From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: Date: Sat, 23 Sep 2006 11:04:46 -0400 From: "Russ Cox" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu> Subject: Re: [9fans] Re: venti+fossil problems on new install In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200609230751.aa34074@salmon.maths.tcd.ie> Topicbox-Message-UUID: c01bbc06-ead1-11e9-9d60-3106f5b1d025 All this speculation about DMA and boot sectors and whether Plan 9 is actually installed is really enthralling, but it's not John's problem. John's problem is that reading or writing a certain part of the disk causes an i/o error that the disk driver can't seem to recover from. It could be a disk problem but it could also be a driver problem. Without making kernel changes to turn on some debugging prints in the sdata driver, it's hard to say which. Probably the SATA card or disk is slightly non-standard and behaving in a way that confuses the driver. You might try running a whole disk diagnostics program from the manufacturer (the kind that come on bootable media) just to double-check that the disk itself doesn't have some bad sectors. But it really sounds like the disk just doesn't behave quite according to expectations. The reason /dev/sdC0 looks okay after the i/o error is that it is updated by a user-level program that runs at boot (disk/prep -p and disk/fdisk -p), so even if the disk goes south underneath, the kernel will remember the configured partitions. Russ