6TB storage expansion
Introduction
56 instead of 50TB are now available for the bioinformatics cluster. The tasks required to realize this extra space are:
- rescan multipath, details: multipath WWID; 36000d3100051f800000000000000016e (on mpathd)
Tools
listing
multipath -l
will give a useful if not very understandable list of characteristics. Most important, the device: dm-6 is noted, i.e.
mpathd (36000d3100051f800000000000000016e) dm-6 COMPELNT,Compellent Vol size=50T features='1 queue_if_no_path' hwhandler='0' wp=rw `-+- policy='round-robin 0' prio=0 status=active |- 6:0:0:1 sdd 8:48 active undef running |- 7:0:1:1 sde 8:64 active undef running |- 6:0:1:1 sdg 8:96 active undef running `- 7:0:2:1 sdf 8:80 active undef running
configuration
/etc/multipath.conf
Doesn't really have much. The only actives are:
defaults {
user_friendly_names yes
}
blacklist {
wwid 3600605b006c5f11019eadc840e589ae9
wwid 3600605b006a1af8019ee9a2d1036bfa7
wwid 3600605b006a1af801b46c4773d54b7d4
}
= interpreter
There is also a interpreter available to query status and other things. To fire it up, type
multipathd -k
Procedure
The rescan operation is most definitely required. Both Red Hat and Ubuntu guides give the same method of doing this
# echo 1 > /sys/block/device_name/device/rescan
However, under /sys/block/dm-6, there is no device subdirectory, and, needless to say, no rescan file. Mind, this is for SCSI.
