AIX Server Specs

[huntinginvt]

Does anyone have some general guidelines for determining the size of a AIX server I would need to drive 8 LTO3 tape drives at an average rate of 200G/Hr.



I know in the Windows world a general rule of thumb has always been 1 CPU per 1 tape drive (both of the latest and greatest rev).



Thanks

 

[heada]

While I'm not using LTO-3, 3592 drives aren't that different when it comes to performance. I have a p520 (2-way, 1.5Ghz, 6GB of RAM, ESS disk) that backs up my SAP database (2TB Oracle via TDP for R/3) to 2 drives (4 drives total with sync-write enabled) in 5 hours over a 1Gb/s network. The bottleneck is the network (I run it at 1Gb/s for the entire 5 hours) While the backup is running, the server never gets above 30% utilized.



2TB in 5 hours across 2 drives is about 200GB an hour per drive (not including the sync-write)



-Aaron

 

[cheffern]

Hi there -

Are you asking how big your AIX server should be filesystem wise?

Or did Heada answer everything you needed?

I think I took the question in a little differently than he did...

 

[tsmtodd]

heada,

to rephrase, you are performing a TDP backup direct to tape over the network (not over the SAN to tape), taking 5 hours to backup up 2 TB, and utilizing <30% of the TSM server. Can I assume there are no other client sessions occuring at this time?

No other migrations/reclamations?

No other significant network activity?



Also, you indicate your server (assume you meant TSM server) is a p520, 2-way, blah blah, with ESS disk. I am assuming in the above backup scenario, the ESS disk really doesn't play into this config because the disk providing the data is on the other side of a network connection. I am curious how those disks are configured. How many spindles holds the data being backed up?

 

[heada]

The TSM Server is not performing any other major tasks while the TDP for SAP R/3 is running. There are a few small B/A clients, but nothing major. There might be an expiration and/or a reclamation running, but no backup stgpool or dbbackups. The TSM server has a smallish diskpool (300GB) in the ESS (model 800) and it's database (75GB) The SAP server is in the same ESS. The ESS has ~250 146GB drives in RAID5 configuration. It is running on average 8 SAP systems and several smaller systems.



We tried to use LAN-Free and got slightly faster backups (4 hours rather than 5) but since LAN-Free doesn't allow sync-write, we went back to LAN based backups. In the 5 hours, I am using 4 drives (2 for the primary, 2 for the copy)



I can give more details if you'd like.



-Aaron

 

[tsmtodd]

That's a very good reason to utilize LAN instead of LANFREE. Unfortunately, in our environment, we have so many other backup sessions running at the same time, off-loading to LANFREE frees up network and TSM server resources for other operations. Right now, we only have 100Mb network connections (on a B80), so LANFREE is a must. When we upgrade to new hardware, I will have to revisit the whole LAN vs LANFREE question.



When TDP SAP backs up, is it more like Oracle, in that you can specify backup file size maximums (going on what I have heard, cuz we haven't gotten those to work yet), or is it more like SQL, where if you have a 900GB database, and you stripe it to three tapes, you get three 300GB files?

 

[heada]

We are using 1Gb/s network connection and while the SAP backup is running, we use the full 100% of that network. We could cut the time down more by adding a second 1Gb/s network card and creating an etherchannel (2Gb/s total) but the cost of the cards and the costs of the ports don't justify the time savings yet.



The TDP for SAP R/3 is a beast unto itself. It is a combination of both the TDP-Oracle and TDP-MSSql. It will do null-block compression like Oracle (don't backup white spaces) but also stripping across tape drives like MSSql. It has the ability to will read where your data files are (on which disks), how many TSM sessions you have configured (2 for me) and how many data streams are configured (3 streams) and order the files so that no one disk is over loaded.



BKI1215I: Average transmission rate was 396.476 GB/h (112.776 MB/sec).

BKI1227I: Average compression factor was 1.24.

BKI0020I: End of program at: Mon May 22 12:16:06 2006 .

BKI0021I: Elapsed time: 05 h 45 min 21 sec .

BKI0024I: Return code is: 0.



(it ran a little long today)



-Aaron