-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Ruslan Sivak Sent: Friday, May 11, 2007 3:32 PM To: CentOS mailing list Subject: Re: [CentOS] Re: Anaconda doesn't support raid10
Feizhou wrote:
Originally I had boot on 2 drives raid1, with 2 more drives being hotspares. Then I realized that this makes no sense, if
you can just
set up a raid1 with 4 drives (where each drive is a copy of each other). Didn't really know if it was supported, but looks like it works.
The entire use all four disks for /boot makes no sense if two disks belonging to the same mirror for the lvm go down. Please stop this nonsense about surviving everything to no benefit. You can
have three
disks fail and still have a working /boot. For what? _______________________________________________
Feizhou,
After thinking about it for a little bit, I see your point. If one of the arrays fails, the data drive is gone, and there is no point keeping boot after that. This means it suffices to put /boot on the first raid1 array. However, as was mentioned elsewhere in this thread, by mirroring the boot partition on all 4 drives, I don't have to worry about which order the drives are plugged in, and I can preserve disk symmetry. Since the cost of the drive is about $0.25 a GB, I think wasting the $0.10 is worth the flexibility and peace of mind.
Don't worry about it, the 4 partition raid1 makes perfect sense in your setup not for the reason you gave, but for:
1) simplicity 2) symmetry 3) flexibility 4) low to no overhead, 99.99% read partitions
It provides no downside and a lot of added bonuses.
So how is the performance on the striped LVM LVs?
Do you see the 120MB/s throughput?
Random I/O should also be as good as your drives allow.
-Ross
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