QOS(4) QOS(4)
NAME
qos - Xsan File System FSM QoS Central Config File
SYNOPSIS
/Library/Preferences/Xsan/*_rvio.opt
DESCRIPTION
The Xsan File System qos config file defines the bandwidth reservation
for non-rtio (rvio) on certain clients from a central place, i.e. the
fsm server. The allocated rvio bandwidth is used for non-rtio IOs on
the client. The config file has the name of the designated volume's
name appended by "_rvio.opt". So if the volume is "default", the QoS
config file will be "default_rvio.opt". If this file does not exist,
there will be no rvio bandwidth reservation for any client.
non-rtio reservation (rvio) provides a second priority bandwidth reser-
vation mechanism for certain clients, while rtio request has the high-
est priority and will be satisfied first. All rvio requests share the
remaining bandwidth after rtio requests are satisfied. If all rvio
requests cannot be satisfied, then each rvio client is allocated the
bandwidth directly proportional to its request amount. With dynamic
changes of rtio requests, the allocated rvio bandwidths for clients are
dynamically adjusted.
SYNTAX
A QoS central config file has multiple lines, each line defines the
rvio reservation for a client. If a client has multiple IP addresses,
the rvio reservation should be defined for each ip address.
The format of an line in QoS central config file is:
<host> <bw-type> <sg=yy>[,sg=yy]
<host> is the client host name. This can be the IP address (either V4
or V6), host name or FQDN of the client. Note: the host name should be
able to be resolved (converted to a valid IP address) by the fsm
server.
The <bw-type> is the type of bandwidth to be specified. Two types
exists:
qosios the bandwidth unit is IOs per second
qosmb the bandwidth unit is mega bytes per second
If "qosios" is used, you may also append multiplier suffix to the
amount of bandwidth:
Suffix Name Multiplier
------ ---- ----------
K kilo 1,024
M mega 1,048,576
The <sg=yy> defines the bandwidth on the designated storage pool. sg is
the designated storage pool, yy is the reserved bandwidth. You can only
reserve bandwidth on __stripe_groups__ whose QoS parameters have been
configured in the volume config file. There are three ways to specify a
storage pool:
* the wildcard for storage pool, applies to all storage pool
sgname the name of a storage pool
sgnum the number of a storage pool, storage pool starts from 0.
Lines that contain white space only or that contain the comment token
as the first non-white space character are ignored. An example on how
to configure QoS central config file can be found:
/System/Library/Filesystems/acfs.fs/Contents/examples/rvio.example
FILES
/Library/Preferences/Xsan/*_rvio.opt
SEE ALSO
cvfs(1), snfs_config(5), fsm(8), mount(1)
Xsan File System July 2008 QOS(4)
Mac OS X 10.9.1 - Generated Sun Jan 5 15:15:50 CST 2014