Date: Fri, 21 Nov 97 13:20:26 -0500 From: Mark Salyzyn <salyzyn_mark@dpt.com> To: freebsd-scsi@FreeBSD.ORG Subject: Re: DPT PM2144UWR Message-ID: <9711211820.AA29048@bohica.dpt.com>
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In article <Pine.LNX.3.95.971120180436.12632B-100000@linux1.americasnet.com>, you wrote: >1. If there IS a freebsd driver, where would I find it? Contact Simon Shapiro <shimon@i-connect.net> >2. Can you explain to me how the RAID 5 works on the DPT? For example, how >is recovery done upon failure of one of the drives? With a 2144UW you will need to shut down the system and run the DOS Storage Manager utility to initiate a rebuild. You could have an automatic rebuild start based on SMART status or drive failure to a hot spare in any case. However, the PM2144 hardware does not support the hot swap signal. A PM3334, will perform this duty automatically based on the hardware hot swap signal if implemented in the SCSI backplane. We have discussed a Storage Manager port with Simon, he is currently working on the passthrough code in the driver and hopefully we will be up to speed once that is done. The SCO emulation mode nothwithstanding ... >3. In RAID 5 mode, how does the diskspace work out? What I mean is how do >you calculate it? The smallest drive in the set (any more space on any other drive will simply be wasted) times [the number of drives minus one]. eg: a three drive RAID 5 will be double the size of the smallest drive. >It's easy for RAID 0 (add the drives), RAID 1 is the >total divided by the number of mirrors. But in RAID 5 what's the >calculation? If I use 3 2.5Gb drives, how much total space would I have? 5GB. Sincerely -- Mark Salyzyn
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