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Grex > Oldcoop > #380: Cyberspace Communications finances for November 2006 | |
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| Author |
Message |
| 8 new of 124 responses total. |
steve
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response 117 of 124:
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Feb 18 04:20 UTC 2007 |
Do you have documentation for it? Is it hardware only?
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maus
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response 118 of 124:
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Feb 18 05:26 UTC 2007 |
It is pure hardware RAID. I would have to check the make and model
(documentation should be on the mfc's webpage).
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maus
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response 119 of 124:
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Feb 18 06:01 UTC 2007 |
http://www.adaptec.com/en-US/products/scsi_tech/value/ASR-2230SLP/
Mirroring / and /usr on SCSI and /home and /var on Serial ATA would make
a very nice, well-split-up, performant, capacious system.
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steve
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response 120 of 124:
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Feb 18 07:28 UTC 2007 |
Hardware raid is definitely what we want. I will look at this.
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maus
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response 121 of 124:
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Mar 30 02:32 UTC 2007 |
Just curious, I have started seeing 10K RPM Serial ATA drives. Does the
increased rotational speed noticeably improve reading/writing of data?
Is the increase in data access speed a direct function of the rotational
velocity of the center spindle? Presuming it does, is this a real bottle
neck that we would face, or do 7200 RPM drives get to the data fast
enough that choke-points would be elsewhere in the system? I guess my
real question is "would we get benefit enough from 10K RPM drives to
justify the higher cost versus 7200 RPM drives?".
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nharmon
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response 122 of 124:
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Mar 30 11:20 UTC 2007 |
Yes, 10k RPM drives have higher I/O performance than slower spinning
drives. They also tend to have a lower capacity and are more expensive.
The rule of thumb I usually use to calculate I/O performance is:
RPM/100 = iops
That is, RPMs divided by 100 gives you I/Os per second. Of course, I
mainly deal with fiber channel drives so this may be way off. Your
arrangement is as important as your individual disk performance too. A
RAID 10 array is much faster than a RAID 5 array, but sacrifices a lot
of storage space.
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maus
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response 123 of 124:
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Mar 30 15:45 UTC 2007 |
Thanks for the rule of thumb and for confirming what I suspected about
RAID 1+0 vs RAID 5 performance (where I worked, we did not do RAID 5
except on rare occasion, and when we did, they didn't trust the grunts
to set it up or maintain it, so I usually only saw RAID 1, RAID 1+0 or
LVM/concatenated over multiple RAID 1 sets).
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ric
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response 124 of 124:
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May 5 03:51 UTC 2007 |
I've heard that these "perpendicular" drives at 7200 RPM are actually the
fastest for most situations.
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