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Hello, we have a
RedHat Avanced Server 2.1 with kernel version 2.4.9-e.12smp and we use lvm
version 1.0.3 (yes I know that the latest "one" version is 1.0.7). I
think that the version 2 is too much advanced for us. We have a very strange
problem with lvm, oracle and raw devices. If we take a logical volume manager
and test it with a simple dd we get: ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- time dd if=/dev/MKTP/strip32 of=/dev/null bs=512k
count=2048 real 0m13.394s ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- Ok, It works fine, we have 1Gbyte in 13 seconds. Now we bind this
logical volume to a raw device ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- raw /dev/MKTP/strip32 /dev/raw/raw15 ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- and we try with this: ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- time dd if=/dev/raw/raw15 of=/dev/null bs=512k
count=2048 real 0m14.828s ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- The same time, more
or less, all it's ok. Now we want use this
raw (raw15) with oracle. We create a oracle tablespace
put data into. We can access it through
oracle. We stop oracle. Now
we repeat the same dd: ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- time dd if=/dev/raw/raw15 of=/dev/null bs=512k count=2048 real 0m48.971s ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- Now we have 48
seconds, why?, The only one difference is the
tablespace creation. We try the same
process without lvm and we have the same good time in three cases. There are some
problem with lvm, raw and oracle? How can I avoid
this? Thanks in advanced Esta información es privada y confidencial y está dirigida únicamente a su destinatario. Si usted no es el destinatario original de este mensaje y por este medio pudo acceder a dicha información por favor elimine el mensaje y notifique el envío erróneo al remitente. La distribución o copia de este mensaje está estrictamente prohibida. Esta comunicación es sólo para propósitos de información y no debería ser considerada como una declaración oficial del Grupo gasNatural. La transmisión de e-mails no garantiza que el correo electrónico sea seguro. Por consiguiente, no manifestamos que esta información sea completa o precisa. Toda información está sujeta a alterarse sin previo aviso. Este Correo Electrónico ha sido procesado por nuestro sistema de Antivirus corporativo This information is private and confidential and intended for the recipient only. If you are not the intended recipient of this message you are hereby notified that any review it and notify the sender immediately, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an official statement from gasNatural Group. Email transmission cannot be guaranteed to be secure. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such.All information is subject to change without notice. This email has been scanned by our Antivirus system |
