Date: Fri, 17 May 2013 10:30:59 +1000 From: Greg 'groggy' Lehey <grog@FreeBSD.org> To: Zaphod Beeblebrox <zbeeble@gmail.com> Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: tape (sa0) on sparc64 ? Message-ID: <20130517003058.GW77641@eureka.lemis.com> In-Reply-To: <CACpH0McOx_Kza-Ou-=ko724cehF0Kp3uhN%2B6mFy2L0GdLQ1ESg@mail.gmail.com> References: <CACpH0Mcass3ONxhFw5mRrQ1K931gxaxBZgo45_%2BynLrrbm4DUw@mail.gmail.com> <0D672BB1-1928-4F7A-BF72-CA7EE15D0563@gid.co.uk> <CACpH0McOx_Kza-Ou-=ko724cehF0Kp3uhN%2B6mFy2L0GdLQ1ESg@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
--Tln/wzp9jsNjmSUr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thursday, 16 May 2013 at 19:56:14 -0400, Zaphod Beeblebrox wrote: > On Thu, May 16, 2013 at 5:08 PM, Bob Bishop <rb@gid.co.uk> wrote: >> On 16 May 2013, at 21:51, Zaphod Beeblebrox wrote: >> >>> I have to retrieve some very old backups. They were made on FreeBSD and >>> are on tape... specifically DDS4. [etc] >>> However, attached to either controller (after a reboot of the machine >> and a >>> powercycle of the drive), I get: >>> >>> [1:25:325]root@run:/home/foo> dd if=/dev/sa0 of=tape5 >>> dd: /dev/sa0: Input/output error >>> 0+0 records in >>> 0+0 records out >>> 0 bytes transferred in 0.002930 secs (0 bytes/sec) >>> >>> ... which is a return code of '1' and no messages on the console... >>> >>> I have, before you ask, tried "bs=10k" and 20k ... but I believe this >>> command should run by itself fetching the first 512 bytes of each block >> --- >>> narrowing down the block size logically comes after making the tape go. >> >> >> Try bs=64k > > Same result. Besides, as far as I understand, the proper operation > (if the blocksize is too small) is to read the first $n bytes and > then write them to the output.. The obvious question: can you write tapes and read them back? My experience with DDS tapes was of extreme unreliability. The age doesn't make things any easier. Greg -- Sent from my desktop computer. Finger grog@FreeBSD.org for PGP public key. See complete headers for address and phone numbers. This message is digitally signed. If your Microsoft MUA reports problems, please read http://tinyurl.com/broken-mua --Tln/wzp9jsNjmSUr Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iEYEARECAAYFAlGVekIACgkQIubykFB6QiNbnwCfes0z89YVMRVVQEnUe0NzH+w0 uAIAn3XRJaVEt2+55iM7vzRYWNTUmPa2 =IEct -----END PGP SIGNATURE----- --Tln/wzp9jsNjmSUr--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20130517003058.GW77641>