In (modest) praise of Solaris DiskSuite
Now that I've worked with it for a while, I have to admit that Solaris DiskSuite is actually pretty neat. Since I've been dissatisfied with most of the other bits of Solaris, this came as something of a surprise to me.
(Solaris DiskSuite is Sun's version of software RAID, for those who have not encountered it before.)
There's nothing revolutionary in DiskSuite; it's just well integrated. This is really the advantage of a single-source vendor; Linux can probably duplicate almost all of DiskSuite's functionality, but you'd have to glue all the bits together, which is a pain.
(I say 'almost all' because Linux is not as smart as DiskSuite for peeling parts of mirrors off and then putting them back on. Linux forces a full mirror resync, while DiskSuite appears to keep track of what got written to while the submirror was offline and only updates that, which is much faster.)
This is partly a social advantage more than a technical one, because Sun is in a position to say internally 'we will do it this way'. By contrast, if the Linux software RAID people (for example) picked one of the various high availability systems to work with it would be a pretty divisive thing and unlikely to be well accepted. This is good for forcing all of the Linux HA systems to compete on technical appeal instead of how well they can sell themselves to someone in a position to pick a winner, but bad for getting a generally accepted and well integrated HA system for NFS fileserving.
I've found that one advantage of getting significantly involved with DiskSuite is that it gives me a better appreciation of the good and bad bits of both DiskSuite and Linux software RAID. Using multiple implementations of the same idea is useful to give you a deeper view of it, and this time has been no exception.
(This is not to say that DiskSuite is perfect. There's certainly a number of Linux software RAID features that I really wish DiskSuite had stolen, and that's not even touching LVM.)
All of this does make me really curious about Solaris 10's ZFS stuff, which is presumably (in part) the follow-on to DiskSuite. Unfortunately we're unlikely to run Solaris 10 any time soon, so I will probably not get to play around with it in the near future.