linux equivalent to Solaris SVM diskset
- From: js <noone@xxxxxxxxx>
- Date: Sun, 04 Dec 2005 11:49:24 +1100
In Solaris, you have the concept of a diskset ... which is basically a group
of LUNs / disks that can be shared between hosts.
With Solaris 8 and 9, the diskset can only be one "owner" of the diskset.
Other hosts configured for the same diskset can take "ownership" of the
diskset if the current owner releases ownership ... or you take ownership
forcibly from the current owner.
With Solaris 10, you can have "multi-owner" disksets, where 2 or more hosts
read and write to the same disks in the diskset. Never used this option
yet, and I can't even begin to understand how they do it ( since I always
thought that you need to have the SCSI reservation ID, which prevents the
multi-owner concept ).
Thus, this shared-disk subsystem provides the foundation for things such as
failover, clustering, etc...
Currently, I only use manual failover from one host to the other host, where
2 hosts connect to the same external disk array x 2.
What I am after for is an equivalent in linux.
I know there is GFS, GPFS, etc.... but these are shared filesystems. What I
needed are shared devices, because I need shared raw partitions.
I also do need some shared filesystems, but I presume that once you have
shared raw partitions, you can just use ext3 on top of it.
What I am envisioning at the minimum are 2 hosts, 2 external disk ararys.
The disks in the disk array will be striped ( RAID 0 ). This will be done on
the firmware on the array.
The 2 external disk arrays needs to be mirrored ( RAID 1 ). Linux software
mirroring will do this.
I am just missing the part where I can share devices.