Volume XtreemFs
dibuat pada MRC server (meta data & replica catalog server). Operasi volume
adalah sebagai berikut:
4.2 Volume Management
Like many other file
systems, XtreemFS supports the concept of volumes. A volume can be seen as a
container for files and directories with its own policy settings, e.g. for
access control and replication. Before being able to access an XtreemFS installation,
at least one volume needs to be set up. This section describes how to deal with
volumes in XtreemFS.
4.2.1 Creating Volumes
Volumes can be
created with the mkfs.xtreemfs command line utility. Please see mkfs.xtreemfs
--help or man mkfs.xtreemfs for a full list of options and usage.
When creating a
volume, you can specify the authorization policy (see Sec. 7.2)
with the option --access-control-policy (respectively -a). If not specified,
POSIX permissions/ACLs will be chosen by default. Unlike most other policies,
authorization policies cannot be changed afterwards.
In addition, it is
possible to set a default striping policy (see Sec. 7.4).
If no per-file or per-directory default striping policy overrides the volume's
default striping policy, the volume's policy is assigned to all newly created
files. If no volume policy is explicitly defined when creating a volume, a
RAID0 policy with a stripe size of 128kB and a width of 1 will be used as the
default policy.
A volume with the
default options (POSIX permission model, a stripe size of 128 kB and a stripe
width of 1 (i.e. all stripes will reside on the same OSD)) can be created
as follows:
$> mkfs.xtreemfs my-mrc-host.com/myVolume
Creating a volume
may require privileged access, which depends on whether an administrator
password is required by the MRC. To pass an administrator password, add
--admin_password <password> to the mkfs.xtreemfs command.
For a complete list
of parameters, please refer to mkfs.xtreemfs --help or the man mkfs.xtreemfs
man page.
4.2.2 Deleting Volumes
Volumes can be
deleted with the rmfs.xtreemfs tool. Deleting a volume implies that any data, i.e. all files and directories on the
volume are irrecoverably lost! Please see rmfs.xtreemfs --help or man
rmfs.xtreemfs for a full list of options and usage. Please also note that
rmfs.xtreemfs does not dispose of file contents on the OSD. To reclaim storage
space occupied by the volume, it is therefore necessary to either remove all
files from the volume before deleting it, or to run the cleanup tool (see
Section 5.2.2).
The volume myVolume
residing on the MRC my-mrc-host.com (listening at the default port) can
e.g. be deleted as follows:
$> rmfs.xtreemfs my-mrc-host.com/myVolume
Volume deletion is
restricted to volume owners and privileged users. Similar to mkfs.xtreemfs, an
administrator password can be specified if required.
4.2.3 Listing all Volumes
A list of all
volumes can be displayed with the lsfs.xtreemfs tool. All volumes hosted by the
MRC my-mrc-host.com (listening at the default port) can be listed as follows:
$> lsfs.xtreemfs my-mrc-host.com
The listing of
available volumes is restricted to volume owners and privileged users. Similar
to mkfs.xtreemfs, an administrator password can be specified if required.
No comments:
Post a Comment