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Re: else or Debian (Re: ZFS performance (was: Re: deduplicating file systems: VDO with Debian?))



On Thu, 2022-11-10 at 20:32 -0500, Dan Ritter wrote:
> Linux-Fan wrote: 
> 
> 
> [...]
> * RAID 5 and 6 restoration incurs additional stress on the other
>   disks in the RAID which makes it more likely that one of them
>   will fail. The advantage of RAID 6 is that it can then recover
>   from that...

Disks are always being stressed when used, and they're being stessed as well
when other types of RAID arrays than 5 or 6 are being rebuild.  And is there
evidence that disks fail *because* RAID arrays are being rebuild or would they
have failed anyway when stressed?

> * RAID 10 gets you better read performance in terms of both
>   throughput and IOPS relative to the same number of disks in
>   RAID 5 or 6. Most disk activity is reading.
> 

and it requires more disks for the same capacity

For disks used for backups, most activity is writing.  That goes for some other
purposes as well.

> [...]
> 
>  The power of open source software is that we can make
> opportunities open to people with small budgets that are
> otherwise reserved for people with big budgets.

That's only one advantage.

> Most of the computers in my house have one disk. If I value any
> data on that disk,

Then you don't use only one disk but redundancy.  There's also your time and
nerves you might value.

>  I back it up to the server, which has 4 4TB
> disks in ZFS RAID10. If a disk fails in that, I know I can
> survive that and replace it within 24 hours for a reasonable
> amount of money -- rather more reasonable in the last few
> months.

How do you get a new suitable disk within 24 hours?  For reasonable amounts of
money?  Disk prices keep changing all the time.

Backups are no substitute for redundancy.


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