Date: Wed, 13 Jun 2007 03:56:29 -0600 From: Scott Long <scottl@samsco.org> To: Nico -telmich- Schottelius <nico-freebsd-scsi@schottelius.org> Cc: freebsd-scsi@freebsd.org Subject: Re: Migrating from adaptec 39320 to lsi u320-2 Message-ID: <466FBF4D.3070106@samsco.org> In-Reply-To: <20070613084904.GD27749@schottelius.org> References: <20070613072837.GC27749@schottelius.org> <466FA0DD.1000604@samsco.org> <20070613084904.GD27749@schottelius.org>
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Nico -telmich- Schottelius wrote: > Scott Long [Wed, Jun 13, 2007 at 01:46:37AM -0600]: >> Nico -telmich- Schottelius wrote: >>> Hello guys! >>> >>> I replaced the 39320 in our dell sc1425 with a lsi logic u320-2. >> This is a MegaRAID controller, yes? > > Yes > >>> [...] >> It sounds like you've purchased a RAID controller, not a SCSI >> controller. I know that statement sounds foolish. However, a RAID >> controller is not meant to provide direct, raw access of the disk to >> the OS, it's meant to provide access to storage volumes that are backed >> by disks. The controller is going put management/configuration metadata >> onto certain sectors of the disk, and it's going to hide those sectors >> from the OS. That's simply how it works. > > Ok, I thought one could use the raid controller in 'dumb' mode: like > creating two raid0 arrays with one member. > And then using those two arrays under freebsd to bind them with gmirror. > > Don't you think that it is possible to shrink the filesystem on the > disks, move the gmirror data some bytes to the front and then have spare > bytes for the size the lsi uses for metadata? There are no tools for shrinking UFS that I know of. Moving the gmirror metadata would require that it be regenerated with a new calculated disk size. You could probably dump the contents of each filesystem to tape, recreate your arrays and mirrors from scratch, and then restore the dump. Scott
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