On Jul 10, 2010, at 5:46 AM, Erik Trimble <erik.trim...@oracle.com> wrote:
> On 7/10/2010 1:14 AM, Graham McArdle wrote: >>> Instead, create "Single Disk" arrays for each disk. >>> >> I have a question related to this but with a different controller: If I'm >> using a RAID controller to provide non-RAID single-disk volumes, do I still >> lose out on the hardware-independence advantage of software RAID that I >> would get from a basic non-RAID HBA? >> In other words, if the controller dies, would I still need an identical >> controller to recognise the formatting of 'single disk volumes', or is more >> 'standardised' than the typical proprietary implementations of hardware RAID >> that makes it impossible to switch controllers on hardware RAID? >> > > Yep. You're screwed. :-) > > single-disk volumes are still RAID volumes to the controller, so they'll have > the extra controller-specific bits on them. You'll need an identical > controller (or, possibly, just one from the same OEM) to replace a broken > controller with. > > Even in JBOD mode, I wouldn't trust a RAID controller to not write > proprietary bits onto the disks. It's one of the big reasons to chose a HBA > and not a RAID controller. Not always, my Dell PERC with the drives set as single disk RAID0 disks, I was able to successfully import the pool on a regular LSI SAS (non-RAID) controller. The only change the PERC made was to coerce the disk size down 128MB, so left 128MB unused at the end of the drive, which would mean new disks would be slightly bigger. -Ross _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
