
Storage Management
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Titan SiliconServer
Important information about Quota Thresholds:
•
While quotas keep track of used disk space and number of files, neither file system
metadata nor snapshot files count towards the quota limits.
•
File sizes are computed based on the number of File System blocks used up. For
example, with a 32 KB File System block size, a 55 KB file will get reported as 64 KB.
•
Files with multiple hard links are included once only. A symbolic link adds the size of the
symbolic link file to a quota and not the size of the file to which it links.
Explicit, Default and File Systems Quotas
There are two types of File System Quotas:
1.
Explicit User/Group Quotas
A quota can be explicitly created to impose restrictions on an individual user or group,
defining a unique set of thresholds.
2.
Default User/Group Quotas
Quotas can be set automatically for all users and groups that do not have explicit
quotas. This is done by defining a set of thresholds (‘Quota Defaults’), which will be used
to create a quota automatically when a file is created or modified.
User Quota Defaults are a set of thresholds used to create a quota for a user the first
time that user saves a file in the File System.
Group Quota Defaults are a set of thresholds used to create a quota for a group the first
time a user in that group saves a file in the File System.
Initially, these Quota Defaults are set to zero (i.e. ‘not set’). When activity occurs in the
File System, although it is tracked, no quotas are created. Quota Defaults are defined by
setting at least one threshold to a non-zero value. Default Quotas will then be
automatically created. As soon as a set of Quota Defaults is defined in this way, a User
or Group Quota (as appropriate) will be created for the owner of the directory at the root
of the file system.
Severe
When the total size of all the files
reaches this value, a Severe alert is
issued.
When the total number of files
reaches this value, a Severe alert is
issued.
Reset
Alerts for Quotas are hysteresis based, so that alerts are disabled once a
certain threshold is crossed and an alert is issued. No other alerts are issued
until a reset level (threshold) is crossed, after space (or a number of files) is
recovered on disk. This means that the server does not continually issue alerts
stating that a threshold has been crossed. Quota alerting is re-enabled once
the used space (or number of files) drops a certain amount below the
threshold. The default value for this reset is 5% of the limit.