Solved

LTO5 Tape Drive Assistance

Posted on 2011-09-21
20
1,597 Views
Last Modified: 2012-05-13
Hi There!

We have a brand new ML350G6 with a P212 SAS Controller driving a LTO 3280 SAS Full height tape drive. For some reason despite the specs reporting this tape drive can backup 1TB an hour, we seem to be only be able to get 120GB an hour which is quite a lot less (and comparable to LTO2 performance). This is using Backup Exec 2010 R3 with Symantec Drivers and fully updated. I am not sure if that is 1TB Compressed but I would presume that we should be able to get at least twice or three times the rate we currently do.

We are running 2008 R2 all updates and drivers are up to date.

I believe this is a 3Gb/s controller, I have seen that it supports 6Gbps controllers, but I can't seem to find one certified to work and does it require a different cable?

Is anyone else with this tape drive able to let me know what speeds they are getting please?


0
Comment
Question by:networkn
  • 9
  • 3
  • 3
  • +3
20 Comments
 
LVL 9

Expert Comment

by:Lester_Clayton
ID: 36578816
1 TB an hour is just a theoretical maximum, and it's always based on assuming you're getting 2:1 hardware compression.  Nobody gets these kinds of compression ratios on real data these days.  The only way you're going to be able to see better speeds than what you're seeing right now is if you do a Disk to Disk to Tape backup.  Backup Exec supports this out of the box.

This means you get a huge amount of storage which is directly attached to your Backup Server, and you back up all of your sources - simultaneously if you like - to the storage.  After that, you back it up to tape.  Backup Exec will stream all the data from the source servers, store it in large cabinet files on the Backup Storage, and then stream it all to tape.  Streaming huge files to tape will give you the fastest throughput by far, and you will be hitting huge speeds with this.  See attached image for a diagram of how this would work.

One small problem though - the bottleneck is now the network!

Gigabit Ethernet has a theoretical maximum of 125 MB/sec.  Nobody ever gets this.  Let's say 100 MB/sec for good measure, this is a very attainable average speed.

100 Megabytes a Sec = 6 Gigabytes a minute = 360 Gigabytes an hour.

If you have 2 Terabytes to back up, you could be looking at a looong backup window.

But there's light at the end of the tunnel!  People these days don't backup at night anymore - they back up CONTINUOUSLY!  I use DPM, which does synchronizations every 15 minutes to 1 hour, depending on my data type, to Disk.  This means it copies changed stuff to the disk, and everything else is skipped.  When it goes off to do the tape backups, it reads the backups it's made to disk and streams that directly to tape - SUPERFAST!

The gigabit link is no longer a bottleneck, because your backup is updating itself all the time.

Hope this has been food for thought.
BackupDiskToDiskToTape.png
0
 
LVL 4

Expert Comment

by:alexeykomarov
ID: 36578817
Hi
The bottle-neck a disk-system of the server which  is backuped.
0
 

Author Comment

by:networkn
ID: 36578887
My issue is that whilst I never in a million years expect to get 1TB an hour, I believe it's not unreasonable to expect 1/5 of that which is 200GB an hour. I have LTO3 and LTO4 drives doing 160GB an hour and they are half height on lesser spec servers. I can't believe the SAS Disks are the bottleneck? This is a local server backup, no network.

Where do you do backup to disk to tape in backup exec?
0
 
LVL 4

Expert Comment

by:alexeykomarov
ID: 36578914
How many Disk in the server? Raid level? what disk type?
0
 

Author Comment

by:networkn
ID: 36578936
2 x SAS 2.5" in a mirror, P410 SAS controller
0
 
LVL 4

Expert Comment

by:alexeykomarov
ID: 36579058

2.5 SAS disk will theoretically support 60 MB/s sustained throughput
0
 
LVL 12

Expert Comment

by:TapeDude
ID: 36579636
The speed of transfer of your SAS discs will mainly depend on their platters' rotational speed - a 15k rpm drive is obviously going to suck data off its discs a great deal faster than one plodding along at 5.4k.

Furthermore, compressibility of the data makes very little difference to the speed of the tape drive because the actual speed of the tape past the heads isn't usually the bottleneck, unless the drive has dirty heads or you're using bad media, and the drive is shoe-shining.

I would expect you to get at least 200GB per hour on a local backup on your current system. Is the data on the RAID badly fragmented? That would slow things down. Are you using the software compression and/or encryption option in Backup Exec? That would slow things down even more.

Have you run any tests on your system's hard disc throughput? Is the Windows 2008 fairly clean (ie, not too many programs installed, and you've turned off unneeded services)?

