From: Digest To: "OS/2GenAu Digest" Date: Mon, 14 Jul 2008 00:00:26 EST-10EDT,10,1,0,7200,4,1,0,7200,3600 Subject: [os2genau_digest] No. 1672 Reply-To: X-List-Unsubscribe: www.os2site.com/list/ ************************************************** Sunday 13 July 2008 Number 1672 ************************************************** Subjects for today 1 Re: IDE Raid : Chris Neeson" **= Email 1 ==========================** Date: Sun, 13 Jul 2008 19:05:09 +1000 From: "Chris Neeson" Subject: Re: IDE Raid fwiw, that one was a AHA 1200, Ed - simplistic PCI IDE, no slots for RAM, which got me thinking ( mmmm ). Yep, mirroring would be useful for upgrade time ( a lurch in faith ). My backup strategy for times like that is a disk copy - disks are cheap, particularly at the size I was using. I think that'll do for talking about it, I'll see what's going at the next swap meet I get to. Thanks, Chris Neeson On Thu, Jul 10, 2008 at 7:29 PM, Ed Durrant wrote: > Chris Neeson wrote: >> >> thanks for that, Ed. >> >> the adapter I saw was a simplistic Adaptec >> IDE ATA ( naturally, at a swap meet ). >> > > Well that's not a bad thing - what is the model number ?? >> >> My possibly naive assumption is that if the >> main drive stops working, so would OS/2, >> prompting a 'switch' to the mirror drive >> ( 'switch' being in quotes because that >> would be a physical changeover ) >> - that kind of monitoring being extremely >> basic analogue & empirical! >> >> > > With a mirrored drive, it's no so much a switch to another drive as a > stopping of writing to one of the two drives. They are normally written and > read in parrallel. But should one fail - you need to know about it to be > able to fix it. > >> The only gain there is that I wouldn't >> have to spend time on an install/rebuild >> & restore >> - but that would be a significant gain >> and saveing of time. >> >> > > Another use of Mirrored RAID is when you are planning a major software > upgrade that could go wrong. You disconnect one drive as this is an image > backup of the other drive. Perform the upgrade, if all is OK, you can then > reconnect the second drive and tell it to synchronise. If the update fails, > disconnect that drive reconnect the other drive and boot up - your system is > back as it was, then reconnect the "faulty image" drive and synchronise from > the good drive. > > Of course to do this other than from BIOS or bootable CD, you would need > utilities that run under OS/2. >> >> It sounds like it might be 'worth' trying >> in presumed moment of spare time >> ( though I'll check the current cards >> before going ahead ). >> >> > > Make sure you have a good backup before trying. >> >> Regards >> Chris >> >> > > Cheers/2 > > Ed. > > ----------------------------------------------------------------------------------