I accidentally ran mkswap on an md raid1 device which had a mounted
ext3 filesystem on it. I also did a swapon, but I don't think
anything was written to swap before I noticed the mistake. How much
of the partition is toast, and is it something e2fsck might fix?
Luckily I have a recent full
I currently use kernel autodetection of my raid devices. I'm finding
that if I use a stock Debian kernel versus a self-compiled kernel
(2.6.15.6), the arrays md0 and md1 are switched, which creates a
problem mounting my root filesystem.
Is there a way to make the names consistent?
I'm happy to
Dan Christensen writes:
I currently use kernel autodetection of my raid devices. I'm finding
that if I use a stock Debian kernel versus a self-compiled kernel
(2.6.15.6), the arrays md0 and md1 are switched, which creates a
problem mounting my root filesystem.
Is there a way to make
Mark Hahn [EMAIL PROTECTED] writes:
Is there a way for me to simulate readahead in userspace, i.e. can
I do lots of sequential asynchronous reads in parallel?
there is async IO, but I don't think this is going to help you much.
Also, is there a way to disable caching of reads? Having to
just part of the page cache sounds too complicated to be
worth it, but clearing it all seems reasonable; some kernel developers
spend time doing benchmarks too!
Dan Christensen wrote:
I'm really surprised there isn't something in /proc you can use to
clear or disable the cache. Would
Ming Zhang [EMAIL PROTECTED] writes:
have u try the parallel write?
I haven't tested it as thoroughly, as it brings lvm and the filesystem
into the mix. (The disks are in production use, and are fairly
full, so I can't do writes directly to the disk partitions/raid
device.)
My preliminary
Ming Zhang [EMAIL PROTECTED] writes:
test on a production environment is too dangerous. :P
and many benchmark tool u can not perform as well.
Well, I put production in quotes because this is just a home mythtv
box. :-) So there are plenty of times when it is idle and I can do
benchmarks.
Here's a question for people running software raid-5: do you get
significantly better read speed from a raid-5 device than from it's
component partitions/hard drives, using the simple dd test I did?
Knowing this will help determine whether something is funny with my
set-up and/or hardware, or if
David Greaves [EMAIL PROTECTED] writes:
In my setup I get
component partitions, e.g. /dev/sda7: 39MB/s
raid device /dev/md2: 31MB/s
lvm device /dev/main/media: 53MB/s
(oldish system - but note that lvm device is *much* faster)
Did you test component device and
