Re: Ultrium tapetype
On Sun, 19 Mar 2006 at 12:30pm, stan wrote On Wed, Mar 15, 2006 at 09:31:17AM -0500, Joshua Baker-LePain wrote: FYI, I found that I got faster speeds with LTO3 by using larger than the default blocksize of 32KB. My nightly amanda backups get ~70MB/s using 2MB blocks. I went back and tries this, and at least with my current hardware, it's quite a bit slower: As an aside, I did my testing with tar, not amtapetype. speed 6952 kps Yeah, that's not so good. Hopefully when my new PCI-X SCSI card shows up, this will get a lot better. What's it hooked up to now? -- Joshua Baker-LePain Department of Biomedical Engineering Duke University
Re: Ultrium tapetype
On Wed, Mar 15, 2006 at 09:31:17AM -0500, Joshua Baker-LePain wrote:
> On Wed, 15 Mar 2006 at 6:50am, stan wrote
>
> >Here is the tapetype I got for my HP SorageWorks 960
> >Ultrium 3 unit.
> >
> >Hopefully it will help others.
> >
> >define tapetype unknown-tapetype {
> > comment "just produced by tapetype prog (hardware compression off)"
> > length 386048 mbytes
> > filemark 0 kbytes
> > speed 49993 kps
> >}
>
> FYI, I found that I got faster speeds with LTO3 by using larger than the
> default blocksize of 32KB. My nightly amanda backups get ~70MB/s using
> 2MB blocks.
I went back and tries this, and at least with my current hardware, it's
quite a bit slower:
[EMAIL PROTECTED]:/usr/local/src/pd/amanda/amanda-2.5.0b2/tape-src#
./amtapetype -o -e 400G -b 2M -f /dev/st0
Writing 256 Mbyte compresseable data: 39 sec
Writing 256 Mbyte uncompresseable data: 41 sec
Estimated time to write 2 * 409600 Mbyte: 131200 sec = 36 h 26 min
wrote 192512 2048Kb blocks in 94 files in 56755 seconds (short write)
wrote 193536 2048Kb blocks in 189 files in 56957 seconds (short write)
define tapetype unknown-tapetype {
comment "just produced by tapetype prog (hardware compression off)"
length 386048 mbytes
filemark 0 kbytes
speed 6952 kps
}
Hopefully when my new PCI-X SCSI card shows up, this will get a lot better.
--
U.S. Encouraged by Vietnam Vote - Officials Cite 83% Turnout Despite Vietcong
Terror
- New York Times 9/3/1967
Re: Ultrium tapetype
On Wed, 15 Mar 2006 at 11:31am, Jon LaBadie wrote I'm on really shakey ground here, but doesn't the tape have to be relabeled to get the tape header set to the new block size? IIRC, amanda rewrites the tape header at the start of every amdump. -- Joshua Baker-LePain Department of Biomedical Engineering Duke University
Re: Ultrium tapetype
On Wed, Mar 15, 2006 at 11:04:53AM -0500, Joshua Baker-LePain wrote: > On Wed, 15 Mar 2006 at 4:14pm, Alexander Jolk wrote > > >Joshua Baker-LePain wrote: > >>For amdump and friends, blocksize is set in the tapetype. For > >>amtapetype, you can set it on the command line. 'man amanda.conf' and > >>'man amtapetype' are your friends. > > > >When changing the blocksize, will amanda happily read (restore) older > >tapes written with a different blocksize, or will I have to recover them > >manually? Will she correctly overwrite recycled tapes with the new > >blocksize? > > Amanda will happily restore older tapes -- amrestore can determine the > blocksize itself and/or you can specify it on the command line. And > I'm fairly certain it'll overwrite recycyled tapes, but that's easily > tested. I'm on really shakey ground here, but doesn't the tape have to be relabeled to get the tape header set to the new block size? Or maybe it can be read at the 32K size, and when rewritten by taper becomes the new size automagically. -- Jon H. LaBadie [EMAIL PROTECTED] JG Computing 4455 Province Line Road(609) 252-0159 Princeton, NJ 08540-4322 (609) 683-7220 (fax)
Re: Ultrium tapetype
On Wed, 15 Mar 2006 at 4:14pm, Alexander Jolk wrote Joshua Baker-LePain wrote: For amdump and friends, blocksize is set in the tapetype. For amtapetype, you can set it on the command line. 'man amanda.conf' and 'man amtapetype' are your friends. When changing the blocksize, will amanda happily read (restore) older tapes written with a different blocksize, or will I have to recover them manually? Will she correctly overwrite recycled tapes with the new blocksize? Amanda will happily restore older tapes -- amrestore can determine the blocksize itself and/or you can specify it on the command line. And I'm fairly certain it'll overwrite recycyled tapes, but that's easily tested. -- Joshua Baker-LePain Department of Biomedical Engineering Duke University
