I have several different combinations of this going on here with mixed results. On certain hardwares my fastest backups are writing a single data stream but with most starting 2nd,m 3rd or even 4th simultaneous streams is what produces the best results. I've been through the ringer on this one, but suffice to say that every system will not be the same so you are better off testing both. Different storage vendors handle multiple streams in different ways, and multiple spindles vs/ drive write speeds all create a complete mess. IMO you are better off trying 1 method, then next backup trying the next. Judge for yourself with your specific conditions because no blanket "this way works best" statement could possibly cover all the unknowns. -Jonathan
________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Weber, Philip Sent: Thursday, December 21, 2006 10:27 AM To: Steve Fogarty; veritas-bu@mailman.eng.auburn.edu Subject: Re: [Veritas-bu] Backup of Large Windows Volume It's a SAN-based volume so I'm not too worried about this, we do it elsewhere. Will have to keep an eye on it but current performance stats indicate I should be able to get the data off the disks faster with multiple streams. -----Original Message----- From: Steve Fogarty [mailto:[EMAIL PROTECTED] Sent: 21 December 2006 15:16 To: Weber, Philip; veritas-bu@mailman.eng.auburn.edu Subject: RE: [Veritas-bu] Backup of Large Windows Volume I don't think you want to have seperate streams from the same physical disk. This is from the Admin Doc. "For best performance, use only one data stream to back up each physical device on the client. Multiple concurrent streams from a single physical device can adversely affect backup times because the heads must move back and forth between tracks containing files for the respective streams." Your selections would probably "thrash" the disk pretty hard. Steve ________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Weber, Philip Sent: Thursday, December 21, 2006 10:45 AM To: veritas-bu@mailman.eng.auburn.edu Subject: [Veritas-bu] Backup of Large Windows Volume NetBackup 5.1 MP5, Solaris 9 master/media servers. I have a Windows 2000 client with approx 900 Gb D: drive which I want to split into multiple streams, e.g. Stream 1 : D:\Shares\shareddata\All Departments\folder1 (100 Gb) Stream 2 : D:\Shares\shareddata\All Departments (the rest - 130 Gb) Stream 3 : D:\Shares\shareddata\folder1 (160 Gb) Stream 4 : D:\Shares\shareddata\folder2 (52 Gb) D:\Shares\shareddata\folder3 (52 Gb) Stream 5 : D:\Shares\shareddata (the rest - 270 Gb) Stream 6 : D:\Shares (the rest - 130 Gb) As far as I can see I'll have to create separate policies for all of these, in order to be able to use exclude lists to prevent duplication of backups. Is there some way that I have missed where I can add these all to one policy using NEW_STREAM, and not get duplication of data? thanks, Phil Phil Weber Business Technology (Egg) Storage Technical Services - Senior UNIX Technologist ________________________________ Egg is a trading name of the Egg group of companies which includes: Egg plc (reg no 2448340), Egg Financial Intermediation Ltd (reg no 3828289), and Egg Banking plc (reg no 2999842). Egg Banking plc and Egg Financial Intermediation Ltd are authorised and regulated by the Financial Services Authority (FSA) and are entered in the FSA register under numbers 205621 and 309551 respectively. These members of the Egg group are registered in England and Wales. Registered office: Laurence Pountney Hill, London EC4R 0HH. This e-mail is confidential and for use by the addressee only. If you are not the intended recipient of this e-mail and have received it in error, please return the message to the sender by replying to it and then delete it from your mailbox. Internet e-mails are not necessarily secure. The Egg group of companies do not accept responsibility for changes made to this message after it was sent. Whilst all reasonable care has been taken to avoid the transmission of viruses, it is the responsibility of the recipient to ensure that the onward transmission, opening or use of this message and any attachments will not adversely affect its systems or data. No responsibility is accepted by the Egg group of companies in this regard and the recipient should carry out such virus and other checks as it considers appropriate. This communication does not create or modify any contract.
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