-----Original Message----- From: krad [mailto:kra...@googlemail.com] Sent: 04 November 2009 09:19 To: Steve Polyack Cc: Derrick Ryalls; FreeBSD Questions Subject: Re: ZFS disk replacement questions
2009/11/3 Steve Polyack <kor...@comcast.net> > Derrick Ryalls wrote: > >> On Tue, Nov 3, 2009 at 10:21 AM, Steve Polyack <kor...@comcast.net> >> wrote: >> >> >>> Derrick Ryalls wrote: >>> >>> >>>> 1) In the event of a disk failure, how do I trace back the name such >>>> as adX to a physical drive in the enclosure? Is there a way to take >>>> the drive offline then use atacontrol to spin it down or something so >>>> it is easy to identify? >>>> >>>> >>>> >>> In my opinion you are best off using glabel(8) to give names to the >>> disks. >>> This way you can name them in a way that makes sense to you. >>> Additionally, >>> when you create the ZFS pool you will use the glabel'd names. This means >>> that the pool will still come up properly if something causes your >>> devices >>> to be numbered differently (i.e. a drive dies and you happen to reboot >>> the >>> system). >>> >>> >> >> I believe ZFS does this automatically. Supposedly, if you take a >> working set of RAIDZ drives from one machine and put it in another, >> ZFS will figure out the drives since they get labelled by ZFS >> internally. My question concerns how to identify the physical disk in >> question based on the adX or glabel name? Different name in software >> is fine, but if the drive fails I want to make sure I pull the correct >> drive. >> >> >> > This is possible, but I don't remember reading that ZFS handles this > anywhere, and I've seen glabel(8) recommended elsewhere for the same reason. > > Either way, you can add your drives one-by-one and label them on the > enclosure "arraydrive00" and then glabel the individual disks with the same > name. This way when ZFS tells you "arraydrive03" is dead/offline, you can > look at your enclosure and pull the drive with the arraydrive03 label. > > Depending on your controller it is also probably worth it to use one of >>> the >>> SATA-specific drivers in FreeBSD 8 - these are ones like ahci(4) and >>> siis(4). While the generic ata(4) driver will work for pretty much >>> everything, the updated AHCI drivers can take advantage of some more >>> features. Enable the modules at boot to use them. >>> >>> >> >> I will look into it, thanks. The machine in question is 2 year old >> hardware currently with a 3ware raid card. I will be going software >> raid only, but FreeBSD already recognizes the eSATA drive I have >> attached as a backup device so I know the O/S can at least talk to >> sata drives attached to the mobo. >> >> >> > > _______________________________________________ > firstname.lastname@example.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to " > freebsd-questions-unsubscr...@freebsd.org" > One thing to note about resilvering; unlike most raid systems zfs knows what is going on at the filesystem level as well as block level. Therefore when a drive has to be resilvered, only the data on the drive is rebuilt rather than every block as with most other raid subsystems. eg if you have a 1TB hd but only have 20 Gig of data, only 20 gig is copied/rebuilt rather than 1 TB of data if you were using gvinum/gmirror. This massively speeds up rebuild times and stress on the other drives. However the fuller the drive the less the benefits _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org" Hi All Sorry to jump in on someone else's question / answer but I have a related query. I notice the previous answer mentioned specific achi(4) driver and Freebsd 8.0 are these available in 7.2 ? Will the achi(4) driver work happily along side the ata driver. I just replaced every drive in my raidz array the dirty way as I could not see away to make the replacement drive show up without doing a reboot, would the achi(4) driver allow me to hot swap the disks in the future ? Regards Graeme _______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"