Re: Ultrium tapetype
Alexander Jolk wrote: > When changing the blocksize, will amanda happily read (restore) older > tapes written with a different blocksize, or will I have to recover > them manually? Will she correctly overwrite recycled tapes with the > new blocksize? I believe the blocksize just affects how much data is read/written at once to/from the tape, it doesn't affect the actual data at all. Someone please correct me if I'm wrong? :) Graeme
Re: Ultrium tapetype
Joshua Baker-LePain wrote: For amdump and friends, blocksize is set in the tapetype. For amtapetype, you can set it on the command line. 'man amanda.conf' and 'man amtapetype' are your friends. When changing the blocksize, will amanda happily read (restore) older tapes written with a different blocksize, or will I have to recover them manually? Will she correctly overwrite recycled tapes with the new blocksize? Alex -- Alexander Jolk / BUF Compagnie tel +33-1 42 68 18 28 / fax +33-1 42 68 18 29
Re: Ultrium tapetype
Joshua Baker-LePain wrote: > Well, you have to be careful with LTO3. You want to feed the tape at > at least 1/2 native speed (native speed is rated to be 80MB/s). > Slower than that, and the drive will have to start and stop the tape > frequently (aka shoe-shining), which is bad for both tapes and the > drive (and capacity, for that matter). This generally means actually > putting some thought/$$ into the backup server's disk system. Yep, I'm not having any problems there, I've got some SATA discs in RAID 0 for the dump drives, so they can blast out at 60+MB/sec. > For amdump and friends, blocksize is set in the tapetype. For > amtapetype, you can set it on the command line. 'man amanda.conf' and > 'man amtapetype' are your friends. Cool, I'll look into that, I'm actually upgrading out backup server today, so now's a good time to play with that. Thanks! Graeme -- Graeme Humphries ([EMAIL PROTECTED]) (306) 955-7075 ext. 485 My views are not the views of my employers.
Re: Ultrium tapetype
On Wed, 15 Mar 2006 at 8:40am, Graeme Humphries wrote Joshua Baker-LePain wrote: FYI, I found that I got faster speeds with LTO3 by using larger than the default blocksize of 32KB. My nightly amanda backups get ~70MB/s using 2MB blocks. Hrm... I'm not being tapespeed limited (yet), but where do you configure the blocksize in Amanda? Well, you have to be careful with LTO3. You want to feed the tape at at least 1/2 native speed (native speed is rated to be 80MB/s). Slower than that, and the drive will have to start and stop the tape frequently (aka shoe-shining), which is bad for both tapes and the drive (and capacity, for that matter). This generally means actually putting some thought/$$ into the backup server's disk system. For amdump and friends, blocksize is set in the tapetype. For amtapetype, you can set it on the command line. 'man amanda.conf' and 'man amtapetype' are your friends. -- Joshua Baker-LePain Department of Biomedical Engineering Duke University
Re: Ultrium tapetype
Joshua Baker-LePain wrote: > FYI, I found that I got faster speeds with LTO3 by using larger than > the default blocksize of 32KB. My nightly amanda backups get ~70MB/s > using 2MB blocks. Hrm... I'm not being tapespeed limited (yet), but where do you configure the blocksize in Amanda? Graeme -- Graeme Humphries ([EMAIL PROTECTED]) (306) 955-7075 ext. 485 My views are not the views of my employers.
Re: Ultrium tapetype
On Wed, 15 Mar 2006 at 6:50am, stan wrote
Here is the tapetype I got for my HP SorageWorks 960
Ultrium 3 unit.
Hopefully it will help others.
define tapetype unknown-tapetype {
comment "just produced by tapetype prog (hardware compression off)"
length 386048 mbytes
filemark 0 kbytes
speed 49993 kps
}
FYI, I found that I got faster speeds with LTO3 by using larger than the
default blocksize of 32KB. My nightly amanda backups get ~70MB/s using
2MB blocks.
--
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University
