Hi gurus!
Thanks to all who answered my question. See the answers below.
It looks like I asked the wrong question and put too much emphasis on OLDS.
I don't plan to stripe on the same spindle and I don't plan to have multiple
stripes on the same disk. And, of course, as far as I know, OLDS does not
stripe raw partitions(?). In fact, striping or concatenation is not the
issue here. Also, I don't need a vendor specific RAID solution.
All that I am looking for is a way to tell Solaris that a given disk has
more than 8 partitions. In my case these partitions are needed for various
purposes, only one of them being striping with OLDS. Other partitions are
used for other stuff, having nothing to do with OLDS or striping, and we need
lots of small ones, resulting in more than 8 partitions per disk. The reason
why we need lots of small partitions isn't an issue here.
So, my questions are:
1. Is there a way to have more than 8 partitions on a disk in Solaris,
either by using an other scheme or extending the existing one? Is there
an extension to Solaris which allows this? Does maybe Sun have an
unofficial way to do this?
2. If there is such a solution, would OLDS work with it, as OLDS assumes the
standard scheme with 8 partitions?
I hope my questions are clearer this time. TIA. I'll summarize.
- Tom
Here's the original question:
-----------------------------------------------------------------------------
>Sun's disk label or VTOC has a restriction of 8 partitions per disk. I
>suspect this has its origin a long time ago, when disks were still small
>and you seldom needed more than 8 partitions.
>
>Now I would like to split up some disks of 2 or 4GB into smaller partitions
>between 50 and 500MB, to be used as raw devices and striped with
>Online: Disksuite. Using such small partitions results in way more than 8
>partitions per disk. 16 partitions would already help a lot, but more would
>be even better.
>
>Is it possible to do this in general and such that it works with OLDS?
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>From kevin@uniq.com.au Wed Jul 12 03:04 MET 1995
[ Regarding "More than 8 partitions on a disk", felner@inf.ethz.ch writes on Jul 11: ]
> Sun's disk label or VTOC has a restriction of 8 partitions per disk. I
> suspect this has its origin a long time ago, when disks were still small
> and you seldom needed more than 8 partitions.
You still seldom need more than 8 partitions, which is why it was left
that way.
> Now I would like to split up some disks of 2 or 4GB into smaller partitions
> between 50 and 500MB, to be used as raw devices and striped with
> Online: Disksuite. Using such small partitions results in way more than 8
> partitions per disk. 16 partitions would already help a lot, but more would
> be even better.
You don't want to put stripes on the same disk, and putting multiple
stripes on a disk is not generally a good idea either - if you have more
than one stripe on a disk, and either stripe is busy, all you are guaranteeing
is that the head will move from one stripe to the other, which defeats
the whole idea of striping in the first place.
>
> Is it possible to do this in general and such that it works with OLDS?
What is it you are really trying to do - I realize that "optimize disk"
is the generic answer, but what is the application here, and what is
its pattern of access?
l & h,
kev
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>From w173@gf007e0.seag Wed Jul 12 02:30 MET 1995
Tom,
I didn't know ODS worked with raw partitions, if this works, please either
summarize or shoot me a quick email on how it worked...
Good Luck,
Al
-----------------------------------------------------------------------------
>From chris@boxhill.com Wed Jul 12 01:51 MET 1995
I work for a storage vendor and we see this problem all the time.
The solution we recommend for Solaris 2.x is to use the Veritas Volume
Manager (VxVM) instead of DiskSuite. VxVM provides concatenation, striping,
mirroring, RAID5, and very flexible management of a virtually unlimited
number of logical volumes.
For SunOS 4.1.x, we have software that can partition a disk into up to
250 partitions, but since normally provide this for use with our RAID5
products, it has not been tested with DiskSuite. It should work fine
provided that you stripe the disks together first and then partition the
resulting metadisks, but it may not work the other way around.
For more information, you can contact our sales department via e-mail to
sales@boxhill.com or at +1 212 989 4455.
Chris Maio
Box Hill Systems
-----------------------------------------------------------------------------
>From syd@dsinc.myxa.com Wed Jul 12 01:31 MET 1995
On Tue Jul 11 03:06:21 1995, Tomas Felner wrote,
> Now I would like to split up some disks of 2 or 4GB into smaller partitions
> between 50 and 500MB, to be used as raw devices and striped with
> Online: Disksuite.
Huh, want to slow things down. Striping a big disk into smaller
ones will just cause more long seeks. There is an advantage to a bigger
disk, in that it will attempt to keep files local, but still manage
less disks.
Striping on the same drive doesn't make sense. Striping across disks
does, but why worry about real small partitions.
-- Sydney S. Weinstein, CDP, CCP Former Elm Coordinator - Current 2.4PL24 Myxa Corporation Current Elm Coordinator: elm@myxa.com syd@Myxa.COM or dsinc!syd Voice: (215) 947-9900, FAX: (215) 938-0235 Welcome Page: http://www.myxa.com Elm WWW: http://www.myxa.com/elm.html----------------------------------------------------------------------------- >From goff@CAST.MsState.Edu Tue Jul 11 21:32 MET 1995
I think that if you check the OLDS documentation you will find that SUN does not recommend striping on partitions on the same spindle. This would defeat the purpose of striping. Actually they recommend using a separate controller for each disk in a stripe.
I may be wrong, but that is what I read about a year ago on OLDS 2.x.
Don Goff MSU-CAST Sys. Admin goff@cast.msstate.edu
//// (. .) +-------------------oOO-(_)-OOo----------------------------------+ | Tomas Felner (felner@inf.ethz.ch) -- System & DB Administrator | | Phone: +41-1-632-7253 Fax: +41-1-632-1172 | | Institute for Informationsystems, Database Group, IFW C 48.1 | | Haldeneggsteig 4, ETH Zentrum, CH - 8092 Zurich, Switzerland | +----------------------------------------------------------------+
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