Unsolved
This post is more than 5 years old
2 Intern
•
225 Posts
0
738
April 17th, 2012 19:00
Redo log on VFCache Split-card configuration?
Greeting,
These days, I am reading some VFCache design documents, stating DAS part of VFCache Split-card configuration is good to rotating data, like Oracle Redo log etc.
As I remember, current BP recommend redo file on SAS devices with SP Write-cache backed.
Any comments?
Eddy
No Events found!
LouisLu
161 Posts
0
April 17th, 2012 20:00
Though I am not sure if right comments on, we also insisted PCI-based storage is entirely different.
Rather than a SCSI-connected hard disk drive, PCI Express SSD products often use specialized drivers to communicate using direct memory access (DMA) over the PCI bus. We always think this is game-changing in terms of I/O latency, enabling random read and write performance that's orders of magnitude faster than the quickest storage array.
I also recommend interesting blog from Chad -- VFCache Hello World. You can get more highlights.
dba_hba
63 Posts
0
April 18th, 2012 02:00
Eddie
There are three reason why putting your redo logs on local flash is not a good idea
1. It is not necessary or beneficial as explained to you here - redo log files have a predictable workload
https://community.emc.com/message/565585#565585
2. Potential Data loss if you lose your redo logs - what protection would you have for the DAS part of VFCache Split-card
https://community.emc.com/message/612845#612845
3. Restricted to single instance database only as the redo logs are on DAS
Each instances in an Oracle RAC database need to have access to all the redo logs for consistent recovery.