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

Warren Block wblock at wonkity.com
Sat Feb 16 16:13:23 UTC 2013


On Sat, 16 Feb 2013, Jens Schweikhardt 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?

That would be 300M per disk, potentially up to 600M total.  It would 
have to be benchmarked to see if there is any real improvement.

It had never occurred to me that ZFS could do RAID0, but apparently it 
can.  Some ZFS safety features might make it a little less dangerous 
than RAID0 on gvinum.  ZFS has some overhead and might not be as fast as 
gvinum.

One larger SSD plus an add-in SATA III controller would be simpler.  The 
bigger SSDs are frequently faster than the smaller ones due to internal 
striping layouts, so it's like getting a RAID0 setup anyway.

I "slow mirror" SSDs with a backup hard drive via cron and rsync.


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