Should I bother with a gvinum stripe when using a pair of SSDs?

[C. P. Ghost]

On Sat, Feb 16, 2013 at 3:47 PM, Jens Schweikhardt
<schweikh at schweikhardt.net> wrote:
> hello, world\n
>
> currently the only gvinum partition on my home system is a stripe for /home
> across two Velociraptor HDDs. I'm thinking of replacing the HDDs with a
> pair of SSDs. I was thinking of reducing complexity and in the migration
> possibly no longer use gvinum at all--one less thing to configure and worry
> about.
>
>  * Would gvinum striping bring any speed advantage with a pair of SSDs?
>  * Or am I hitting other limits so that striping SSDs is a waste anyway?
>  * Should I finally take the plunge and acquaint myself with ZFS?
>
> System has 4GB RAM in an ASUS P5Q3 Deluxe with SATA II. It appears to me
> that SATA II with 300MB/s is maxed out by a single SSD and striping it
> will not improve r/w throughput. Is my simplistic reasoning correct?

Jens,

as always it depends on what you're trying to achieve:
  - max speed / lower latency?
  - max storage?
  - max redundancy?
  - max run-time-to-data-loss?

Your choice of SSD probably means you'd like to reduce latency
and maximize data throughput.

Since you're going SSD, I suspect that maximizing total storage
capacity is definitely not your primary concern, right? In this case,
you probably won't need some space-saving RAID variants (like
RAID-5, RAID-Z, ...), therefore simple striping or mirroring would
be adequate.

However, striping puts your data at risk: lose one SSD, and the whole
volume becomes unusable. Mirroring would at least preserve some
redundancy.

Moreover, by NOT using ZFS, you're sacrificing the by-sector
checksumming that becomes rather important with SSD whose mode
of failure tends to favor single (silent!) sector corruption that may
go undetected for a while and grow worse over time. You may then
want a mirrored ZFS configuration if this is a concern.

Each solution has its pros and cons, and there are quite some
trade offs in there.

> Regards,
>
>         Jens
> --
> Jens Schweikhardt http://www.schweikhardt.net/
> SIGSIG -- signature too long (core dumped)

-cpghost.

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