Date: Mon, 13 Mar 2000 21:47:53 -0800 From: Greg Lehey <grog@lemis.com> To: Dan Langille <dan@freebsddiary.org> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: vinum and "recovered error" Message-ID: <20000313214753.B475@mojave.worldwide.lemis.com> In-Reply-To: <200003131821.HAA40076@ducky.nz.freebsd.org>; from dan@freebsddiary.org on Tue, Mar 14, 2000 at 07:21:46AM %2B1300 References: <200003131821.HAA40076@ducky.nz.freebsd.org>
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On Tuesday, 14 March 2000 at 7:21:46 +1300, Dan Langille wrote: > Hi folks, > > This morning I found the following in my logs: > > Mar 14 00:27:42 fred /kernel: (da2:ncr0:0:4:0): READ(06). CDB: 8 18 2a 99 70 0 > Mar 14 00:27:43 fred /kernel: (da2:ncr0:0:4:0): RECOVERED ERROR info:182ae9 asc:17,1 > Mar 14 00:27:43 fred /kernel: (da2:ncr0:0:4:0): Recovered data with retries sks:80,1 > > Mar 14 01:06:16 fred /kernel: (da1:ncr0:0:2:0): READ(06). CDB: 8 4 14 a9 48 0 > Mar 14 01:06:16 fred /kernel: (da1:ncr0:0:2:0): RECOVERED ERROR info:414b0 asc:17,1 > Mar 14 01:06:16 fred /kernel: (da1:ncr0:0:2:0): Recovered data with retries sks:80,3 > > da2 is the second of a two disks which are used by vinum. Should > I be worried about the above messages? Yes, there's cause for concern, but not because of Vinum. You should check whether you have ARRE and AWRE set on the drive. If not, your disk may be on the way out. Here's information about ARRE and AWRE from "The Complete FreeBSD": Recovering from disk data errors ________________________________ Modern hard disks are a miracle in evolution. Today you can buy a 16 GB hard disk for well under $500, and it will fit in your shirt pocket. 30 years ago, a typical disk was the size of a washing machine and stored 20 MB. You would need 800 of them to store 16 GB. At the same time, reliability has gone up, but disks are still relatively unreliable devices. You can achieve maximum reliability by keeping them cool, but sooner or later you are going to run into some kind of problem. One kind is due to surface irregularities: the disk can't read a specific part of the surface. Modern disks make provisions for recovering from such errors by allocating an alternate sector for the data. IDE drives do this automatically, but with SCSI drives you have the option of enabling or disabling reallocation. Usually it is turned on when you buy them, but occasionally it is not. When installing a new disk, you should check that the parameters ARRE (Auto Read Reallocation Enable) and AWRE (Auto Write Reallocation Enable) are turned on. For example, to check and set the values for disk da1, you would enter: # camcontrol modepage da1 -m 1 -e -P 3 This command will start up your favourite editor (either the one specified in the EDITOR environment variable, or vi by default) with the following data: AWRE (Auto Write Reallocation Enbld): 0 ARRE (Auto Read Reallocation Enbld): 1 TB (Transfer Block): 0 RC (Read Continuous): 0 EER (Enable Early Recovery): 0 PER (Post Error): 0 DTE (Disable Transfer on Error): 0 DCR (Disable Correction): 0 Read Retry Count: 16 Correction Span: 41 Head Offset Count: 0 Data Strobe Offset Count: 0 Write Retry Count: 16 Recovery Time Limit: 0 The values for AWRE and ARRE should both be 1. If they aren't, as in this case, where AWRE is 0, change the data with the editor, save it, and exit. The camcontrol program will write the data back to the disk and enable the option. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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