SUMMARY: 4.2GB drive with SunOS 4.1.4?

From: Jeff Mayzurk (
Date: Sat Mar 23 1996 - 16:19:55 CST

My original question:

> I just bought a Sun 4.2GB disk (the "UniPack," not a multi-disk pack)
> for use with an SS2 running 4.1.4. I was aware that SunOS couldn't use
> partitions larger than 2GB, but the documentation that came with the
> drive indicates that the OS doesn't like drives bigger than 2GB at all
> and thus it can't be used.
> Is there a workaround so that I can use this drive, even if I can only
> access 2GB? I don't want to upgrade this machine to Solaris quite yet.

The documentation that came with the disk clearly states: "Due to the
limitations of the operating system, 4-Gbyte disk drives can not be used
with the Solaris 1.x environment."

Shortly after sending the message to sun-managers, I decided that the
documentation *had* to be wrong, so I set up the disk with two 2.0 GB
partitions. Of course, it worked fine and I've had no problems whatsoever.
SunOS can't use partitions larger than 2.0 GB, but apparently it has no
problems with disks greater than 2 GB as long as they're partitioned

I received responses from many people, most of whom said "Just make two
partitions." A few people mentioned that I might have timeout problems when
formatting the drive, and that a patch was available to fix that problem.
Several people also mentioned Sun's Online Disk Suite, which allows for
partitions larger than 2 GB.

I was also told that I might have problems if I tried to use a large disk
for the root disk, but since I was installing this drive for another user
partition, I didn't have to opportunity to verify this.

>From Sean Ward <>:

>Hi Jeff. You can use the whole disk. It's just that the partitions can't be >larger than 4194304 (2^22) blocks. If you need partitions larger than that, >you'll have to either upgrade to Solaris, or use Sun's Online Disk Suite.

---- Raymond Wong <> writes:

>While it's possible that SunOS doesn't like that particular drive, there's >no reason you can't format most drives into 2 gig partitions and go. We >used both Seagate and Micropolis 9 gig drives, on SS2s and IPXs as well as >SS5s and 20s, running 4.1.3 as well as 4.1.4. You might have to modify >the kernel to adjust the format timeout value, or it might fail when formatting >the drive, but probably not. You will also need to create the right format.dat >entry, but I don't know the specs for that drive. You can actually fake up >the head cyl and sector numbers, remembering that you're trying to generate >3 factors that multiply out to the right block count. (using 512k blocks) >(This is often what the manufacturers do when they provide you with the >values, so don't feel too bad about some supposed performance penalty of >not being able to partition based on the actual physical geometry. That >hasn't been real performance issue in a few years.

---- >From Scott Pleitner <>:

>From what I understand, the only problem with SunOS and 4 gig disks is if >you want to install to it as your root disk. Apparently, suninstall just >doesn't understand that what you say when you partition the disk is what you >really want. We are using a 1gig disk as our system disk (on a Sparc 5) and >a 4.2Gig external for admin disk, /usr/local and source. Works fine.

---- Olga Aronov <> writes:

>You are right that SunOs can't use partitions bigger then 2GB >you can only see half of the drive under format when partitioning. > >Same goes for dkinfo . This is an putput of dkinfo for one of the 4GB drives: > >sd2: si: SCSI IOASIC controller at addr 1000, unit # 2 >3972 cylinders 19 heads 111 sectors/track >a: 63270 sectors (30 cyls) > starting cylinder 0 >b: 337440 sectors (160 cyls) > starting cylinder 30 >c: 4188474 sectors (1986 cyls) > starting cylinder 0 >d: 326895 sectors (155 cyls) > starting cylinder 190 >e: 126540 sectors (60 cyls) > starting cylinder 345 >f: 421800 sectors (200 cyls) > starting cylinder 405 >g: 2912529 sectors (1381 cyls) > starting cylinder 605 >h: 4188474 sectors (1986 cyls) > starting cylinder 1986 > >I just asuumed the drive was twice the number of sectors that it was >showng to be in c partition and it turned out to be right. >May be in your case it wont be twicw more but still should be >around the same number.

---- Larry J. Blunk <> writes:

> This is false. I'm using 4.2GB drives on several systems running >4.1.3_U1 and I'm using the whole disk. It is correct that each >filesystem can't be larger than 2GB. However, you can still >get Online DiskSuite 1.0 for SunOS 4.1.x which allows filesystems >larger than 2GB (plus it supports cool things like disk striping, >dynamic expansion of filesystems, RAID mirroring, etc.).


I'd like to thank everyone who responded to my question, including:

Mark Thomas <> Laurel Arthur <> Robert Bonomi <> Sean Ward <> "Marc L. Summers-SysAdmin" <> (Raymond Wong) Scott Pleitner <> Olga Aronov <> "Larry J. Blunk" <> (Steve Ehrhardt) Fedor Gnuchev <> Ilkka Virtanen <> Tim Carlson <> "Stephen J. Roznowski" <>

As it turns out I was able to answer the question myself, but sun-managers proved to be an invaluable source of information once again. Thanks.

-- Jeff Mayzurk Sierra On-Line, Inc. <>

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