SUMMARY: partitions under ADVfs: to be or not to be?
Thanks to John Stoffel, Steffen Kluge, alan_at_nabeth.cxo.dec.com, Saul
Tannenbaum, Phil Rand, Gyula Szokoly, Peter Stern, Martyn Johnson.
Majority recommended using the whole disk for a file domain to take
advantage of ADVfs flexibility and features.
>>>>> "Alex" == Alex Vorobiev <sasha_at_cs.swarthmore.edu> writes:
Alex> I am planning on using ADVfs.
Alex> One way would be to partition the disks and create filedomains
Alex> on each/some partitions.
Alex> Another way would be to create one filedomain on the overlap (c)
Alex> partition and later break it into filesets with quotas turned
Alex> on.
The second is the recommended method from DEC for both perfomance and
manageability. If you have one file domain with multiple filesets,
you don't have to worry as much about running out of space in one
fileset, while under-utilizing the other.
John F. Stoffel |
I chose to use the whole volume (and actually some partitions from
other disks as well) for the file domain and to create filesets within.
This gives true capacity sharing and minimizes wasted space for each
fileset (one major reason we switched to ADVFS).
Steffen Kluge
By restricting a domain to a partition, you ensure that
the space allocated to files in that domain will be
restricted to a particular area of the disk and won't
be all over. For some I/O loads this is a good way
to reduce the access time.
alan_at_nabeth.cxo.dec.com
Performance is supposed to be better when you use whole disks, but
we haven't really noticed it.
We started out using the first method, because it was similar to the way
we managed our ufs file systems, but we now like the second method better.
Especially now that fileset quotas are supported, we see little reason
to use multiple file domains. Right now, our preferred arrangement is
to have one 'system' domain for /usr, /var and maybe /tmp, and a 'data'
domain for user directories, mail spool directories, and other more volatile
directories. We're trying out advfs for our root partition, too, but
that's a special case because of limitations in advfs's root support.
Phil Rand
From: Peter Stern <peter_at_wiscpa.weizmann.ac.il>
Message-Id: <9601211123.AA26459_at_wiscpa.weizmann.ac.il>
Subject: Re: partitions on ADVfs: to be or not to be?
To: sasha_at_allspice.cs.swarthmore.edu
Date: Sun, 21 Jan 1996 13:23:47 +0200 (IST)
In-Reply-To: <199601191839.NAA12524_at_allspice.cs.swarthmore.edu> from "Alex Vorobiev" at Jan 19, 96 01:39:45 pm
X-Mailer: ELM [version 2.4 PL24]
Content-Type: text
The manual says that AdvFS gives best performance if the whole disk
is one partition. Certainly you have a lot more flexibility if you
use one big domain that you can divide into file sets, add other disk
volumes to, etc., than sticking to the UFS concept of deciding what
you disk partitions will be in advance.
Peter Stern
I am not aware of any major performance issues. In principle the "one domain"
approach ought to be better, because ADVfs has the opportunity to optimise
over the whole disc. But if you have two different partitions active, you are
guaranteeing that there will be a lot of seek activity between them.
Martyn Johnson
Received on Tue Jan 23 1996 - 21:29:57 NZDT