Comments on: The Problem With I/O http://lonesysadmin.net/2006/07/25/the-problem-with-io/ im in ur data centrz patchin ur serverz Fri, 21 Nov 2008 22:53:38 +0000 http://wordpress.org/?v=2.6.3 By: Chris Adams http://lonesysadmin.net/2006/07/25/the-problem-with-io/#comment-4417 Chris Adams Tue, 25 Jul 2006 18:40:26 +0000 http://lonesysadmin.net/2006/07/24/the-problem-with-io/#comment-4417 I'm really looking forward to ZFS spreading for precisely this reason - I can't wait to get out of the micro-optimization business and ZFS has automatic hotspot balancing across the entire pool. You can basically wait for there to be a problem (pool-wide - completely avoiding the problems with small volumes being trivially spindle-limited) and add an extra/faster drive (which can be anything accessible by the system - you could buy some time to deal with a SCSI hotspot by tossing SAN storage at it or even a USB/firewire drive if you were really desperate). One of the developers likes to tell an anecdote about this flushed out some differences in the drive settings on a RAID enclosure which one of the beta testers used - the tester was wondering why one drive's activity LED flickered less often and learned that ZFS had noticed that it was slower than the others and wasn't using it for hot data. I’m really looking forward to ZFS spreading for precisely this reason - I can’t wait to get out of the micro-optimization business and ZFS has automatic hotspot balancing across the entire pool. You can basically wait for there to be a problem (pool-wide - completely avoiding the problems with small volumes being trivially spindle-limited) and add an extra/faster drive (which can be anything accessible by the system - you could buy some time to deal with a SCSI hotspot by tossing SAN storage at it or even a USB/firewire drive if you were really desperate).

One of the developers likes to tell an anecdote about this flushed out some differences in the drive settings on a RAID enclosure which one of the beta testers used - the tester was wondering why one drive’s activity LED flickered less often and learned that ZFS had noticed that it was slower than the others and wasn’t using it for hot data.

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