Jump to content

Slow transfer speeds (Backup) but fast (Duplicate)


Recommended Posts

Hi guys,

 

When I run Retrospect (Workstation) on the G5 server (duplicate raid array to internal drive) this goes fine about 2500MB/min.

When I run Retrospect (Express or Workstation) on the G4 workstation (duplicate mounted server volume to ext firewire) this goes okay about 1000MB/min.

Now for the problems, when I run Retrospect (Express or Workstation) on the G4 workstation (backup mounted server volume to ext firewire) this goes VERY slow about 50MB/min!!

 

here are my specs:

 

Backup Mac

G4/400 10.3.9

Maxtor one-touch III firewire drives 2x500gb

Retrospect Express ver 6.0.195 (default)

Retrospect Workgroup ver 6.1.138 (temporarily using this just to test)

 

Server

G5 Dual 1.8ghz

Retrospect Workgroup ver 6.1.138

SmallTree dual 1000MB NIC

 

This happens on 3 different ext drives, I've only had this problem since I swapped servers over from a Linux box (which backed up fine around 800MB/min).

 

The workstation has a full admin account with the server and performs fine when using the 'duplicate' method but not when using 'backup'. I could really do with using the 'backup' incremental method as this suits my needs greater having the ability to go back a day or week.

 

confused, awaiting guidance LOL

 

bt

Link to comment
Share on other sites

This could be normal, depending on your firewire interface, bridge chips, etc. How many devices on the chain? Firewire 400 or 800? What does Apple System Profiler say for this external drive? What type of external drive? Amount of buffering in the drive? Drive rotation speed? And, some G4 firewire is, shall we say, less than optimal.

 

Russ

Link to comment
Share on other sites

Quote:

Quote:

Now for the problems, when I run Retrospect (Express or Workstation) on the G4 workstation (backup mounted server volume to ext firewire) this goes VERY slow about 50MB/min!!

 


 

- What Type of Backup Set are you using? "File" or "Removable Disk"?

 


 

File, I've always used this method without any problems until now.

 

 

Quote:

This could be normal, depending on your firewire interface, bridge chips, etc. How many devices on the chain? Firewire 400 or 800? What does Apple System Profiler say for this external drive? What type of external drive? Amount of buffering in the drive? Drive rotation speed? And, some G4 firewire is, shall we say, less than optimal.

 

Russ

 


 

There is only 1 device connected ATM firewire 400, the drives used (with the same results) are:

Maxtor OneTouch II 300gb 8mb 7200rpm

Maxtor OneTouch III 500gb 16mb x2 7200rpm

 

Later today I will have another 3 OneTouch 750gb drives and a couple of 1TB NAS drives to try but I know they will perform the same.

 

The problem IS NOT the firewire drives as they work fine when using Duplicate mode but slow whenever using Backup. The drives work fine whenever I use the Backup mode on any other of my servers. It must be to do with the Server, I will test later today using one of the new drives on my MacPro 3ghz Quad to see if I can replicate the problem.

 

many thanks

 

bt

Link to comment
Share on other sites

Quote:

It must be to do with the Server

 


 

Agreed.

 

> Backup Mac

> G4/400

 

 

The The Power Macintosh G4/400 (PCI Graphics) is based on the Yikes! architecture; it was actually a G3 logic board with what was then the new G4 CPU wedged on top. These machines have onboard FireWire that is, as Russ pointed out, often a problem.

 

Since you have another machine to test with, that's a good first step. If you need to use this older G4, I'd suggest a PCI based FireWire host adapter be used in this machine instead of the onboard bus.

 

Dave

Link to comment
Share on other sites

Unfortunately my parcel (containing new hard drives) has been lost by citylink frown.gif So I have to wait for new delivery to install retrospect that comes with the new OneTouch drives.

 

I have about 5 or 6 G4s under desks etc which I can't bring myself to throw away just yet! I figured they were more than capable to use as backup machines etc. Funny thing is, it's been used for backing up for many years with no issues until I moved back to a Mac server.

 

I'm convinced the problem lies with ACLs on the server, it seems to handle duplicating no worries but creating a backup set causes the trouble. I will see what tomorrow brings....

 

PS. The G4 I'm using is the AGP variant with gigabit NIC

 

bt

Link to comment
Share on other sites

Sorry for not replying sooner guys, I'm up to my neck in work and haven't got much time to put into fixing this.

 

Tried using a Maxtor OneTouch III 750gb drive (firewire 800) on my Macpro quad and I still only get 400-500MB/min, yet I can copy a DVD image file (4GB) in just over a minute from the same server! By just dragging the file off the server I can get nearly 10x the performance! What am I doing wrong, is this normal behaviour?

 

As for the ACLs it's just a hunch that they're to blame as I can't figure out why Incremental backups have become so slow all of a sudden. I've been using retrospect since 1992 (since my first ever python 2/4gb DAT drive!) and these are the slowest backups I've ever ran. The server is one of the fastest I've used (disk I/O) with the raid array topping 300MB/s Read/write. I am also using link aggregation to give me a 2GB/s duplexed ethernet port(s) so I know the 'server/disks/NICs' are not slowing things down.

 

bt

Link to comment
Share on other sites

Quote:

I am also using link aggregation to give me a 2GB/s duplexed ethernet port(s) so I know the 'server/disks/NICs' are not slowing things down.

 


MacOS link aggregation with the hardware you list does not use both links for the same connection; the kernel picks a link down in its bowels. It does, however, spread connections across the links, so link ag can help with lots of simultaneous connections, but not for a single connection.

Link to comment
Share on other sites

Ok, point taken, it's a smalltree PXG2 Dual Port Card, and I thought it did give me one fat connection but maybe not, anyhow as you said it should still rule out any NIC bandwidth issues with it's load balancing.

 

Maybe I will try to connect via the onboard NIC and run some tests to see if I still get the issues.

 

bt

Link to comment
Share on other sites

Quote:

it's a smalltree PXG2 Dual Port Card

 


Ah, new information. I thought you were using the onboard NIC because no special NIC information was provided. My error. The smalltree NIC (because it has its own driver) can, I believe, depending on what network infrastructure is at the other end, bond the ports to give total throughput on a connection. Onboard NIC cannot, and many switches cannot.

 

Russ

Link to comment
Share on other sites

Quote:

Tried using a Maxtor OneTouch III 750gb drive (firewire 800) on my Macpro quad and I still only get 400-500MB/min

 


 

Your Original Post stated that you were getting 50MB/Min with the same Source, but with the Destination File Backup Set stored on a different physical FW drive. Moving from the old G4 to a new modern Mac with a different FW drive has shown a 10x improvement in speed. So your making some headway!

 

> I'm convinced the problem lies with ACLs on the server...

 

{snip}

 

> As for the ACLs it's just a hunch that they're to blame...

 

Well, certainty or hunch, have you disabled Retrospect's handling of ACLs in any of your tests?

 

 

 

Dave

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...