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sheep - Distributed Block Storage System for QEMU

SHEEPDOG(8) System Manager's Manual SHEEPDOG(8)


sheep - Distributed Block Storage System for QEMU


sheep [options] [PATH]


sheep - Sheepdog is a distributed storage system for QEMU. It provides highly available block level storage volumes to virtual machines. Sheepdog supports advanced volume management features such as snapshot, cloning, and thin provisioning. The architecture of Sheepdog is fully symmetric; there is no central node such as a meta-data server.
The server daemon is called sheep(8). A command line utility is available via dog(8). QEMU virtual machines use the sheep daemon via a block driver available in qemu(1).


-b, --bindaddr
specify IP address of interface to listen on

$ sheep -b ...
This tries to teach sheep listen to NIC of

$ sheep -b ...
This tries to teach sheep listen to all the NICs available. It can be useful when you want sheep to response dog without specified address and port.
-c, --cluster
specify the cluster driver (default: corosync)
Available arguments:
local: use local driver
corosync: use corosync driver
zookeeper: use zookeeper driver, need extra arguments

zookeeper arguments: address-list,tiemout=value (default as 3000)

$ sheep -c zookeeper:IP1:PORT1,IP2:PORT2,IP3:PORT3,timeout=1000 ...
This tries to use 3 node zookeeper cluster, which can be reached by IP1:PORT1, IP2:PORT2, IP3:PORT3 to manage membership and broadcast message and set the timeout of node heartbeat as 1000 milliseconds
-D, --directio
use direct IO for backend store
-g, --gateway
make the progam run as a gateway mode
-h, --help
display this help and exit
-i, --ioaddr
use separate network card to handle IO requests (default: disabled)

$ sheep -i host=,port=7002 ...
This tries to add a dedicated IO NIC of to transfer data. If IO NIC is down, sheep will fallback to non IO NIC to transfer data.
-j, --journal
use jouranl file to log all the write operations. (default: disabled)
Available arguments:
size=: size of the journal in megabyes
dir=: path to the location of the journal (default: $STORE)
skip: if specified, skip the recovery at startup

$ sheep -j dir=/journal,size=1G
This tries to use /journal as the journal storage of the size 1G
-l, --log
specify the log level, the log directory and the log format(log level default: 6 [SDOG_INFO])

$ sheep -l dir=/var/log/,level=debug,format=server ...
Available arguments:
dir=: path to the location of sheep.log
level=: log level of sheep.log
format=: log format type
dst=: log destination type
if dir is not specified, use metastore directory
Available log levels:
Level Description
emerg system has failed and is unusable
alert action must be taken immediately
crit critical conditions
err error conditions
warning warning conditions
notice normal but significant conditions
info informational notices
debug debugging messages default log level is info
Available log format:
FormatType Description
default raw format
server raw format with timestamp
json json format
Available log destination:
DestinationType Description
default dedicated file in a directory used by sheep
syslog syslog of the system
stdout standard output
-n, --nosync
drop O_SYNC for write of backend
-p, --port
specify the TCP port on which to listen (default: 7000)
-P, --pidfile
create a pid file
-r, --http
enable http service. (default: disabled)
Available arguments:
host=: specify a host to communicate with http server (default: localhost)
port=: specify a port to communicate with http server (default: 8000)
swift: enable swift API Example:

$ sheep -r host=localhost,port=7001,swift ...
This tries to enable Swift API and use localhost:7001 to communicate with http server.
-u, --upgrade
upgrade to the latest data layout
-v, --version
show the version
Sheepdog daemon version 0.8.3
-w, --cache
enable object cache
Available arguments:
size=: size of the cache in megabyes
dir=: path to the location of the cache (default: $STORE/cache)
directio: use directio mode for cache IO, if not specified use buffered IO

$ sheep -w size=200G,dir=/my_ssd,directio ...
This tries to use /my_ssd as the cache storage with 200G allocted to the cache in directio mode
-y, --myaddr
specify the address advertised to other sheep

$ sheep -y ...
This tries to tell other nodes through what address they can talk to this sheep.
-z, --zone
specify the zone id (default: determined by listen address)

$ sheep -z 1 ...
This tries to set the zone ID of this sheep to 1 and sheepdog won't store more than one copy of any object into this same zone


Proper LSB systems will store sheepdog files in /var/lib/sheepdog. The init script uses this directory by default. The directory must be on a filesystem with xattr support. In the case of ext3, user_xattr should be added to the mount options.
mount -o remount,user_xattr /var/lib/sheepdog


sheepdog requires QEMU 0.13.z or later and Corosync 1.y.z.


/var/lib/sheepdog - Directory containing block storage information


dog(8), qemu(1), sheepfs(8), corosync_overview(8)


This software is developed by the sheepdog community which may be reached via mailing list at <>.
2017-03-05 Debian Sid