[EMAIL PROTECTED] wrote on 01/10/2007 05:16:33 PM:
> Hello Jason,
>
> Wednesday, January 10, 2007, 10:54:29 PM, you wrote:
>
> JJWW> Hi Kyle,
>
> JJWW> I think there was a lot of talk about this behavior on the RAIDZ2
vs.
> JJWW> RAID-10 thread. My understanding from that discussion was that
every
> JJWW> write stripes the block across all disks on a RAIDZ/Z2 group,
thereby
> JJWW> making writing the group no faster than writing to a single disk.
> JJWW> However reads are much faster, as all the disk are activated in the
> JJWW> read process.
>
> The opposite actually. Because of COW, writing (modifying as well)
> will give you up-to N-1 disks performance for raid-z1 and N-2 disks
> performance for
> raid-z2. Howeer reading can be slow in case of many small random reads
> as to read each fs block you've got to wait for all data disks in a
> group.
>
>
> JJWW> The default config on the X4500 we received recently was
RAIDZ-groups
> JJWW> of 6 disks (across the 6 controllers) striped together into one
large
> JJWW> zpool.
>
> However the problem with that config is lack of hot-spare.
> Of course it depends what you want (and there was no hot spare support
> in U2 which is os installed in factory so far).
>
Yeah, this kinda ticked me off, first thing I notice is that the thumper
that was on back order for 3 months waiting for U3 fixes was shipped with
U2 + patches. Called support to try to track down if U3 base was
installable with/without patches and spent 3 days of off and on calling to
get to someone who could find the info (sun's internal documentation was
locked down and unpublished to support at the time). 5 out of 6 support
engineers I talked to did not even realize that U3 was released (three
weeks after the fact). It also took 4 (long) calls to clarify that it did
infact need 220 power (at the time I ordered it was listed as 110, and it
shipped with 110 rated cables).
Long story short, I wiped and reinstalled with U3 and raidz2 with
hostspares like it should have had in the first place.
-Wade
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