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LVM Tiered Storage - HSM on Linux (deprecated - please use lvmcache now)

Application for monitoring LVM volumes and moving blocks based on usage to faster and slower storage. In other words, Hierarchical Storage Manager utilizing LVM on Linux.

Dependencies:

lvm blktrace confuse debugfs (mounted in /sys/kernel/debug/)

Compiling:

make

Usage:

Run collector daemon:

MAKE SURE YOU HAVE debugfs MOUNTED!

./lvmtscd -f lvm-volume.lvmts -l /dev/lvm-group/lvm-volume

After some time you can output the stats using cat (by default it will output 100 most active blocks with blocks being logical extents):

./lvmtscat --LE lvm-volume.lvmts

To get 25 most active physical extents formatted as a parameter to pvmove, use following command:

./lvmtscat -b 25 --pvmove --VG VolumeGroupName --LV LogicalVolumeName lvm-volume.lvmts

Using lvmtsd

While collecting stats and using lvmtscat for looking at most active blocks gives much information, it doesn't do anything.

(it's a hack now, it will be made more user-friendly later)

First, edit doc/sample.conf file, the title of the volume section should have the same name as file created by lvmtscd, sans .lvmts extension, rest of the options is explained there.

Currently only one volume is supported, additional "volume" sections will be ignored.

First, run lvmtscd in the same dir as is doc/. Wait for it to write some statistics (if your system isn't active, wait at least half an hour, with busy system, 10min should suffice). If the file has gotten big, just run

./lvmtsd

It will move most active extents to fastest storage and then keep it updated according to rules in sample.conf

Now you may enjoy your hybrid storage!