[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [Linux-cluster] GFS, iSCSI, multipaths and RAID

Michael O'Sullivan wrote:
Hi Alex,

We wanted an iSCSI SAN that has highly available data, hence the need for 2 (or more storage devices) and a reliable storage network (omitted from the diagram). Many of the articles I have read for iSCSI don't address multipathing to the iSCSI devices, in our configuration iSCSI Disk 1 presented as /dev/sdc and /dev/sdd on each server (and iSCSI Disk 2 presented as /dev/sde and /dev/sdf), but it wan't clear how to let the servers know that the two iSCSI portals attached to the same target - thus I used mdadm. Also, I wanted to raid the iSCSI disks to make sure the data stays highly available - thus the second use of mdadm. Now we had a single iSCSI raid array spread over 2 (or more) devices which provides the iSCSI SAN. However, I wanted to make sure the servers did not try to access the same data simultaneously, so I used GFS to ensure correct use of the iSCSI SAN. If I understand correctly it seems like the multipathing and raiding may be possible in Red Hat Cluster Suite GFS without using iSCSI? Or to use iSCSI with some other software to ensure proper locking happens for the iSCSI raid array? I am reading the link you suggested to see what other people have done, but as always any suggestions, etc are more than welcome.

Check out dm-multipath (*not* md-multi-path) to see whether you can make use of it:

-- Wendy

[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]