Poor performance

[Eric_260]

Hello,

I know that there has been a lot of discussion on this. But I was unable to find the perfect solution to my problem.

I've looked and tried a lot of solution that i've found. Maybe I've found the wrong posts or... i don't know... But anyway! Here's my info :

Filesystem Statistics:

Directories ........ 21791
Regular files ...... 571147
Symbolic links ..... 425
SYSV FIFOs ......... 0
BSD sockets ........ 0
Block Devices ...... 0
Character Devices .. 0
Unknown Objects .... 0
----------------------------
Objects Total ...... 593363
Kbytes Total ...... 71519261

Run Time ........... 4:41:15
Backup Speed ....... 4238,18 (KB/s)

4 hours for 70 gigs ? Normally its suppose to be like 60/70 gigs for 1 hour using a single drive ?

We have a HP LTO-2 using SCSI-2

I've seen post about Disk agents, buffers and stuff like that... nothing worked.
I know that the more files that we have that might impact on the backup performance.

But anyway, if anyone might have a little advice that would be great!

Thanks!

[Steven E. Protter]

Have you been through this doc?

http://www6.itrc.hp.com/service/cki/search.do?category=c0&docType=Security&docType=Patch&docType=EngineerNotes&docType=BugReports&docType=Hardware&docType=ReferenceMaterials&docType=ThirdParty&searchString=UPERFKBAN00000726&search.y=8&search.x=28&mode=id&admit=1552802428+1091736050969+28353475&searchCrit=allwords

Attaching a script to help gather data for the doc.

SEP

[Patrick Wallek]

What are you using to write to tape? tar, cpio, fbackup, OmniBack/DataProtector?

[Eric_260]

Never got that doc before!

I'm going to read that right now!


To do the backups, i'm using Data Protector 5.1
on Windows.

The example of filesystem was from a drive for a Oracle instance.

But I get the same performance with other machines running on Unix or Windows.

[A. Clay Stephenson]

It's not clear what version of OB2/DP you are running. If you have already increased the data buffers and segment size, I doubt further tuning is going to help much.

I suspect that the fundamental bottleneck is that there not enough disk agents to keep the drive busy. Observe the tape drive while the backup is running. If the drive does not stream almost continuously then you are taking a huge (10-100X) performance hit compared with the throughput of a streaming device. OB2/DP really performs best with fast tape drives when multiple filesystems (in OB2 speak, objects) are feeding a common media agent. I suspect you could actually back 3 filesystems as fast as you back up the one. You might try the divide and conquer approach by using includes and excludes of different directories so that the same filesystem becomes different objects. You then make sure that the device concurrency is >= the number of objects.
The downside to the divide and conquer approach is that it is now rather eash to miss something when directories are added.
It also helps greatly if the disk agent and media agent are on the same host so that the network is not a bottleneck. Finally, you are backing up a fairly large number of files; each of these requires a database hit. A few large files will be much faster than many small files for the same total volume of data. The database under DP is improved considerably over that of OB2.
You might try reducing the logging level to "Log Directories" if you suspect that the database is a bottleneck.

[Eric_260]

Actually if I click on the link I get no results.

And the script seems to be for a Unix machine.
I'm installed on a Windows machine.

Don't know if that makes a good difference on speed.

I know that when I was running with my AIT device on Unix with Networker the performance was okay. When we switched the AIT device to Data Protector under windows, the performance was decreased.

Don't know if that's still the case now.

[Eric_260]

Here's the settings of my drives:

Hardware compression
Concurrency 4
Block Size (Default)
Segment size 2000
Disk Agent 8

I have a MSL6030 with 2 LTO2 Drives.

The backup machine use the network at 100%.
The CPU Performance is okay, most of the time the machine is in idle at 90% (during backups).

How can I determine that the issue is with the database of DP ?

[Ted Buis]

Are you saying you are backing up over the network? What type of network? You are not likely to keep the lto-2 drive streaming (without shoe-shining) even with GigE without pulling data from multiple sources at the same time. This is possible in DP. There must be something on this in the DP documentation.

[Eric_260]

Yes, doing backup over the network.

We are on 100Mbps.

When backing up 1 client, 1 big file, or even a disk i always get a network usage of about 30Mbps.

Since the drives are 30MBps, the network should be used at 100Mbps no ?

[Ted Buis]

The drives are 30 to 60 MBytes/second while 100BaseT is 100Mbits/second, or less than 10MBytes/second. Try multiple NICs and trunking or a GigE link. Also, the packet size of 1504bytes and TCP/IP overhead is also a big issue.