Filesystem types

[JensD]

I've read up on the various documentation offered by IBM on what is recommended when trying to optimize things such as DISK type files, database directory etc etc etc.

However I am a bit surprised when it comes to recommendations regarding the chosen filesystem.

On the "Configuring Linux systems for disk performance" page (available at http://www.ibm.com/support/knowledgecenter/SSGSG7_7.1.1/com.ibm.itsm.perf.doc/t_perf_diskos_lnx.html) for the latest version of TSM available in the different versions (7.1.1 at this time), there is no mention of xfs and ext4 is almost considered "cutting edge" when reading the parts about storage pools.

When I look at recommendations for DB2 (https://www.ibm.com/support/knowled...ibm.db2.luw.admin.dbobj.doc/doc/r0056470.html) it was also first with v11+ that ext4 and even xfs became recommended - even v10.5 only had ext3.

Should I stick with ext4 for the DB2 parts of my new TSM v7 install on RHEL7 or go with xfs?
Should I ignore ext4 for storage pools and go with xfs too?
What stories or contemplations do you have from your own experience?

At the moment I am torn between using ext4 for everything related to DB2 (DB2 data directory, DB2 back directory, active log, active log mirror, archive log and archive log failover) and just going with xfs since it's default on RHEL7. Redhat seems to thing xfs is stable enough, but it seems like IBM still hasn't discovered it as an option..

For all STGPs I've already chosen to go with xfs - I cannot see a reason why I should not do so, even if IBM doesn't exactly recommend it..

 

[JensD]

Oh yes, I forgot to add this:

In the latest "IBM Spectrum Protect Blueprints" (v2.3) available at https://www.ibm.com/developerworks/... Manager/page/IBM Spectrum Protect Blueprints from April 1st, the "Blueprint for Linux x86" PDF mentions this on page 30 (38 in the actual PDF) under "Configure file systems for Tivoli Storage":

You must format file systems for each of the disk LUNs that the Tivoli Storage
Manager server will use. Format database-related file systems with ext4 or ext3.
Format storage pool LUNS with xfs.

.. and this is with the following prerequisites listed earlier in the same PDF:

* Red Hat Enterprise Linux x86-64, Version 7.1 or later
* [...] Storage Manager server V7.1 and later. To use directory-container storage pools
with inline data deduplication, you must install Tivoli Storage Manager V7.1.3 or
later.

 

[moon-buddy]

XFS and EXT4 are not officially supported thus I would not use these.

I tried installing 7.1.3 on XFS and, needless to say, had problems along the way. I even had PMRs opened and the only way to resolve this is reinstall with EXT3

 

[JensD]

Alas.. seems like I'll stick with ext4 for everything DB2 related and xfs for STGPs.

Thanks!

 

[JensD]

A follow question:

Does anyone have experience with using noatime when mounting DB2 directories to avoid excessive wear and tear when all directories are backed by SSDs?

I have been unable to find anything that weighs either for or against using noatime..

 

[JensD]

Follow up (or reference for others) after finding the right combination of terms to search for..

Tivoli Storage Manager server-supported file systems:
http://www-01.ibm.com/support/docview.wss?uid=swg21902417