas for user johndoe (uid 0007):
+     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
+prolix3:/users/   4658M   4883M   4981M           23503       0       0</code>
+  * //home// quota on spiritx
+    * <code> $ quota -s
+Disk quotas for user janedoe (uid 0008):
+     Filesystem   space   quota   limit   grace   files   quota   limit   grace
+.17.3.169:/home
+K  32768M  33792M             339    400k    420k</code>
+  * The ''blocks'' or ''space'' column display your current usage of the disk where the quota is activated
+  * You can never go above the size displayed in the **//hard//** ''limit'' column
+  * You cannot stay more than 7 days above the **//soft//** limit displayed in the ''quota'' column!
+  * The ''grace'' column will display either:
+    * nothing: everything is fine!!
+    * ''N days'': you can still use this disk, but you have ''N days'' (decreasing from 7 days) to remove files and get back below the //soft// ''quota'' limit
+    * ''None'': you cannot write to this disk anymore, unless you remove files to get below the ''quota'' limit
+=== 'du' (disk usage) command ===
+You can use ''du -sh some_dir'' to determine the space used by ''some_dir'' (and all its sub-directories)
+Examples:
+  * At LSCE ''du -sh /home/users/johndoe'' will display the size of the //home// directory. It should be roughly the same value as the ''blocks'' column displayed by ''quota''
+  * You can use the following command to get the size of all the directories and files in the current directory, sorted by decreasing size:
+    * ''du -sh * | sort -rh''
+      * If you don't understand the //pipe// (''|'' character) above, read //Combining commands// in //[[#linux_unix|Useful Linux commands for working with (potentially big) text files (houchesa4_updated.pdf)]]//
+    * <code> > cd /home/scratch01/johndoe
+ > du -sh * | sort -rh
 M     GLAC1DHiceF26.nc
 M     dashboard
@@ Line 423: / Line 468: @@
 ...</code>
-FIXME Add something about ''df''
+=== 'df' command ===
+''df -h'' will display the total size of a disk, and how much space is left. A disk may be full, even if you have not reached your quota (because it is full of fools)
+Examples:
+  * <code> > df -h /home/users
+Filesystem      Size  Used Avail Use% Mounted on
+prolix3:/users  3.6T  2.1T  1.4T  60% /home/users</code>
+  * <code> >df -h /home/scratch01
+Filesystem                       Size  Used Avail Use% Mounted on
+prolix3.lsce.ipsl.fr:/scratch01   14T   13T  127G 100% /home/scratch01</code>
 ===== Which programs should you use? =====