Date: Sat, 26 Nov 2005 15:22:37 -0500 (EST) From: user <user@dhp.com> To: Herve Boulouis <amon@sockar.homeip.net> Cc: freebsd-scsi@freebsd.org Subject: Re: configuration choices with Dell CERC (adaptec 2610SA) Message-ID: <Pine.LNX.4.21.0511261520500.8180-100000@shell.dhp.com> In-Reply-To: <20051126194152.GA594@ra.aabs>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, 26 Nov 2005, Herve Boulouis wrote: > Le 26/11/2005 14:17, user a =E9crit: > >=20 > > Read caching: yes/no (default is yes) > >=20 > > (read caching does not rely on a battery, and is completely "safe", > > right? I am going to set this to "yes", however I wonder - why would > > anyone _ever_ set it to "no" ?) > =20 > You usually want to disable read caching on all aac based adaptec raid > controllers because it decreases performance. >=20 > > Write caching: enable/disable > > > > (this is the one that can get you into trouble if the system loses powe= r > > before a write is committed to disk, and the battery is dead, right? I= am > > going to set this to "disable" because I do not think the 2610SA has a > > battery ... right ?) >=20 > If your server is plugged on a UPS you can safely enable it, it's quite > a performance gain. One other clarification - I have the option to turn write caching on and off when I create the array (I am turning it ON now for the array based on your opinion) ... but I also have an option in the adaptec bios to turn write-caching on for each specific disk drive. I have also turned this on. Are these seperate settings, or are they redundant ? (or does write caching for the array _depend on_ having write caching for each drive turned on ?) thanks.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.LNX.4.21.0511261520500.8180-100000>