Slow back-up speeds 10.1d & Setting question

[Charles_Eberhar]

I have looked over the few tech support topics on slow backup speeds but I just can't figure out what is going on.

Im running 10d (10.1). My tape drive is a LTO-3 (Ibm td3). Im trying to back up my file store (home directories and the such) on another server using the remote agent. The server is in the same rack connected by a gigabit lan & switches. The backup speeds are just aweful @ about 250mb/min. I do not understand why these files take so long to back up. I can copy them over the network at lightning speeds. The tape drive can write at up to 60 mb a sec so I don't know what the problem could be.

One interesting note is that I can backup my exchange store, at a more acceptable speed of 2+gb a min (130+gb verified in under 2 hours... way more acceptable). However anything else is just slow as all getup. What is it with veritas and large amount of files?

I have defragged the files, all the bios settings appear to be ok, drivers are up to date. So im at a loss.

I do have a question about the preferred configuration for the tape drive though. Can anyone tell me what the preferred configuration settings should be for my IBM ULTRIUM TD3 tape drive should be? Its in the new Powervault 124-T we installed.

Anyone have any ideas about my speed issue and the settings?

[Ken_Putnam]

From the devices tab, right click the tape drive\properties

What are the settings for block size, buffer size, number or buffers, both single block settings and both pasthru settings?

[Charles_Eberhar]

Thanks for the reply Ken,

Here are the settings you requested. I think they are all default. They are as follows:

Enable Compression: Checked

Block Size: 64k
Buffer Size: 64k
Buffer Count: 10
Highwater: 0

Read single block mode: Unchecked
Write single block mode: Checked
Read SCSI pass-through mode: Unchecked
Write SCSI pass-through mode: Checked

[Ken_Putnam]

Unless tape drive is on a SAN, both pass-through settings should be off

Both single block settings should also be deselected, as this totally bypasses buffering. (though you said that the Exchange backups were much faster)

[Charles_Eberhar]

Ok I'll change those settings and give it a try tonight. Would those check boxes make that big of a difference?

[Ken_Putnam]

Single Block bypasses buffering so that BackupExec reads a data block, writes that block, then read the next etc. This can really reduce throughput

The only problem is that you say that your Exchange backups are very fast, and these settings are global, not by job. It's definitely worth a try tho

[Charles_Eberhar]

No change. The speed is still sitting around 250mb / min. :( Very frustrating. I'm not sure what to look at here. All the servers are connected by gigabit to a gig switch. I would think the speeds would be faster than this.

I tried maxing the cache size and number of them, no help there. Seems like the drive loves to write slow on these backups. :(

[Amruta_Bhide]

Hello Charls,

Since your Exchange Backups seem to be working fine, it is hard to check why the File Backups take longer.
You mentioned there are a HUGE number of files that you are backing up. The only reason in this case could be that, Backupexec backsup METADATA of the files along with the File in itself. So larger the number of files more the amount of time it will take.


You can still try the following Steps to check if the Device onfiguration atleast is fine:

- Install the latest Drivers for the 10d Version:
Symantec Backup Exec (tm) 10d (10.1.5629) - Device Driver Installer (20061015) - Includes Tape Driver Release (23) and Robotic Library Release (67) (Intel Only) http://seer.support.veritas.com/docs/285593.htm

- Check if the Firmware is on the latest Version as well

- Check the NIC Card Settings. The Duplex Mode of the NICs should not be on AUTO. It should be set to either Full Duplex or Half Duplex on all sides and machines in the Environment.

- Stop and disable the RSM Service.

- The SCSI ID of the device should be kept between 2-5. If this is a Library, the SCSI ID of the chnager should be lower than that of the drive.

________________________________________________________________

Apart from that, also check if how the Backup to disk Backup works. Does it give approximately the same throughput?


We will await an Update from you......


Thanks
RegardsMessage was edited by:
Amruta Bhide

[Charles_Eberhar]

Ugh..... ~_~

I did this step:

- Install the latest Drivers for the 10d Version:
Symantec Backup Exec (tm) 10d (10.1.5629) - Device Driver Installer (20061015) - Includes Tape Driver Release (23) and Robotic Library Release (67) (Intel Only) http://seer.support.veritas.com/docs/285593.htm

Now my back-ups are running at 2mb /min. :(
How frustrating. Working on this now lol.

[Ken_Putnam]

Double check you settings again

Some of the Symantec defaults are completely screwy

[roy_duque_de_es]

I am having the same problem. Except its my exchange mailboxes that are taking 6hrs to backup..(not verify, just backup). 51gb.
I dont know what to do, i have a powervaul 124-t also, and am using dell tapes. The server that has the backup software is my domain controller, and the exchange server are all on the same gb switch.
my rate for the backup is 128mb/min for the exchange mailboxes. Anyone help would be appreciated. Below is a screenshot of my tape drive properties.


i will also get this message every once in a while at the autoloader screen.

Tape Alerts: Flags:0000000002000000

TA-DiagnosticsRqrd

[Ken_Putnam]

Exchange backups are by their nature slow. The workaround/klidege that Veritas came up with is to have the Service Account logonto outlook, connect to each selected mailbox in turn, and then open and "read" each itme using standard MAPI (OutLook) calls

We've seen reports of speeds in the 15-20 MB/min range on decent hardware for mailbox backups

Take a look at mail.tekscan.com/nomailboxes.htm to see if you really want to do brick level backups in the first place. or just for few high profile users.

[roy_duque_de_es]

What exactly is deleted item retention, and how do I configure it in exchange?

[Hywel_Mallett]

Exchange mailbox backups are always slow... However, there's a lot of soft write errors there too. Are the tapes new?
To the original poster (Charles), if there are a large number of files, are they very small files? Backup throughput performance falls when you have large numbers of very small files.

[roy_duque_de_es]

They are relatively new.. i do weekly backups and rotate the tapes out every week. I got all new tapes when i bought the autoloader about 3-4 months ago.

[Charles_Eberhar]

This issue is closed for me for the moment. I upgraded to 11d so its off to the 11d forums. Thanks Ken.