SSD vs Flash based SANs – Oracle DB I/O comparison

-

SSD vs Flash based SANs – I/O comparison
During a storage migration project from SSD based SAN  and Flash based SAN,  we have performed following tests to compare the I/O performance. On each of the tests it was observed flash was outperforming the SSD SAN on various magnitudes.
This is not a comprehensive load test, but this acted more as a POC to go ahead with the flash implementation.

1.      File Creation using “dd” command

10 G File Creation
root@prt51fin2 # date;time dd if=/dev/zero of=/xiv-test1/xivtest count=10240        bs=1048576;date
Wed Jan 24 17:20:32 IST 2018
10240+0 records in
10240+0 records out

real    1m16.735s
user    0m0.043s
sys     0m8.783s
Wed Jan 24 17:21:49 IST 2018
root@prt51fin2 #



----------------------------------------------------------------------------------



root@prt51fin2 # date;time dd if=/dev/zero of=/flash-test/flashtest count=10240 bs=1048576;date
Wed Jan 24 17:23:35 IST 2018
10240+0 records in
10240+0 records out

real    0m20.672s
user    0m0.037s
sys     0m7.034s
Wed Jan 24 17:23:56 IST 2018
root@prt51fin2 #





20 G File Creation


root@prt51fin2 # date;time dd if=/dev/zero of=/xiv-test1/xivtest count=20480 bs=1048576;date
Wed Jan 24 17:27:00 IST 2018
20480+0 records in
20480+0 records out

real    2m24.082s
user    0m0.086s
sys     0m16.639s
Wed Jan 24 17:29:24 IST 2018
root@prt51fin2 #

----------------------------------------------------------------------------------

root@prt51fin2 # date;time dd if=/dev/zero of=/flash-test/flashtest count=20480 bs=1048576;date
Wed Jan 24 17:30:09 IST 2018
20480+0 records in
20480+0 records out

real    0m43.506s
user    0m0.072s
sys     0m14.124s
Wed Jan 24 17:30:52 IST 2018






2.      asm io commands




ASM IO operations were performed
via data file creations and the times were compared. During the ASM data file
creation disk service times were also monitored where the flash had ~5X less
service times again.








SSD










Flash









3.     
Orion test 



Finally, Orion test was performed
on SSD and Flash disks. With small I/O operations flash was outperforming SSD by significant margin. Orion results are attached here with.



SSD_Flash Orion test results









































Comments











Post a Comment






























Popular posts from this blog









ORA-16433: The database or pluggable database must be opened in read/write 






-














Image







ORA-16433 is an error returned when a database cannot be opened. This can be a result of multiple conditions including, The inconsistency of the database Physical corruption Loss of dependent files or access issues etc.. More often than not the solution is to recover from available backups, but there can be situations where backups are not available, specially on UAT or Test setups. Although not the ideal scenario, in this type of situation you might want to open the databases even with inconsistency.      In Comes --> _ALLOW_RESETLOGS_CORRUPTION First, if you are in a position to use _ALLOW_RESETLOGS_CORRUPTION=TRUE, that means it has to be a critical moment, and when you come across more ora- errors while you are trying to reopen the databsae, that can be annoying.  Note - _ALLOW_RESETLOGS_CORRUPTION=TRUE must only be used after Oracle support confirmation as a last resort. Also make sure to take cold backup before proceeding. Basic steps to be followed to resolve ORA 16433 after 








Read more










Oracle Multitenant - Create new service for PDB using DBMS_SERVICE






-














Image







   When an Oracle PDB is created it starts up a default service with the PDB name. For direct connections to    PDB this service can be used. But there are situations where new service name is required in PDB level, common example is after a PDB restoration/clone, in order to enable application connections without changes in connection string. Setting service_names parameter in PDB level is not possible hence it is not an option in multitenant setup.    How to create a new PDB service on Oracle 12C  Check the current services, here only the default service is running,      SQL> show pdbs;      CON_ID CON_NAME            OPEN MODE RESTRICTED    ---------- ------------------------------ ---------- ----------         3 NFACTORPDB           READ WRITE NO    SQL> select service_id, name, pdb from dba_Services;    SERVICE_ID NAME                   PDB    ---------- ---------------------------------------- ----------         7 nfactorpdb                NFACTORPDB    SQL>      Create 








Read more










Wait for unread message on broadcast channel - Blocking Sessions






-














Image







  What is Wait for unread message on broadcast channel wait event?  Wait for unread message on broadcast channel is a wait event where source destination communication is involved and the database is waiting for a reply from remote party.  Mostly this wait is seen related to data pump export (expdp) or import (impdp) operations.  Although categorized in idle wait class "Wait for unread message on broadcast channel" can become the blocking session for some other sessions.  Common causes for stuck sessions waiting on this wait event includes,   Broken databases links, where remote database is not responding.  Abnormally killed remote processes causing the sessions to wait.      When a session is waiting on "Wait for unread message on broadcast channel" it can become a blocking session for dependent sessions. Most probably these sessions will be waiting on "library cache pin" or related concurrency wait events. The blocking_session column of (g)v$session view








Read more