I have seen the minra option on the volume have a major affect on backup speed. Have you got it set to minra=on on any of your volumes?
Cheers Chris
----- Original Message ----- From: owner-toasters@mathworks.com owner-toasters@mathworks.com To: Toasters toasters@mathworks.com Sent: Fri May 09 16:02:14 2008 Subject: Max of 20MB/sec through FC attached LTO tape drive? Overland neo 2000
Asking here because we don't have current Overland support for the fibre channel card and I would guess it is more of a problem with the card rather than netapp (we only used the FCO with a netapp), but maybe someone has encountered this...
Around 2004 we bought a Overland Neo 2000 tape library with the FCO VIA scsi to FC converter board, and we got at most 20 or 25MB/sec through it (per tape drive) depending if we were writing or reading. This is both with NDMP dumps from the filer disks to tape, and also across the network into the filer to tape with NDMP. The backup software is Bakbone Netvault. Last year we tried attaching this library to a Unix host directly with SCSI and our speed almost doubled. I was floored, and shocked that we spent so many years missing out on performance, although 20-25 was the best I've seen anyone report for LTO2 so I never expected more.
Recently we bought another Neo 2000 with LTO4 drives, and I decided to move the FCO card over to it and try again, hoping maybe there was a misconfiguration, but I could not find any and it still acts as if there is a mystery cap on the speed of 20MB/sec (it averages 18-19 after it gets going). I've been all through the configuration of the FCO card and it is set to 160M/sec per scsi bus, tried with and without domain validation, and I even got the FC channel to operate at 2Gbit but no improvement. If I cannot figure this out then I will just attach it to the Unix host with the other neo 2000, but its always nice to have more options. I would not bother operating a LTO4 drive at such a slow speed in production because shoe-shining would probably wear it out and the compression would be sub optimal or non-existent. --------------------------------------------------------
Christopher Holloway Lead Consultant Professional Services
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Nope, I may have experimented with it on a volume not in production once, but I never tested backups in combination with it. The only options I have enabled anywhere on volumes are nosnap, nosnapdir, and root.
Holloway, Chris wrote:
I have seen the minra option on the volume have a major affect on backup speed. Have you got it set to minra=on on any of your volumes?
Cheers Chris
----- Original Message ----- From: owner-toasters@mathworks.com owner-toasters@mathworks.com To: Toasters toasters@mathworks.com Sent: Fri May 09 16:02:14 2008 Subject: Max of 20MB/sec through FC attached LTO tape drive? Overland neo 2000
Asking here because we don't have current Overland support for the fibre channel card and I would guess it is more of a problem with the card rather than netapp (we only used the FCO with a netapp), but maybe someone has encountered this...
Around 2004 we bought a Overland Neo 2000 tape library with the FCO VIA scsi to FC converter board, and we got at most 20 or 25MB/sec through it (per tape drive) depending if we were writing or reading. This is both with NDMP dumps from the filer disks to tape, and also across the network into the filer to tape with NDMP. The backup software is Bakbone Netvault. Last year we tried attaching this library to a Unix host directly with SCSI and our speed almost doubled. I was floored, and shocked that we spent so many years missing out on performance, although 20-25 was the best I've seen anyone report for LTO2 so I never expected more.
Recently we bought another Neo 2000 with LTO4 drives, and I decided to move the FCO card over to it and try again, hoping maybe there was a misconfiguration, but I could not find any and it still acts as if there is a mystery cap on the speed of 20MB/sec (it averages 18-19 after it gets going). I've been all through the configuration of the FCO card and it is set to 160M/sec per scsi bus, tried with and without domain validation, and I even got the FC channel to operate at 2Gbit but no improvement. If I cannot figure this out then I will just attach it to the Unix host with the other neo 2000, but its always nice to have more options. I would not bother operating a LTO4 drive at such a slow speed in production because shoe-shining would probably wear it out and the compression would be sub optimal or non-existent.
Christopher Holloway Lead Consultant Professional Services
*Main: +44 (0)1423 519000* *Direct: +44 (0)1423 519099* *Mobile: +44 (0)7867 783584* *Fax: +44 (0)1423 504415*
**
*DNS Arrow launches new enhanced customer portal - Inform an e-commerce partner tool to help customers save time and money in procurement. ** *For more information on Inform, please contact your account manager on *0800 983 2525* or register for an account at *www.dnsarrow.co.uk/inform* http://www.dnsarrow.co.uk/inform
*DNS Arrow*
Nidderdale House Beckwith Knowle Harrogate HG3 1SA *www.DNSarrow.co.uk* http://www.dnsarrow.co.uk/
Email Confidentiality Notice:* *This message is private and confidential. If you have received this message in error, please notify us and remove it from your system.
"DNS Arrow" means Digital Network Services (UK) Limited, a company registered in England. Company Registration Number 3952678.
Registered Office: Nidderdale House, Otley Road, Beckwith Knowle, Harrogate HG3 1SA, UK.
**
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Adam McDougall -
Holloway, Chris