Weekend Learning: Exadata Database Machine and Exadata Storage Server versions

Have you ever asked yourself what the latest and greatest versions of Exadata components are?  So have I!  Well we are all in luck, as MOS document 888828.1 for the note "Exadata Database Machine and Exadata Storage Server Supported Versions" has all of the information you would ever need about Exadata versions!!

Exadata: Flash Cache Compression on X3 and X4 Storage Servers causing disk drive failures

Check what version of software you have on your Storage Servers immediately due to the bug listed in "(EX28) High risk of data loss on X3 or X4 Exadata storage when flash compression is enabled and running late 2015 or early 2016 software release" MOS article ID 2115005.1 which currently has NO solution!  There is a workaround listed, but that is turning off the Flash Cache Compression which will likely negatively affect the performance of your Exadata application and Oracle gives some great advice about proceeding with caution if you are planning upgrading!

Exadata: CellCLI "list activerequest" command can produce I/O hang in Storage Server

Do not miss out on applying the patch to resolve the issue described in the MOS article "(EX27) Database IO may hang when CellCLI command "list activerequest" is executed on an Exadata Storage Server" from note ID 2095255.1 so your system is not subject to this if you ever need to run the command in an Exadata machine!

Exadata: Oracle Enterprise Manager shows Management Server is DOWN but ping shows SUCCESS

With MOS document "EXADATA:OEM errors MS Status is DOWN and Ping Status is SUCCESS" from note ID 2112971.1 we learn that in Exadata Cell server software 12.1.2.2.0 the ipconf utility restarts the Management Server and that since ipconf runs with Exachk the MS gets restarts every time you run Exachk!  Seems like a problem huh?  The good news is that cellsrv does not actually go down, so there is no service interruption, but this is something you may need to know for your next patch application!

Exadata: InfiniBand may fail to send messages to cause I/O failures on Oracle VM

If you are running Exadata on Oracle VM, you need to look at the article "(EX26) Messages over the InfiniBand network may fail to send causing IO failures and hangs when using Exadata OVM with Exadata cell version 12.1.2.1.3" in My Oracle Support from note ID 2105407.1 as there is a pretty straightforward way to resolve this, even if it might not be the kind of solution you are looking for!

Weekend Learning: Whitepaper on Exadata monitoring with Enterprise Manager

Do not miss this whitepaper on Monitoring Exadata Storage Server Grids with Enterprise Manager from the Maximum Availability Architecture (MAA) team which has the entire step by step process and all the SQL you need to set up all of the conditions you need to alert on!

Exadata: Cellsrv process could crash on Storage Servers during cell-to-cell offload operations

If you are running Exadata platforms, do you know what version of software you have in your Storage Servers or what is running on your Grid Infrastructure?  Find out because the article "(DB35) Cellsrv process on storage servers may crash when performing a cell-to-cell offload operation" on My Oracle Support affects only certain combinations of software and note ID 2074393.1 details both of the patches that are needed to combat this situation!

Exadata disk drives in Storage Servers at risk for increased failures and performance issues

If you have Exadata in your environment I think you need to take a look at this newest MOS alert "(EX25) Disk drives in Exadata storage servers may experience increasing number of failures, unrecoverable media errors, confinement, and higher levels of read data latencies" via note ID 2073916.1 because several different versions of Exadata are affected by this issue with High Performance disk drives!

ASM: After disk comes online resync takes excessive amount of time

If you want to learn a bit more about ASM, especially if you have Exadata because it is affected as well, check out MOS article "ASM disk resync takes long time after disk online" from document ID 2061405.1 including the object GV$ASM_OPERATION which if you investigate on your system maybe you could develop alerts based on it!

Unable to communicate with ASM mirror copy if Exadata Storage Server is offline

Tonight the MOS document "(DB32) Bug 20217875 - When using normal redundancy Oracle is unable to perform I/O to an ASM mirror copy when an Exadata Storage Server is offline" from note 2057731.1 seems straightforward BUT shows how complicated ASM and Storage Servers are with even more reasons to be constantly monitoring these components!

