ReleaseNotes

Dear Users,

LizardFS 3.10.2 is out!
Featuring:

master: redesign in-memory representation of file system objects - at least 30% reduction in RAM usage
master: name storage: a possibility to keep all file names in BerkeleyDB, thus saving even more RAM
master: redesign of trash - increased performance, reduced RAM usage and CPU pressure
master: huge boost of responsiveness - lengthy operations split into asynchronous bits
master: OPERATIONS_DELAY* config entries, which allow postponing metadata operations on restart/disconnect
master, mount: make big snapshot, setgoal and settrashtime operations asynchronous to improve responsiveness
master: fix improper handling of endangered chunks
chunkserver: memory optimizations - at least 60% reduction in RAM usage
chunkserver: introduce smart descriptor management
tools: brand new `lizardfs` command, a unified replacement for mfs* tools with prompt and bash completion
all: various fixes and community requests

Detailed information:

Master’s memory and CPU
With 3.10.2, master is much more memory-efficient and responsive. RAM usage reduction was accomplished through redesigning the way it keeps metadata in memory, adding a possibility to keep some metadata in on-disk database (see USE_BDB_FOR_NAME_STORAGE in mfsmaster.cfg file for reference). Responsiveness was dramatically increased by recognizing all potentially lengthy operations and splitting their execution in smaller time bits. It applied to both in-master maintenance procedures and client’s requests like snapshotting/changing goal of very big directories.

`lizardfs` tool:
3.10.2 comes with new client tool: `lizardfs` utility. See `man lizardfs`,  `lizardfs -h` for details. Aside from known functionalities like setting/getting goals, making snapshots, etc. it comes with bash-like prompt and bash completion.
Examples:

lizardfs setgoal -r ec32 a/

lizardfs makesnapshot dira/ dirb/

lizardfs fileinfo a/*

lizardfs <<EOF
fileinfo a/*
setgoal -r 3 a
getgoal a/2
EOF

Future plans:
In next release, paths and build system is to be unified with the one from official Debian repository (e.g. configuration directory will officially become /etc/lizardfs). Also, more asynchronous client commands are coming (including awaited recursive-remove operation). A so called “minimal goal setting”, which will probably be named MIN_REDUNDANCY_LEVEL is being implemented as well. Finally, more news on native HA (μRaft) will appear.

Best,
Piotr Sarna
LizardFS Team