Date: Thu, 28 Jul 2005 01:07:22 +0100 From: ".VWV." <victorvittorivonwiktow@interfree.it> To: <freebsd-questions@freebsd.org> Subject: Re: certance DAT Message-ID: <000901c59308$5710fe00$98edfea9@workstation> References: <007b01c59251$925c5ca0$98edfea9@workstation> <42E6FCC5.8070309@mac.com> <6.1.0.6.2.20050726211444.18e82a00@cobalt.antimatter.net>
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[Technicians' or hackers' suggestions seem like music to me. Thanks. I am compelled on this shit system, owing to the need of managing some commercial stuff. I hate it. Please forgive me for using it]. I have compared some features among different current tape drive standards. It seems DLT and LTO Ultrium 2 cartridges are more expensive then DAT 72 and VXA 2 ones. I have not found yet a criterion useful to choose the most reliable standard. Any suggestion could be useful. I'll need either to dump or to tar. Please CC me. Thanks once more. .VWV. ---- Original Message ---- From: "Glenn Dawson" <glenn@antimatter.net> To: "Chuck Swiger" <cswiger@mac.com>; ".VWV." <victorvittorivonwiktow@interfree.it> Cc: <freebsd-questions@freebsd.org> Sent: Wednesday, 27 July, 2005 05:19 Subject: Re: certance DAT > At 08:17 PM 7/26/2005, Chuck Swiger wrote: > ...so it's not exactly super-zippy, either. Hmm, is it just me, or > are the following numbers significantly low for a RAID-1 of two 10K > RPM U320 SCSI disks...? > >> /dev/amrd1 >> 512 # sectorsize >> 73274490880 # mediasize in bytes (68G) >> 143114240 # mediasize in sectors >> 8908 # Cylinders according to firmware. >> 255 # Heads according to firmware. >> 63 # Sectors according to firmware. >> >> Seek times: >> Full stroke: 250 iter in 1.824059 sec = 7.296 msec >> Half stroke: 250 iter in 1.805398 sec = 7.222 msec >> Quarter stroke: 500 iter in 4.254147 sec = 8.508 msec >> Short forward: 400 iter in 2.821081 sec = 7.053 msec >> Short backward: 400 iter in 2.860203 sec = 7.151 msec >> Seq outer: 2048 iter in 8.821875 sec = 4.308 msec >> Seq inner: 2048 iter in 9.006505 sec = 4.398 msec >> Transfer rates: >> outside: 102400 kbytes in 9.242111 sec = 11080 >> kbytes/sec middle: 102400 kbytes in 9.230325 sec = >> 11094 kbytes/sec inside: 102400 kbytes in 10.779231 >> sec = 9500 kbytes/sec >> >> [ This is running RELENG_5_4... ] > > I would have expected the transfer rates to be about twice what > they're listed as here. Though I don't know how you measured them. > > If you want to see something interesting, create a ufs1 file system > on the same raid 1 using FreeBSD 4.x. Then mount it in 5.x and do > your test for transfer rates. Compare that to either ufs1 or ufs2 on > the same raid 1 as created by 5.4. > > The results are very interesting. > > -Glenn > > >> -- >> -Chuck
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