Weekend Learning: OEM 12c FAQ for Exadata Virtualized Database Machine

If you are running a virtualized Exadata installation, and using OEM to monitor your systems, do not miss out on document ID 1967758.1 for the MOS article "Oracle Enterprise Manager 12c Exadata Management and Virtualized Exadata Database Machine FAQ" which details what versions are compatible with each other and how you need to be configuring the agent too!

Weekend Learning: Learning how to replace an Exadata Storage Server hard drive

This weekend learn both "How to Replace a Hard Drive in an Exadata Storage Server (Hard Failure)" and "How to Replace a Hard Drive in an Exadata Storage Server (Predictive Failure)" from MOS article IDs 1386147.1 and 1390836.1 respectively!

Exadata: New feature Exadata I/O Latency Capping causing ORA-27626 errors

Tonight we find out in My Oracle Support document 1925661.1 "ORA-27626: Exadata error : 2201 (IO cancelled due to slow/hung disk)" that the new feature Exadata I/O Latency Capping introduced with Exadata Storage Server 11.2.3.3.1 can actually interfere with I/O reads so learn what error messages you can prepare for in the log and trace files!

Weekend Learning: Critical Exadata issues

Did you know that Oracle keeps a list of "critical" issues for the Exadata platform?  It is true and MOS document "Exadata Critical Issues" is found from article ID 1270094.1 and might give you a lot of information this weekend about possible patches that you may need to apply to avoid potential problems!

Exadata: Cell corruption due to repeated CREATE and ALTER GRIDDISK CLI commands

Tonight you need to read "Oracle Exadata Storage Server Software 12.1.1.1.1 and Earlier may Cause Cell Disk Metadata Corruption if Many 'Create' or 'Alter' griddisk Commands are Run Over Time" via note 2029568.1 on My Oracle Support and then open up the referenced document inside to verify if you have disks which have this corruption so you can open up an SR with Oracle as this corruption cannot be resolved and you need to engage them immediately!!

Weekend Learning: Exadata security information

Do you run an Exadata installation?  Are you responsible for the security of said system?  Well then you might want to check out document "Responses to common Exadata security scan findings" on My Oracle Support note ID 1405320.1 and prepare for a lot of homework/investigation on your platform because this document is EXHAUSTIVE!

Exadata: Fixes needed for ASM File System due to data corruption

Fresh off the presses, and on the heels of my post about ASM allowing disks of 2TB, is article "Important Fixes required to implement Oracle Automatic Storage Management File System (ACFS) on Oracle Exadata Database Machine" found on My Oracle Support via document ID 2022172.1 which explains there are multiple concerns of data corruption in ASM including one affecting disks which are larger than 2TB!

Exadata: DB/ASM I/O request hangs if one cell has a problem

Very similar to my post on LCK0 hanging, there is a specific slant to the My Oracle Support document "Exadata Database Or ASM Instance Hung On IO Request When Single Cell Is Having Problem" via note ID 2002084.1 is worth checking out because there are some log entries we can look for to alert us about the next time we have this problem PLUS there is the bug that we can patch our system with too to prevent it!

ASM: ORA-15196 error encountered when disk is over 2TB

Always talking about getting to a better proactive position, My Oracle Support note 736891.1 gives us yet another angle to approach this from document "ORA-15196 WITH ASM DISKS LARGER THAN 2TB" because it affects many different versions of the database AND the Exadata platform!  There are patches available to prevent this from happening to you, and the aforementioned Exadata platform has patches available which allows a larger ASM disk!

Auto-Tier LUNs on Flash System may not be automatically released

If you have an Oracle Engineered System like Exadata or Exalogic, you may want to know how in some cases the Flash System doesn't get space released as found in MOS document "FS System: Deleting Auto-Tier LUNs May Not Increase Free Space for a Storage Domain" via article ID 2015849.1 so you can take a proactive look at your system to see if you suffer from this as well.