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From: John Goerzen <jgoerzen@complete•org>
To: Sergey Matveev <stargrave@stargrave•org>
Cc: nncp-devel@lists.cypherpunks.ru
Subject: Re: NNCP discussion on comp.mail.uucp
Date: Tue, 05 Jan 2021 10:01:58 -0600	[thread overview]
Message-ID: <874kjv74p5.fsf@complete.org> (raw)
In-Reply-To: <X/SAm1s5dInAlPcN@stargrave.org>


On Tue, Jan 05 2021, Sergey Matveev wrote:

>>NNCP automatic tossing.
>>also had automatic calling
>
> Both of these looks like easy to add.

Sweet!

> Here I just want to add trivial comments for 
> https://floss.social/@jgoerzen/105499269925205743
>
> * Protection against Silent Data Corruption. Just want to 
> mention that
>   automatic self-healing (data correction) is performed also on 
>   a setup
>   with just single disk. "Data" blocks, by default has just 
>   single copy
>   and obviously they can not be repaired without redundancy. But 
>   metadata
>   blocks ("inodes", dataset/zvol descriptions, block pointers, 
>   and so on)
>   by default has copies=2 and physically they have two copies on 
>   the
>   disk. Very important metadata blocks (meta object set (MOS),
>   überblock) has copies=3. So metadata has (by default) 
>   redundancy and
>   can be repaired by reading the copy from another part of the 
>   disk

Very true indeed.

> * Built-in #compression with fast algorithms. Compression (at 
> least the
>   most simple rle one) should be enabled also because sparse
>   (zero-filled) blocks won't be allocated at all. If no 
>   compression is
>   enabled, then sparse files will be allocated and written to 
>   the disk

I did mention this one in the thread.  I personally use lz4 on all 
my zpools but I'm happy to see that zstd has been integrated now 
as well!

Should have better compression ratios AND better performance.

- John

      reply	other threads:[~2021-01-05 16:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-04  5:50 NNCP discussion on comp.mail.uucp John Goerzen
2021-01-04  8:36 ` Sergey Matveev
2021-01-04 17:46   ` John Goerzen
2021-01-05 15:07     ` Sergey Matveev
2021-01-05 16:01       ` John Goerzen [this message]