On 05/26/2009 01:39 PM, Nick Dokos wrote:
(3) FS creation time - can you create a file system in reasonable
time? (mkfs.xfs took seconds, mkfs.ext4 took 90 minutes). I think that
90 minutes is definitely on the painful side, but usable for most.
I get better numbers for some reason: on a 32 TiB filesystem (16 LUNs,
2TiB each, 128KiB stripes at both the RAID controller and in LVM), using
the following options, I get:
# time mke2fs -q -t ext4 -O ^resize_inode -E stride=32,stripe-width=512,lazy_itable_init=1 /dev/mapper/bigvg-bigvol
real 1m2.137s
user 0m58.934s
sys 0m1.981s
Without lazy_itable_init, I get
# time mke2fs -q -t ext4 -O ^resize_inode -E stride=32,stripe-width=512 /dev/mapper/bigvg-bigvol
real 12m54.510s
user 1m4.786s
sys 11m44.762s
Thanks,
Nick
Hi Nick,
These runs were without lazy init, so I would expect to be a little more than
twice as slow as your second run (not the three times I saw) assuming that it
scales linearly. This run was with limited DRAM on the box (6GB) and only a
single HBA, but I am afraid that I did not get any good insight into what was
the bottleneck during my runs. Also, I am pretty certain that most arrays do
better with more, smaller sized LUN's (like you had) than fewer, larger ones.
Do you have any access to even larger storage, say the mythical 100TB :-) ? Any
insight on interesting workloads?
Thanks!
Ric
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