Roch Bourbonnais wrote:
>
> Le 20 juin 07 à 04:59, Ian Collins a écrit :
>
>>>
>> I'm not sure why, but when I was testing various configurations with
>> bonnie++, 3 pairs of mirrors did give about 3x the random read
>> performance of a 6 disk raidz, but with 4 pairs, the random read
>> performance
Mario Goebbels wrote:
Because you have to read the entire stripe (which probably spans all the
disks) to verify the checksum.
Then I have a wrong idea of what a stripe is. I always thought it's the
interleave block size.
Nope. A stripe generally refers to the logical block as spread across
p
Le 20 juin 07 à 04:59, Ian Collins a écrit :
I'm not sure why, but when I was testing various configurations with
bonnie++, 3 pairs of mirrors did give about 3x the random read
performance of a 6 disk raidz, but with 4 pairs, the random read
performance dropped by 50%:
3x2
Blockread: 22
> Because you have to read the entire stripe (which probably spans all the
> disks) to verify the checksum.
Then I have a wrong idea of what a stripe is. I always thought it's the
interleave block size.
-mg
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> > A 6 disk raidz set is not optimal for random reads, since each disk in=20
> > the raidz set needs to be accessed to retrieve each item.
>
> I don't understand, if the file is contained within a single stripe, why
> would it need to access the other disks, if the checksum of the stripe
> is OK?
Mario Goebbels wrote:
>> A 6 disk raidz set is not optimal for random reads, since each disk in
>> the raidz set needs to be accessed to retrieve each item.
>>
>
> I don't understand, if the file is contained within a single stripe, why
> would it need to access the other disks, if the checks
> A 6 disk raidz set is not optimal for random reads, since each disk in
> the raidz set needs to be accessed to retrieve each item.
I don't understand, if the file is contained within a single stripe, why
would it need to access the other disks, if the checksum of the stripe
is OK? Also, why wou
OK... Is all this 3x; 6x potential performance boost still going to hold
true in a Single Controller scenario?
Hardware is x4100's (Solaris 10) w/ 6-disk raidz on external 3320's?
I seem to remember /(wait... checking Notes...) / correct... the ZFS
filesystem is < 50% capacity.
This info coul
Bart Smaalders wrote:
Ian Collins wrote:
Bart Smaalders wrote:
A 6 disk raidz set is not optimal for random reads, since each disk in
the raidz set needs to be accessed to retrieve each item. Note that if
the reads are single threaded, this doesn't apply. However, if multiple
reads are extant
Ian Collins wrote:
Bart Smaalders wrote:
michael T sedwick wrote:
Given a 1.6TB ZFS Z-Raid consisting 6 disks:
And a system that does an extreme amount of small /(<20K) /random
reads /(more than twice as many reads as writes) /
1) What performance gains, if any does Z-Raid offer over other RAI
Bart Smaalders wrote:
> michael T sedwick wrote:
>> Given a 1.6TB ZFS Z-Raid consisting 6 disks:
>> And a system that does an extreme amount of small /(<20K) /random
>> reads /(more than twice as many reads as writes) /
>>
>> 1) What performance gains, if any does Z-Raid offer over other RAID
>> or
michael T sedwick wrote:
Given a 1.6TB ZFS Z-Raid consisting 6 disks:
And a system that does an extreme amount of small /(<20K) /random reads
/(more than twice as many reads as writes) /
1) What performance gains, if any does Z-Raid offer over other RAID or
Large filesystem configurations?
michael T sedwick wrote:
Given a 1.6TB ZFS Z-Raid consisting 6 disks:
And a system that does an extreme amount of small /(<20K) /random reads
/(more than twice as many reads as writes) /
1) What performance gains, if any does Z-Raid offer over other RAID or
Large filesystem configurations?
Given a 1.6TB ZFS Z-Raid consisting 6 disks:
And a system that does an extreme amount of small /(<20K) /random reads
/(more than twice as many reads as writes) /
1) What performance gains, if any does Z-Raid offer over other RAID or
Large filesystem configurations?
2) What is any hindrance i
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