On Wed, Jan 27, 2016 at 10:05 AM, Ryder, Michael S <
michael_s.ryder AT roche DOT com> wrote:

> Are you using TDP for Virtual Environments for block-level image backups?
> Do you have deduplication enabled?  Both features will grind away at your
> log filesystems.  In my case enabling those features tripled the size of
> the DB and the rate and size at which the log space is used.
>
> At the same time TSM is trying to stream data to  your primary disk-based
> storage pool, it is also trying to update its log files.
>

No DeDup and currently no TSMVE but looking at it


> When they both
> exist on the same physical drives, those drives will be taxed in trying to
> perform both operations - even with a single array controller it would be
> more efficient to have spindles dedicated to log/db filesystems.  Perhaps
> consider replacing your OS/DB/App drives with a mirror of large SSDs, and
> put the log files there, too.  Even if they are all on the same array
> controller, the speed improvement for the DBs and logs should lower the
> latency of operations concerning your RAID5 array.
>
> What filesystem?  ext3 or ext4?  If you're on ext3, I understand from IBM's
> docs that as of RHEL6.x ext4 is suitable and provides some performance
> improvement.  Did you follow the docs and disable RHEL's read-ahead
> caching?  If so, you may want to consider enabling it.
>

Everything is ext4.  Will discuss the read-ahead caching with the OS guy.


>
> Wait... why would you be able to go with RAID10?  You would go from a RAID5
> array of (6) 6TB drives of *30TB*... to a RAID10 array of (6) 6TB drives of
> *18TB* - I thought you said you couldn't slice and dice this anymore?
>

This was mentioned at the last meeting to discuss the performance issues
since we are discussing completely wiping/rebuilding the box due to the
questionable state of the OS.

>
> Sadly - if you don't have any other flexibility, I think you will have to
> live with your performance, because your priority was for capacity and
> unfortunately you can't have both in these harddrives.
>

A correction.  The server is a R730xd. Dell specs say the drives are "6TB
7.2K RPM NLSAS 6Gbps 512e 3.5in Hot-plug".  The 2-1TB are the same specs
other than being 2.5in.

The box came with 6-6TB drives and 4-slots empty. We moved 6-600GB SAS
drives into the empty slots and created another RAID5 array of ~1.7TB for
additional storage. Sounds like maybe we should move the DB/logs/archlogs
to it?




--
*Zoltan Forray*
TSM Software & Hardware Administrator
Xymon Monitor Administrator
Virginia Commonwealth University
UCC/Office of Technology Services
www.ucc.vcu.edu
zforray AT vcu DOT edu - 804-828-4807
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