Date: Tue, 14 Sep 2004 11:34:54 +0200 From: Eirik Oeverby <ltning@anduin.net> To: =?ISO-8859-1?Q?S=F8ren_Schmidt?= <sos@DeepCore.dk> Cc: current@freebsd.org Subject: Re: atacontrol and creating raid-1 arrays Message-ID: <4146BB3E.2070804@anduin.net> In-Reply-To: <414695D0.1020202@DeepCore.dk> References: <8AA611E5-05B1-11D9-831C-000D9335BCEC@anduin.net> <414695D0.1020202@DeepCore.dk>
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Søren Schmidt wrote: > Eirik Øverby wrote: > >> Hi, >> >> I have just done a 'cp /dev/ad4 /dev/ad6'. Those drives should be 100% >> identical (even the same drive models). Will the command >> 'atacontrol create RAID1 ad4 ad6' ruin the data on my drives? >> >> I ask because I am hoping to avoid the need for another 150 gigs of >> space just to copy the data off of the drives before creating the >> array... > > > "depends" > > Since the RAID metadata has to be put on disk it wont work if you have > that area used for real data. Depending on what controller you use the > metadata can be stored in different places. Other than that it works if > you are *sure* the disks are identical (dd with a decnet blocksize is > *much* faster tha cp). Yea, I used dd (blocksize 256kbyte proved optimal; ~40mbyte/sec) for my final operation; was testing with cp first to make sure. This is a Silicon Image SATA RAID controller which isn't supported by the ATA driver in RAID mode, so it's purely software. Which, according to another reply I got, uses the last 255 sectors on the disk. These were already free, so I just tested - seems to work fine. Fsck has no complaints. Other things I should do to verify? Thanks, /Eirik > > -Søren > > >
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