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Envoyé: Jeudi 5 Juin 2014 22:56:38
Objet: [ceph-users] Minimal io block in rbd
Do for every read/write rbd read/write full block of data (4MB) or rbd can
read/wite part of block?
For example - I have a 500MB file (database) and need random read/write by
blocks about 1-10Kb.
Do for eve
Thanks.
> There's some prefetching and stuff, but the rbd library and RADOS storage are
> capable of issuing reads and writes in any size (well, down to the minimal
> size of the underlying physical disk).
> There are some scenarios where you will see it writing a lot more if you use
> layering
There's some prefetching and stuff, but the rbd library and RADOS storage
are capable of issuing reads and writes in any size (well, down to the
minimal size of the underlying physical disk).
There are some scenarios where you will see it writing a lot more if you
use layering -- promotion of data
I would think that rbd block are like stripes for RAID or blocks for hard
drives, even if you only need to read or write 1k, the full stripe has to be
read or write.
Cheers
--
Cédric Lemarchand
> Le 5 juin 2014 à 22:56, Timofey Koolin a écrit :
>
> Do for every read/write rbd read/write ful
Do for every read/write rbd read/write full block of data (4MB) or rbd can
read/wite part of block?
For example - I have a 500MB file (database) and need random read/write by
blocks about 1-10Kb.
Do for every read 1 Kb rbd will read 4MB from hdd?
for write?
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