Evren Yurtesen wrote:
>>
>> Raid5 doesn't distribute disk activity - it puts the drives in
>> lockstep and is slower than a single drive, especially on small writes
>> where it has to do extra reads to re-compute parity on the existing data.
>
> I am confused, when a write is done the data is distributed in the disks
> depending on the stripe size you are using. When you start reading the
> file, you are reading from 5 different disks. So you get way better
> performance for sure on reads.
The stripe effect only comes into play on files large enough to span
them and not at all for directory/inode accesses which is most of what
you are doing. Meanwhile you have another head tied up checking the
parity and for writes of less than a block you have to read the existing
contents before the write to re-compute the parity.
--
Les Mikesell
[EMAIL PROTECTED]
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