NEC DVD_RW - file read problems.
Hello All, I have the following problem: OS: FreeBSD 4.11-RELEASE. DVD RW: acd0: DVD-R _NEC DVD_RW ND-3500AG at ata1-master UDMA33 I use DVD R's primary for data backup. The backup data is archived and splitted on files ~500Mb size, which was written on DVD-R's. I have also store the MD5 sums of those files in small checksum file. The problem is: sometimes then i check content on DVD the checksum is differs. Where is no read errors on console, and several attempts to calculate checksum return different results. bash-2.05b# grep 1 /cdrom/md5.sums acc8b491f03bfa01e341808773a6f94f depot.147.tar.1 bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = d821bd902c4b0e9c12510f302c10ee71 # File seems cached in RAM bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = d821bd902c4b0e9c12510f302c10ee71 bash-2.05b# umount /cdrom # After unmounting and mounting again - different (correct) checksum. bash-2.05b# !mou mount /cdrom bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = acc8b491f03bfa01e341808773a6f94f # Now the checksum is OK. It seems for me that sometimes device correct soft read errors on media, and sometimes - does not. Does anybody have the same expirience (i.e. checksum differs without read errors) ? Best Regards, Alexander Derevyanko ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: NEC DVD_RW - file read problems.
On 10/25/05, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hello All, I have the following problem: OS: FreeBSD 4.11-RELEASE. DVD RW: acd0: DVD-R _NEC DVD_RW ND-3500AG at ata1-master UDMA33 I use DVD R's primary for data backup. The backup data is archived and splitted on files ~500Mb size, which was written on DVD-R's. I have also store the MD5 sums of those files in small checksum file. The problem is: sometimes then i check content on DVD the checksum is differs. Where is no read errors on console, and several attempts to calculate checksum return different results. bash-2.05b# grep 1 /cdrom/md5.sums acc8b491f03bfa01e341808773a6f94f depot.147.tar.1 bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = d821bd902c4b0e9c12510f302c10ee71 # File seems cached in RAM bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = d821bd902c4b0e9c12510f302c10ee71 bash-2.05b# umount /cdrom # After unmounting and mounting again - different (correct) checksum. bash-2.05b# !mou mount /cdrom bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = acc8b491f03bfa01e341808773a6f94f # Now the checksum is OK. It seems for me that sometimes device correct soft read errors on media, and sometimes - does not. Does anybody have the same expirience (i.e. checksum differs without read errors) ? Best Regards, Alexander Derevyanko ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] Проверь память. Поставь на ночь memtest или docmemory. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: NEC DVD_RW - file read problems.
I have already checked memory - all checks went OK. From: 25.10.2005 07:40:35 Andrew P. [EMAIL PROTECTED] To:Aleksandr Derevianko/RU/Transport/[EMAIL PROTECTED] cc:freebsd-questions@freebsd.org Security Level:? Internal Subject: Re: NEC DVD_RW - file read problems. On 10/25/05, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Hello All, I have the following problem: OS: FreeBSD 4.11-RELEASE. DVD RW: acd0: DVD-R _NEC DVD_RW ND-3500AG at ata1-master UDMA33 I use DVD R's primary for data backup. The backup data is archived and splitted on files ~500Mb size, which was written on DVD-R's. I have also store the MD5 sums of those files in small checksum file. The problem is: sometimes then i check content on DVD the checksum is differs. Where is no read errors on console, and several attempts to calculate checksum return different results. bash-2.05b# grep 1 /cdrom/md5.sums acc8b491f03bfa01e341808773a6f94f depot.147.tar.1 bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = d821bd902c4b0e9c12510f302c10ee71 # File seems cached in RAM bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = d821bd902c4b0e9c12510f302c10ee71 bash-2.05b# umount /cdrom # After unmounting and mounting again - different (correct) checksum. bash-2.05b# !mou mount /cdrom bash-2.05b# md5 /cdrom/depot.147.tar.1 MD5 (/cdrom/depot.147.tar.1) = acc8b491f03bfa01e341808773a6f94f # Now the checksum is OK. It seems for me that sometimes device correct soft read errors on media, and sometimes - does not. Does anybody have the same expirience (i.e. checksum differs without read errors) ? Best Regards, Alexander Derevyanko ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] Проверь память. Поставь на ночь memtest или docmemory. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
