Below is a dialog with our F630 running 5.1.2P1 trying to read a tape written with 4.x. We were able to recover data from this tape using a filer running 4.3R4D2.
range> mt -f rst0l diag 1 Fri Dec 18 12:59:45 EST [tape_admin]: Tape driver diagnostic messages enabled. range> mt -f rst0l status Tape drive: Digital DLT7000 Status: ready, write protected Format: 81633 bpi 40 GB (w/comp) fileno = 0 blockno = 0 resid = 0 range> restore tvf rst0l Fri Dec 18 13:00:12 EST [isp_main]: Tape (6.4):cmdblk 0xfffffc0000be7088 op 0x8 block 54272 no error (20 0, 0) RESTORE: Tape Block size should be 10240, not 64512. Fri Dec 18 13:00:12 EST [isp_main]: Tape block was shorter than byte count. Requested = 4096, Read = -50176 Fri Dec 18 13:00:12 EST [isp_main]: Tape (6.4) no sense data. RESTORE: Could not initialize media. range> restore tvfb rst0l 64512 RESTORE: No buffers available.
We now have a VERY strong suspicion that tapes written with 4.x cannot be read with 5.1.2P1.
Graydon Dodson grdodson@lexmark.com Lexmark International Inc.
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From stephen%netapp.com@interlock.lexmark.com Thu Dec 17 20:24:43 1998 From: stephen%netapp.com@interlock.lexmark.com (Stephen Manley) Subject: Re: 5.x Restore cannot read 4.x dumps To: grdodson@sol.lpdev.prtdev.lexmark.com Date: Thu, 17 Dec 1998 17:23:54 -0800 (PST) Cc: toasters%mathworks.com@interlock.lexmark.com
Anyone having problems restoring their dump tapes? We pulled a couple of old archive tapes (6 mo. old level 0 dumps) to restore some files and were unable to read them. Kept getting buffer size or buffer allocation errors. Placed a call to Tech. Sup. waiting for a callback (and waiting, and waiting, and waiting...).
While waiting we tried some experiments. The tapes were written on an F330 running 4.x NFS & CIFS enabled (so we cannot use a sun to restore them). We discovered that we could read recent tapes written by either an F630 or F330 on a F630 running 5.1.2P1 with NFS & CIFS.
I strongly suspect that a filer running 5.1.2P1 cannot read tapes written with 4.x. This has a less than pleasant affect on our backup & archive strategy.
Can anyone confirm this?
What's the exact error message?
You should be able to restore 4.x tapes on 5.1 systems, and 5.1 tapes on 4.x systems (obviously ACLs disappear)
Stephen Manley FS Recovery Superfan
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I've come to expect this sort of thing, ever since my second job, back in the mid-'80s, when we had to back out an OS upgrade (that was a cold reinstall and reload from backups) of a Stellar GS-1000, because the new version's restore(8) refused to read the leavings from the old version's dump(8).
These days, I've come to really like cpio; while it has many varients, I've had good luck reading GNU cpio's "-Hnewc" format with some vendor cpio programs, and it succeeds in representing the contents of a filesystem sufficiently completely and accurately so I can reload a complete system using cpio, fwhack the boot blocks, and boot the result.
In high-volume high-performance mass backup settings I'd probably hack up something around Amanda, going compression either locally or remotely but in any case staging the whole tape full to a big horking disk array before streaming it out onto the DLT.
Once burnt, forever shy of vendor proprietary format backups.
Besides, my backups might outlive my vendor.
-Bennett
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Bennett Todd -
grdodson＠lexmark.com