Do you have an anti-virus checker installed? Have you tried running the backup with it switched off?
0
 
LVL 55

Assisted Solution

by:andyalder
andyalder earned 250 total points
ID: 36579699
>I have LTO3 and LTO4 drives doing 160GB an hour

LTO4 should do 432GB/hour (2:1 compression) 216GB/hour native, since you are only getting 160GB/hour you can't feed the LTO4 fast enough so you will be constantly repositioning (shoe-shining) - you're actually just on the edge of not driving it fast enough since it can slow down to 40BM/s.

With an LTO5 you need to feed it faster than that so you'll be shoe-shining even more and so the LTO5 runs slower than the LTO4. That's a standard problem, the faster tape drive goes slower than the slower one if your disks aren't fast enough to feed it.
0
 

Author Comment

by:networkn
ID: 36579704
Hi There!

Thanks for the questions tapedude.

1) These are 10K Drives.
2) Brand new tape drive, brand new media, brand new install of windows, brand new everything. I would imagine fragmentation is minimal. Not much running, just the standard HP Stuff. I need to update the PSP to the latest version. Settings in BE are as default, so I'll check, but I think it uses hardware or nothing by default, I have actually had reasonable luck with software compression vastly improving speeds on LTO4 drives, but that isn't set.

No AV at this stage.
0
 
LVL 55

Expert Comment

by:andyalder
ID: 36579845
Enabling software compression generally disables hardware compression so in effect you've slowed the tape drive down a bit, that would explain why it's a bit faster. You could always do a system performace test with HP Library and Tape Tools, that's got disk subsystem tests as well as tape drive tests.
0
Give your grad a cloud of their own!

With up to 8TB of storage, give your favorite graduate their own personal cloud to centralize all their photos, videos and music in one safe place. They can save, sync and share all their stuff, and automatic photo backup helps free up space on their smartphone and tablet.

 

Author Comment

by:networkn
ID: 36579863
Yah I'll try some additional tests.

I would still like to hear from someone who actually has an LTO5 and BE2010 and see what data transfer rates they are getting.
0
 
LVL 16

Accepted Solution

by:
Gerald Connolly earned 250 total points
ID: 36582917
I agree with @andyalder, your scenario is a classic one. Upgrading from one version of LTO to a later one and the backups go slower, you can find this question asked time after time in this forum and it always comes down to shoe-shining.

LTO tape drives from all vendors have a minimum speed they can stream from, 40MB/sec for LTO-4 AND 47MB/sec for LTO-5, and if you are expecting compression of 2:1 you need to be feeding the drive at a minimum of 94MB/sec (for LTO-5).
0
 

Author Comment

by:networkn
ID: 36585008
c: to tape : 1.9GB/m
c: to tape (Compression via software only) : 1054MB/M
c: to d: via B2D (compression set to software) (Partition on same mirrored hdd's) : 3.3GB/m
d: to tape : 8GB/m
d: to e: (Separate HDD on same raid controller) 5GB/m
0
 
LVL 16

Expert Comment

by:Gerald Connolly
ID: 36585107
Minimum streaming speed for a LTO-5, 47MB/sec = 2820MB/min = 2.82GB/min
0
 
LVL 12

Expert Comment

by:TapeDude
ID: 36587097
If the drive IS shoe shining, then switching off the drive's hardware compression might increase the speed the tape is moving at to the point that it will stream.
0
 
LVL 55

Expert Comment

by:andyalder
ID: 36587325
Shoving some local cache on the P212 controller can also help by buffering the data so instantaneous compression gets averaged out a bit, but the only real fix is more disks in the staging pool.
0
 

Author Comment

by:networkn
ID: 36972570
We eventually got to around 4.7GB a minute, though I am unfortunately unsure exactly how, it seems like it just started working. At this stage I am not certain how to close this question
0
 

Author Comment

by:networkn
ID: 36972571
Connolly: I am not sure what you mean by minimum streaming speed?
0
 

Author Comment

by:networkn
ID: 36972572
connelly: ah never mind I see it explained in an earlier post by you.
0
 

Author Closing Comment

by:networkn
ID: 37963125
Whilst I am not sure what the issue was, it's just a case of making the most of the answers I got.
0

Featured Post

Highfive Gives IT Their Time Back

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

Join & Write a Comment

AWS Glacier is Amazons cheapest storage option and is their answer to a ‘Cold’ storage service.  Customers primarily use this service for archival purposes and storage of infrastructure backups.  Its unlimited storage potential and low storage cost …
Restoring deleted objects in Active Directory has been a standard feature in Active Directory for many years, yet some admins may not know what is available.
This tutorial will walk an individual through the steps necessary to join and promote the first Windows Server 2012 domain controller into an Active Directory environment running on Windows Server 2008. Determine the location of the FSMO roles by lo…
This tutorial will walk an individual through setting the global and backup job media overwrite and protection periods in Backup Exec 2012. Log onto the Backup Exec Central Administration Server. Examine the services. If all or most of them are stop…

705 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

19 Experts available now in Live!

Get 1:1 Help Now