DotHill – Linux Device Mapper Multipath “How To” for Storage Revision 4
DotHill – Copyright 2009 11
no_path_retry
(only for RHEL4)
n is the number of retries until disable
queuing (queues till n number of
polling), or fail means immediate
failure (no queuing), queue means
never stop queuing (queue forever or
until the path comes alive)
• n (>0)
• fail
• queue
features
(only for SLES)
Sets the SuSE DM-MP driver to queue
I/O if no path is available. This is
recommended for SuSE 9.0.
• “1 queue_if_no_path”
Each of these attributes can be set either on a per-device basis for a single storage resource, on a
per-storage array basis of for all the storage resources presented by one model of storage array,
or for all storage resources seen by the system. The file is divided into four sections: system
defaults, blacklisted devices, per-storage array settings, and per-device settings. Settings made in
the per- device section apply only to the device specified in that section; settings made in the
per-storage array section apply to all devices presented by that model of storage array. Devices
in the blacklisted devices section are excluded from DM-MP control.
To determine the attributes of a multipath device, the blacklisted devices section is checked first.
If the device does not match an entry in the blacklist, then the per-device section is checked. If
there is no match there, then the per-storage array section is checked. Devices that do not match
entries in any of the previous three sections inherit the settings in the system defaults section.
In addition to a template file,
/etc/multipath.conf, the DM-MP package installs three other
versions of this configuration file:
• /usr/share/doc/device-mapper-multipath-0.4.5/multipath.conf.annotated
This file contains detailed descriptions of each of the parameters that can be used. (A copy of
this file is included as an appendix to this document for easy reference.)
• /usr/share/doc/device-mapper-multipath-0.4.5/multipath.conf.defaults
This file contains the settings that are compiled into the code. Running DM-MP without a
configuration file is the same as using the
multipath.conf.defaults file.
• /usr/share/doc/device-mapper-multipath-0.4.5/multipath.conf.synthetic.
This file contains the same entries as the template file that is placed into the /etc directory
during package installation
.
6.3 Multipath.conf (Additional Detail)
6.3.1 System defaults (defaults)
Devices that are not specified in one of the other three sections of the file inherit their properties
from the defaults section. The following settings are compiled into the code and are also show in
the multipath.conf.defaults file:
(48 strony)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Komentarze do niniejszej Instrukcji