Hi,


I've been (unsuccesfully) looking on the web for information on how long it
takes to synchronize logical volume copies.


i need to migrate data from an ESS -> Symmetrix DMX. san speed is 1 Gb.
servers are usually p650 or p690 (usually dual processor or 4-processor).
migration will be done on host level (by adding an lvm copy).

Can someone give me a rought figure about how long it would take per GB, or
point me to some information on the net so i can calculate myself ?


thx,


Tom.

Tom Van Overbeke wrote:

> I've been (unsuccesfully) looking on the web for information on how long it
> takes to synchronize logical volume copies.
>
>
> i need to migrate data from an ESS -> Symmetrix DMX. san speed is 1 Gb.
> servers are usually p650 or p690 (usually dual processor or 4-processor).
> migration will be done on host level (by adding an lvm copy).
>
> Can someone give me a rought figure about how long it would take per GB, or
> point me to some information on the net so i can calculate myself ?


It depends on a lot of factors.... On the speed of the source storage,
of the target storage, disk configuration, cache size, speed of the san,
number of connections through the san, so, the best way is to make some
kind of test, ideally with lvm sizes several times bigger than the cache
size of the targe system.

BC

Basically, the CPU power of your system does not matter at all.
lresynclv won't consume more than a handful of processor ticks while
active. The bottleneck to expect lies in the target storage system, on
a 1 Gbit SAN do not expect more than ~ 30 MB/s net throughput per
physical channel.
And there usually is a difference between the "official" rating of the
storage box and what it will be capable of in a given real situation.

KB

"Tom Van Overbeke" <tom.van.overbeke@pandora.be> wrote in message news:<c4rtns$2m301r$1@ID-172084.news.uni-berlin.de>...
> Hi,
>
>
> I've been (unsuccesfully) looking on the web for information on how long it
> takes to synchronize logical volume copies.
>
>
> i need to migrate data from an ESS -> Symmetrix DMX. san speed is 1 Gb.
> servers are usually p650 or p690 (usually dual processor or 4-processor).
> migration will be done on host level (by adding an lvm copy).
>
> Can someone give me a rought figure about how long it would take per GB, or
> point me to some information on the net so i can calculate myself ?
>
>
> thx,
>
>
> Tom.