[Bacula-users] How much available space on the tape?
Hi, I've been using Bacula for 3 days now, and it works great. Thanks to all the devs. I have an LTO-2 (200/400 GB) tape drive, and I need to backup around 43 GB of data from Monday to Friday. I bought five tapes, and I intend to set up five pools: Mon, Tue, Wed, Thu, and Fri. Each tape will be used four times (four Monday, four Tuesdays, etc), then recycled. But I suspect that hardware compression would allow me to use each tape more than four times before recycling - how can I find about this? Is there any way to know how much available space a tape still has? I used BrightStor Enterprise Backup at my former job, and it had its share of annoyances, but one of its nice features was just that - telling me how much data I could still write to a particular tape. Regards, Georger ___ Abra sua conta no Yahoo! Mail: 1GB de espaço, alertas de e-mail no celular e anti-spam realmente eficaz. http://br.info.mail.yahoo.com/ --- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
Re: [Bacula-users] How much available space on the tape?
Sure, but a tape has a fixed number of blocks; I think it would be possible to know how many of them are used and how many are left? The compression rate isn't the most important factor - say you have a 200 GB tape divided in 200 blocks, each 1 GB in size (insane, yeah). If Bacula wrote up to the 100th block in the last backup, it doesn't really matter if I have 100 GB of uncompressed data or 500 GB of compressed data; what REALLY matters is that I can write AT LEAST more 100 GB to the tape, because I have 100 blocks left. Regards, Georger --- Ryan Novosielski [EMAIL PROTECTED] escreveu: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 You can't really tell how much free space there is, because you can't really tell how well the data you're going to write will compress. Ryan Novosielski - ___ Abra sua conta no Yahoo! Mail: 1GB de espaço, alertas de e-mail no celular e anti-spam realmente eficaz. http://br.info.mail.yahoo.com/ --- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
Re: [Bacula-users] How much available space on the tape?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 You can't really tell how much free space there is, because you can't really tell how well the data you're going to write will compress. _ _ _ _ ___ _ _ _ |Y#| | | |\/| | \ |\ | | |Ryan Novosielski - User Support Spec. III |$| |__| | | |__/ | \| _| |[EMAIL PROTECTED] - 973/972.0922 (2-0922) \__/ Univ. of Med. and Dent.|IST/AST - NJMS Medical Science Bldg - C630 Georger Araujo wrote: Hi, I've been using Bacula for 3 days now, and it works great. Thanks to all the devs. I have an LTO-2 (200/400 GB) tape drive, and I need to backup around 43 GB of data from Monday to Friday. I bought five tapes, and I intend to set up five pools: Mon, Tue, Wed, Thu, and Fri. Each tape will be used four times (four Monday, four Tuesdays, etc), then recycled. But I suspect that hardware compression would allow me to use each tape more than four times before recycling - how can I find about this? Is there any way to know how much available space a tape still has? I used BrightStor Enterprise Backup at my former job, and it had its share of annoyances, but one of its nice features was just that - telling me how much data I could still write to a particular tape. Regards, Georger ___ Abra sua conta no Yahoo! Mail: 1GB de espaço, alertas de e-mail no celular e anti-spam realmente eficaz. http://br.info.mail.yahoo.com/ --- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.2.2 (MingW32) iD8DBQFEbhUamb+gadEcsb4RAgMJAKC+gXH5Hbp4zbCLhR069kwtsnxovQCgn+Qa aT0IZpTuH9WqcrcrQygTNNQ= =gjJj -END PGP SIGNATURE- --- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid0709bid3057dat1642 ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
Re: [Bacula-users] How much available space on the tape?
Hello, On 5/19/2006 9:59 PM, Georger Araujo wrote: Sure, but a tape has a fixed number of blocks; Unfortunately, not. I think it would be possible to know how many of them are used and how many are left? The compression rate isn't the most important factor - say you have a 200 GB tape divided in 200 blocks, each 1 GB in size (insane, yeah). If Bacula wrote up to the 100th block in the last backup, it doesn't really matter if I have 100 GB of uncompressed data or 500 GB of compressed data; what REALLY matters is that I can write AT LEAST more 100 GB to the tape, because I have 100 blocks left. That's not how hardware compression for tapes work. You write blocks of, say, 1 GB to to tape, and depending on how good that data can be compressed the length of tape (usually, the length of the track(s)) used vary. You really can't know how much data fits on a tape before measuring it, and if hardware compression is on your results areonly valid for your test data. Softwarwe that claims to know exactly how much tape space is left usually lies, or, expressed differently, estimates. By the way: I wrote a small perl program to estimate available tape space, based on how much data is stored on tape volumes with comparable characteristics (i.e. Media Type). Arno Regards, Georger --- Ryan Novosielski [EMAIL PROTECTED] escreveu: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 You can't really tell how much free space there is, because you can't really tell how well the data you're going to write will compress. Ryan Novosielski - ___ Abra sua conta no Yahoo! Mail: 1GB de espaço, alertas de e-mail no celular e anti-spam realmente eficaz. http://br.info.mail.yahoo.com/ --- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users -- IT-Service Lehmann[EMAIL PROTECTED] Arno Lehmann http://www.its-lehmann.de --- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid0709bid3057dat1642 ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
Re: [Bacula-users] How much available space on the tape?
On Fri, May 19, 2006 at 10:35:02PM +0200, Arno Lehmann wrote: Softwarwe that claims to know exactly how much tape space is left usually lies, or, expressed differently, estimates. By the way: I wrote a small perl program to estimate available tape space, based on how much data is stored on tape volumes with comparable characteristics (i.e. Media Type). It would be reasonable for a tool to figure out how many feet of tape are remaining, then give a worst-case estimate of the remaining space. -Jason Martin -- Alone: In bad company. This message is PGP/MIME signed. pgp2ymqO3oZT7.pgp Description: PGP signature
