On Sat, Sep 01, 2007 at 09:48:38AM -0400, Douglas A. Tutty wrote: > On Sat, Sep 01, 2007 at 12:16:00PM +1000, Alex Samad wrote: > > raid 1 / > > raid 1 /boot > > raid 5 - pv > > > > I have been looking at why not to raid 5 and I would go to raid 10 but I can > > only put 3 drives in my machine. > > > > Currently have 3x250G and am looking at getting 3x500G, if I go to mdadm raid1, > > then I have 500G safe 500G unsafe which is not really what I want. > > > > I am going to stick with the /, /boot raid1 sets. > > > > But I was thinking about setting up the rest of the space as pv's and them > > using lvm's dm-mirror to manage the mirroring of space ? then if I don't want > > any redundancy on my space I can lvcreate without dm-mirror. > > > > Any one doing this, I haven't had much experience with dm-mirror. > > my thoughts were > > > > 1 big vgroup > > and lots of lv's some with mirrors and some without ? > > > I don't see a mirror option in Etch's LV create. Okay I have lenny but I thought mirroring had been in for a while, from my man lvcreate -m, --mirrors Mirrors I haven't looked at this previously so I might be wrong. > > Here's how I would do it: > > Partition 1: 3-way raid1 64 MB for /boot I usually go for 500M, leaves me lots of room to leave stuff not sure why 3 way though, the spare space on the 3rd drive if i go 2 way i use for tmp or swap or ... > Partition 2: 3-way raid1 300 MB for / again not sure why the 3 way, currently i give 10G for this > Partition 3: 1/2 of remainder on each drive > Partition 4: the other 1/2 of remainder. > > Drives are a,b, and c. > > md0: a1, b1, c1 >> raid1 /boot > md1: a2, b2, c2 >> raid1 / > md2: a3, b4 >> raid1, as PV for LVM > md3: b3, c4 >> raid1, as PV for LVM > md4: c1, a4 >> raid1, as PV for LVM > > This way, you can still loose one drive and be safe. It gives you 750 > GB safe, 0 unsafe. nice idea to break up into little pv > > Of course, performance won't be as good as if you had 4 drives so that > you didn't have more than one busy md per drive, but this is a good > compromise. > > Why is it that you can't fit in a 4th drive? Are there only 3 bays? its a shuttle case, it only has bays for 2 hard drives, I suppose I could remove the dvd drive, but I use it a lot, so 3 is the magic number, and it worked well for me, whilst I was a raid 5 guy, but it I am thinking more back to raid1, but I would like to make the decision to mirror or not at lvcreate time not underneath been playing with some HP eva's and I like being able to set the raid level at the lun level > What about an external bay that operates at SATA speeds; look at > addonics. > > Doug. > > > -- > To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org > >
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