Re: [9fans] Fossil+Venti system memory requirements to be aware of?

[Steve Simon]

i agree absolutely with steve here, expanding venture arena by arena is easy, 
the ventibackup scripts show you how. even easier is to add arenas on a 
different disk partition to the same venti.

personally i wouldn't keep music or videos in venti. they don't compress well 
using the arithmetic techniques in venti and the de duplication is unlikely to 
be a win either. just put them on a separate mirrored partition.

i wrote a doc called venti rescue which details replacing disks and rebuilding 
your venti. it may be of help.

-Steve


> On 20 Oct 2016, at 19:41, Steven Stallion  wrote:
> 
>> On Thu, Oct 20, 2016 at 1:15 PM,   wrote:
>> Steven Stallion  writes:
>> 
>>> Sizing venti is also simple.
>> 
>> I disagree with this.  The best way to configure venti depends largely
>> on how you plan to use it.  I have multiple venti servers configured for
>> different uses.  For example, I keep my DVD images on a different venti
>> server than I do for smaller, more frequently-used files such as mail.
> 
> see venti(8); there's plenty of advice on configuring your store with
> rough estimations for an initial conf file. Once you decide your
> geometry, it's trivial to extend the number of arenas in the store,
> just remember to reindex.
> 
>> I don't know that to be true.  If the source and destination volumes are
>> the same size, yes, it's easy to just dd the arenas.  But if you're
>> relocating to a smaller/larger partition, what would be an easy way to
>> do that?
> 
> see venti-backup(8).

Re: [9fans] Fossil+Venti system memory requirements to be aware of?

[Steve Simon]

> On 20 Oct 2016, at 19:41, Steven Stallion  wrote:
> 
>> On Thu, Oct 20, 2016 at 1:15 PM,   wrote:
>> Steven Stallion  writes:
>> 
>>> Sizing venti is also simple.
>> 
>> I disagree with this.  The best way to configure venti depends largely
>> on how you plan to use it.  I have multiple venti servers configured for
>> different uses.  For example, I keep my DVD images on a different venti
>> server than I do for smaller, more frequently-used files such as mail.
> 
> see venti(8); there's plenty of advice on configuring your store with
> rough estimations for an initial conf file. Once you decide your
> geometry, it's trivial to extend the number of arenas in the store,
> just remember to reindex.
> 
>> I don't know that to be true.  If the source and destination volumes are
>> the same size, yes, it's easy to just dd the arenas.  But if you're
>> relocating to a smaller/larger partition, what would be an easy way to
>> do that?
> 
> see venti-backup(8).

Re: [9fans] Fossil+Venti system memory requirements to be aware of?

[Steven Stallion]

On Thu, Oct 20, 2016 at 1:15 PM,   wrote:
> Steven Stallion  writes:
>
>> Sizing venti is also simple.
>
> I disagree with this.  The best way to configure venti depends largely
> on how you plan to use it.  I have multiple venti servers configured for
> different uses.  For example, I keep my DVD images on a different venti
> server than I do for smaller, more frequently-used files such as mail.

see venti(8); there's plenty of advice on configuring your store with
rough estimations for an initial conf file. Once you decide your
geometry, it's trivial to extend the number of arenas in the store,
just remember to reindex.

> I don't know that to be true.  If the source and destination volumes are
> the same size, yes, it's easy to just dd the arenas.  But if you're
> relocating to a smaller/larger partition, what would be an easy way to
> do that?

see venti-backup(8).

Re: [9fans] Fossil+Venti system memory requirements to be aware of?

[cigar562hfsp952fans]

"James A. Robinson"  writes:

> Anyone able to tell me whether or not there are
> disk size limits I should beware of given a limited
> amount of system memory in a file server?

Although there have been some replies on this thread, none of them have
really yet directly answered your question.  When setting up a venti
server, the size of the Bloom filter has a big impact on memory usage
and performance.  Details about computing Bloom filter size can be found
in the docs.  You could set up venti on a machine with very little
memory if you're happy with it constantly going out to check the index.

Re: [9fans] Fossil+Venti system memory requirements to be aware of?

[cigar562hfsp952fans]

Steven Stallion  writes:

> Sizing venti is also simple.

I disagree with this.  The best way to configure venti depends largely
on how you plan to use it.  I have multiple venti servers configured for
different uses.  For example, I keep my DVD images on a different venti
server than I do for smaller, more frequently-used files such as mail.

Choosing a good arena size isn't trivial, either.  If you ever plan to
back-up your venti to optical media, 640 MiB is the ideal arena size.
There is a lot of math behind that determination, but its implications
can be summarized as follows: Whether you're burning to standard CD-Rs,
extended CD-Rs, DVDs, DVD DL, Blu-ray, flash media, or to another HDD,
the amount of "wasted" space will never exceed 5% of the media's total
capacity.  In other words, the archvie will always be a minimum of 95%
space-efficient.  (Caveat: when burning 640 MiB arenas to optical media,
you may need to turn off Joliet/Rock Rigde extensions in order to make
the ISO image fit.)

> and it's also relatively trivial to move your data between stores.

I don't know that to be true.  If the source and destination volumes are
the same size, yes, it's easy to just dd the arenas.  But if you're
relocating to a smaller/larger partition, what would be an easy way to
do that?