Date: Fri, 2 Feb 2001 12:34:59 +1030 From: Greg Lehey <grog@lemis.com> To: Randy Primeaux <randy@Cloudfactory.ORG> Cc: Tony Landells <ahl@austclear.com.au>, freebsd-questions@FreeBSD.ORG Subject: Re: installing onto vinum Message-ID: <20010202123459.E82163@wantadilla.lemis.com> In-Reply-To: <200102020228.SAA04507@relay.ultimanet.com>; from randy@Cloudfactory.ORG on Thu, Feb 01, 2001 at 05:44:04PM -0800 References: <ahl@austclear.com.au> <200102020228.SAA04507@relay.ultimanet.com>
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On Thursday, 1 February 2001 at 17:44:04 -0800, Randy Primeaux wrote: > Tony, > It will be several hours before I can resume testing. In the > meantime, I have a question. > > Per `man 8 vinum`: > vinum uses the first 265 sectors on each partition for configuration in- > formation, so the maximum size of a subdisk is 265 sectors smaller than > the drive. > > My new interpretation is that I should reserve 265 sectors per subdisk > for configuration information. That is a misinterpretation. A partition corresponds to a drive, not a subdisk. > Following method one, where each subdisk overlays a partition, I > might choose to layout /var, /usr, and /home initially 265s larger, > then shrink each of them. You can't shrink a file system. Follow the instructions. > Part of my confusion stems from the fact that Greg's example > provided for two subdisks, and I chose to test with three. That doesn't make any difference. > Greg's example: >> >> 6. Carefully calculate the offsets and the lengths of the file >> systems. Create a Vinum configuration file something like this: >> >> drive root dev /dev/ad0s1d Oops, that's where this 'dev' comes from, is it? Sorry. As we've seen, it should be 'device'. >> volume usr >> plex org concat >> sd length 256m >> volume home >> plex org concat >> sd length 8g driveoffset 524553s >> >> The lengths and offsets need to be exact, of course. The best way >> to get offset and length is from the last 8 lines of disklabel >> ouput. > > My first interpretation for three subdisks: >> >> drive root dev /dev/ad4s1d >> volume var >> plex org concat >> sd length 256m driveoffset 265s >> volume usr >> plex org concat >> sd length 4g driveoffset 1048841s Where did you get this offset from? It should be 265s + 256m. 256m is 524288s, so it should be 524553, as shown above. As Tony and I both pointed out, though, it's best to go from the offsets and lengths in the disklabel output. >> volume home >> plex org concat >> sd length 79574302s driveoffset 8913161s This offset is correct, but since you've put usr.p0.s0 in the wrong place, it would overlap, and you won't be able to allocate it. > So on to my query. Using this example, should my second vinum subdisk > actually be 8388608s - 265s = 8388343s, where the original 4.2BSD > partition was 8388608s, thereby reserving 265s per each subdisk? No. > If not, then why? Because you can't shrink a file system. Your file systems must be exactly the same size and same place. You shrink swap instead. > Tony Landells writes: >>> I start out with the following disklabel: >>> >>> 8 partitions: >>> # size offset fstype [fsize bsize bps/cpg] >>> a: 524288 0 4.2BSD 1024 8192 16 # (Cyl. 0 - 32*) >>> b: 1048841 524288 swap # (Cyl. 32*- 97*) >>> c: 90060327 0 unused 0 0 # (Cyl. 0 - 5605*) >>> e: 524288 1573129 4.2BSD 1024 8192 16 # (Cyl. 97*- 130*) >>> f: 8388608 2097417 4.2BSD 1024 8192 16 # (Cyl. 130*- 652*) >>> g: 79574302 10486025 4.2BSD 1024 8192 16 # (Cyl. 652*- 5605*) >>> >>> >>> This is a test layout, in which I want / and swap to be static, and >>> /var, /usr, /home to be on vinum, to be mirrored on ad5 when I am >>> done. >>> >>> My intended layout is as such: >>> ad4s1a / 256M >>> ad4s1b swap 1048841 >>> ad4s1e /var 256M >>> ad4s1f /usr 4G >>> ad4s1g /home 79574302 >> >> Well, this is actually the way you allocated it originally (you haven't >> taken the vinum space out of swap here), but I know what you meant. (I >> only mention it for others following the example.) > > Yes, this example would be clearer if I showed this "Before" table, > and an "After" table. Yes, a good idea. >>> I booted a release CD, then operated the fixit floppy so I had vi >>> available without mounting /usr. I then changed the disklabel as follows. >> >> A safe way to go, though I found that you can do pretty much everything >> in single user mode after executing "mount -a". Really. > > Ok, Tony, I'll try that. No, don't, as I said in my message. > I feared hitting this error again, based upon a mis-interpretation > on my part: disklabel: ioctl DIOCWDINFO: open partition would move > or shrink Yes, you would. > As an aside, I had commented out partitions e, f, and g on my first > attempt. On my second attempt I left them intact, and added d:. That's the correct way to do it. Greg -- When replying to this message, please copy the original recipients. If you don't, I may ignore the reply. For more information, see http://www.lemis.com/questions.html Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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