Performance tuning 1

[angelshark]

Hello,


I’m running NetWorker 6.0.2 and I would like to have faster backups/restores. What would be the best way to improve performance considering the server configuration below?

System: Sun Ultra Enterprise 450
OS: Sun Solaris 2.6
CPUs: 2 x UltraSPARC-II 300 MHz
RAM: 512
Swap: 1 GB
Network: 100 Mbps Full Duplex
Backup device: StorageTek L20 (2 drives and 18 slots)
Parallelism settings: 16 on the server and 2 on all the clients.


Thanks for your help.

 

[Chapter11]

How many clients do you have?

My first instinct is to do something about your network speed. I run about 35 clients, and I use a 2 gig pipe to my dedicated backup network (two 1-gigabit ethernet combined with etherchannel). 100M is fine for a client, but not the server side if you're dealing with lots of clients.

 

[angelshark]

I currently have 28 clients but we’ll be adding a significant number of clients in the near future.

All clients are on 100MB Full Duplex.

Note: compression is enabled in the backup device but disabled in NetWorker.

Thanks.

 

[jimbopalmer]

the network will be much less congested if the clients do compression in Networker I tried to remain child-like, all I acheived was childish.

 

[angelshark]

I have run some backups with compression enabled but I haven’t noticed any difference in performance.

Thanks for your post.

 

[Chapter11]

28 clients over a single 100M pipe? If you have any monitoring tools for that pipe, look at 'em one night while your backups are going on. I stand by my suggestion of increasing bandwidth between your server and switch.

 

[TDun]

Start from basics, does each client have 100MBit lan connection?
What throughput are you seeing on the tapes (e.g. 11Mb/s)?
What scsi controllers are the tape drives attached to(wide, ultrawide...)?
What times do the backups kick off? Are they staggered or altogether?
Draw yourself a flow of the clietns start and backup times
| ********
client | ******
|_______********__________________
time
to see what overlaps you have.

 

[angelshark]

All clients have a 100Mbit LAN connection.

The average throughput that I usually see on the Tape Library is of 5Mb/s for each tape drive.

The Tape Library is attached to 3 standard SCSI controllers.

I have 5 savegroups that run during the week at 22:40, 00:05, 01:00, 01:30 and 02:00. In the weekend I have 4 savegroups that run at 15:00 and 21:00 on Saturday and at 09:00 and 16:00 on Sunday. The savegroups that run during the week occasionally overlap each other by an average of 15 minutes.

Thanks for your help.

 

[jimbopalmer]

100 Mbps is 12 MBps so 2 5MBps streaams indicates you are about filling the Network, compressing at the client may help a little. If it is still 5 MBps when only one tape is running, then that is the top speed of the tape, if the tape goes faster when only one is running then the network is a bottle neck. (my DLT 7000 tapes peak at 5.5 MBps, I can still get that peak with two running, so my 100 Mbps NIC is not a serious bottle neck, I compress at the client) If I add any more drives, I need to go to a gig NIC. I tried to remain child-like, all I acheived was childish.

 

[TDun]

Ok, so for most of the backup you are writing only 2 threads. I can't say for definite on LTo, but on DLT, 4 or more is moreefficient for writing.
As you are already near network limits, then you may want to consider upping the client parallelism to 4 (assuming you have 4 savesets, if not, this is not worth doing).

 

[angelshark]

Each tape device in the Library has been set to manage 4 target sessions, therefore there are up to 8 streams that are saved concurrently. Each client has at least 4 savesets. Should the client parallelism be set to 4 or it won’t make any different if left at 2?

Thanks for your replies.

 

[TDun]

Look at the monitor screen and see how many savestreams there are running. Then look above and see how many tape drives.
e.g. 8 streams and 2 devices is good. 4 and 2 is not.

 

[angelshark]

During a regular backup there are 8 savestreams that run concurrently, being 4 savestreams on each tape drive.

Thanks for the feedback.