This shows you the differences between two versions of the page.
Next revision | Previous revision Next revision Both sides next revision | ||
cluster:100 [2011/03/27 21:03] hmeij created |
cluster:100 [2011/03/28 13:20] hmeij |
||
---|---|---|---|
Line 3: | Line 3: | ||
==== Quotas ==== | ==== Quotas ==== | ||
+ | |||
+ | On 03/25/2011 quotas have been enabled on cluster greentail. | ||
+ | |||
+ | Here is what was put in place, and will mature over time. But first, it is important to understand: | ||
+ | |||
+ | * A quota is not disk space allocated for you, as in reserved. | ||
+ | * Reason for quotas: to avoid /home from filling up by a runaway process, and constrain large users from growing beyond arbitrary thresholds. | ||
+ | |||
+ | The quotas fall into two tiers: the sliding tier and the custom tier. | ||
+ | |||
+ | * In the sliding tier, when you reach your soft limit, notify HPC admins and your quota will slide to the next strata (<100G, <250G, <500G, <750G). Once you reach the last strata, and you still need more disk space, you enter the custom tier. | ||
+ | * In the custom tier, we set a quota after agreeing on size and availability of disk space, plus 100G. Then you are on your own. | ||
+ | |||
+ | We urge all users to consider archiving data and files off the cluster disk array. | ||
+ | |||
+ | How to find my quota? You can find your quota levels and current usage as follows. | ||
+ | |||
+ | * The hard block limit is the absolute maximum amount of disk space that a user can use. Once this limit is reached, no additional disk space can be used. Writes to disks will fail. | ||
+ | * The soft block limit defines the maximum amount of disk space that can be used. Unlike the hard limit, the soft limit can be exceeded for a certain amount of time. That time is known as the grace period. | ||
+ | * The grace period is globally set for 7 days. | ||
+ | |||
+ | < | ||
+ | |||
+ | [hmeij@greentail ~]$ quota -v hmeij | ||
+ | |||
+ | Disk quotas for user hmeij (uid 8216): | ||
+ | | ||
+ | / | ||
+ | 1227284 | ||
+ | |||
+ | </ | ||
+ | |||
==== Notes ==== | ==== Notes ==== | ||
+ | |||
+ | * Implementation | ||
+ | * add usrquota, | ||
+ | * log everybody out or reboot (quota error on boot, not initialized yet) | ||
+ | * quotaoff | ||
+ | * quotacheck -cvug /home (file system goes read only! 10TB of whcih 6TB used, took 3 hours) | ||
+ | * set default user quota and propagate to all users | ||
+ | * set custom quotas for other users | ||
+ | * wrap adduser | ||
+ | * quotaon | ||
+ | * group quota numbers do not add up !? | ||
+ | |||
+ | * Array | ||
+ | * 48 TB minus 4 global spares | ||
+ | * after formatting 36 TB available | ||
+ | * /home 10, /snapshots 10, /sanscratch 5 after that leaves 11 TB | ||
+ | * snapshots holds base plus deltas hence needs to be somewhere between 1-2x base | ||
+ | * so if we wanted to increase home, we could not use sanscratch (is anybody using it?) | ||
+ | * if we do not backup, then ... questions for later | ||
* Links | * Links | ||
Line 10: | Line 61: | ||
* [[http:// | * [[http:// | ||
* [[http:// | * [[http:// | ||
- | * [[http:// | + | * [[http:// |
\\ | \\ | ||
**[[cluster: | **[[cluster: | ||