--- "Callahan, Tom" <CallahanT@xxxxxxxxxx> wrote: > I understand the reason for the RAID1 devices..... I > was asking why you have > 3 devices in the RAID1 setup? RAID1 is a mirrored > configuration, requiring > only 2 disks for operation. Right. Like I indicated, I reviewed this list for suggested configurations and this is what I came up with as a result. I guess you do only need two disks, since you'll be able to recover anyway, but it seemed a simpler config with identical disk partitions and only a small amount of space wasted on one disk. > It is always wise to build in a spare however, that > being said about all > raid levels. In your configuration, if a disk fails > in your RAID5, your > array will go down. RAID5 is usually 3+ disks, with > a mirror. So you should > have 3 disks at minimum, and then a 4th as a spare. But if I don't mind the machine coming down, I don't think I need a spare? I just want to be able to rip out the bad drive, slap in a new one, rebuild, and be back in business with all my data. I don't need HA. (snip) > Another gotcha, it's usually better to use entire > disks, if you can afford > to, in an MD array. This alleviates growing pains of > having to manually > repartition if you want to grow an exisiting > filesystem. This may not make > much sense now, but once you have to do it, you'll > smack your forehead in > grief. Yes, I can see that, you instead grow by slapping in extra disks and then resizing the array. Hmm. I'll have to think about that. > > Thanks, > Tom Callahan Thanks for the advice, lots to mull over. I've got time, I'm still ddrescue'ing my crashed drive... :) Andargor > > -----Original Message----- > From: Andargor The Wise [mailto:andargor@xxxxxxxxx] > Sent: Thursday, December 15, 2005 2:45 PM > To: Callahan, Tom; linux-raid@xxxxxxxxxxxxxxx > Subject: RE: First RAID Setup > > > The RAID1 partitions are to make sure: > > 1) The machine is able to boot even if a disk is > lost > (/boot). > 2) The machine isn't brought down if a disk is lost > (swap) > > I thought about a spare drive, but I don't need high > availability. I'm satisfied with being able to > recover > my data. > > Andargor > > > --- "Callahan, Tom" <CallahanT@xxxxxxxxxx> wrote: > > > You "should" have a designated spare for RAID-5. > > > > Not sure why you have 3 disks for each RAID1, > RAID1 > > is mirror, and unless > > the third drive is a spare, it is not needed. > > > > Thanks, > > Tom Callahan > > > > -----Original Message----- > > From: linux-raid-owner@xxxxxxxxxxxxxxx > > [mailto:linux-raid-owner@xxxxxxxxxxxxxxx]On Behalf > > Of Andargor The Wise > > Sent: Thursday, December 15, 2005 2:10 PM > > To: linux-raid@xxxxxxxxxxxxxxx > > Subject: First RAID Setup > > > > > > I admit it. I'm a RAID virgin. > > > > However, after a disastrous failure of the sole > > drive > > I wasn't backing up, I decided to go RAID-5 under > > Slack 10.2 (first time ever with RAID-5). > > > > The config: > > > > Asus P5GL-MX (ICH6) mobo w/1 GB RAM, 4 x SATA > ports > > P4 3.0G/1M > > 3 x WD2000JS 200.0 GB SATA drives > > > > First, a question: the BIOS on this machine seems > to > > list the SATA ports as "third/fourth IDE > > master/slave". Further, the documentation seems to > > say > > that SATA 1/2 are "master" and SATA 3/4 are > "slave" > > (black and red connectors, respectively). > > > > My understanding is that SATA drives are each on > > separate buses. Is this because the BIOS offers a > > P-ATA emulation mode for SATA and it makes it > > "easier" > > to understand for novices to show them that way? > > > > I ask because people have said that it is not a > good > > idea to have both IDE masters and slaves on the > same > > bus as part of a RAID-5 array. I know SATA is > > different, but will using three of the SATA ports > on > > this mobo be OK? > > > > Second, after reading the excellent advice in this > > list, I decided that booting from RAID-5 might not > > be > > a good idea. So this is what I've been thinking: > > > > Each disk partitioned alike: > > 1 30MB > > 2 8GB (to allow for memory upgrades later) > > 5 rest_of_disk > > > > mds: > > md0 raid1 sda1 sdb1 sdc1 > > md1 raid1 sda2 sdb2 sdc2 > > md2 raid5 sda5 sdb5 sdc5 > > > > md0 /boot > > md1 swap > > md2 / > > > > Does this look OK? What should the stripe and > chunk > > sizes be, considering I'll be going with reiserfs? > > Typical usage: development machine, some DB apps > > with > > medium load, read-only mostly, not many writes. > Very > > few large files (such as multimedia). > > > > Or should I set up separate RAID-5's for /usr and > > /var > > as well? > > > > Lastly, can I install directly to this > > configuration, > > or should I install on a separate disk and move > > things > > into the array? > > > > Andargor > > > > > > __________________________________________________ > > Do You Yahoo!? > > Tired of spam? Yahoo! Mail has the best spam > > protection around > > http://mail.yahoo.com > > - > > To unsubscribe from this list: send the line > > "unsubscribe linux-raid" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at > > http://vger.kernel.org/majordomo-info.html > > > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! 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