Lustre 1.6 Operations Manual

F
Failback
Failout OST
Failover
FID
Fileset
FLDB
Flight Group
The failover process in which the default active server regains control over the
service.
An OST which is not expected to recover if it fails to answer client requests. A
failout OST can be administratively failed, thereby enabling clients to return
errors when accessing data on the failed OST without making additional
network requests.
The process by which a standby computer server system takes over for an
active computer server after a failure of the active node. Typically, the standby
computer server gains exclusive access to a shared storage device between the
two servers.
Lustre File Identifier. A collection of integers which uniquely identify a file or
object. The FID structure contains a sequence, identity and version number.
A group of files that are defined through a directory that represents a file
system’s start point.
FID Location Database. This database maps a sequence of FIDs to a server
which is managing the objects in the sequence.
Group or I/O transfer operations initiated in the OSC, which is simultaneously
going between two endpoints. Tuning the flight group size correctly leads to a
full pipe.
G
Glimpse callback
GNS
An RPC made by an OST or MDT to another system, usually a client, to
indicate to tthat an extent lock it is holding should be surrendered if it is not in
use. If the system is using the lock, then the system should report the object
size in the reply to the glimpse callback. Glimpses are introduced to optimize
the acquisition of file sizes.
Global Namespace. A GNS enables clients to access files without knowing their
location. It also enables an administrator to aggregate file storage across
distributed storage devices and manage it as a single file system.
Group Lock
Group upcall
Glossary-3