Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

due to inactivity or low temperatures, and relocating them to higher tiers in the

storage hierarchy.

The following XML snippet illustrates relocating files from tier2 volumes to

tier1 when the activity level against them increases.

<FROM>

</SOURCE>

</FROM>

<TO>

</DESTINATION>

</TO>

<WHEN>

</IOTEMP>

</WHEN>

</RELOCATE>

The <RELOCATE> statement specifies that files on tier2 volumes whose I/O

temperature as calculated using the number of bytes read is above 5 over a 2-day

period are to be relocated to tier1 volumes. Bytes written to the file during the

period of interest are not part of this calculation.

Using I/O temperature rather than a binary indicator of activity as a criterion for

file relocation gives administrators a granular level of control over automated

file relocation that can be used to attune policies to application requirements. For

example, specifying a large value in the <PERIOD> element of an upward relocation

statement prevents files from being relocated unless I/O activity against them is

sustained. Alternatively, specifying a high temperature and a short period tends

to relocate files based on short-term intensity of I/O activity against them.

I/O temperature and access temperature utilize the sqlite3 database for building

a temporary table indexed on an inode. This temporary table is used to filter files

based on I/O temperature and access temperature. The temporary table is stored

in the database file .__fsppadm_fcliotemp.db, which resides in the lost+found

directory of the mount point.

Administering SmartTier

Calculating I/O temperature and access temperature

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