Octave,
At 12:30 PM 2/21/2001 +0100, octave klaba wrote:
>Hello,
>We use netapp for nfs server, but it is quite expensive so we
>are looking to make a fast a stable nfs server on linux (if
>is it possible).
>
>We have some question for nfs et scsi cart:
>- is there any scsi cart for linux which works like
>on netapp ? (the data are saved on the scsi cart ans
>written every 10sec. it is very quick). is eXtreme RAID 2000
>okey for this kind of project ?
I really love the eXtreamRAID cards. Sounds like your going to build a
nice box. :)
>- what is the bottleneck on nfs2/3 ? cpu ? ram ? disks ? network ?
Disks & network are the two most common bottlenecks, but it depends highly
on your usage pattern. What are you using it for? Open big huge files 1
at a time, lots of small files, a mix?
I would say fill four channels of the mylex with 3 seagate cheetah's
each. Seagate said cheetah's average about 35-40mBps/ea (though they burst
to 160 when reading from cache). That's 4x3x40 = 480mbps, then you lose a
little bit when you do RAID-10 (what I recommend -- unless your writes will
often fit in a 128mb write cache, then do RAID5).
If you can afford it, do 4 1000gbps network cards in FastEtherChannel
(called bonding/trunking) which will give you network bandwidth. After you
convert bits to bytes, this will give you 500mBps, which is what your RAID
card is capable of. (Of course, you need a switch that has 4 gbps ports
and is capable of FEC).
That may come to 10k-20k, but the speed will be incomprehensibly fast.
Memory comes in to the picture only as cache. Depending on your useage
patten, the cache may be more or less cost-effective. But RAM is cheap, so
the more you can buy the better. 256, 512, 1gb, etc.
>- on netapp we make about 2000-3000ops/sec which gives
>about 40-50Mbs on ethernet truck. do you think is it possible
>to have this kind of nfs server on linux ?
Maybe my above answer was premature. :-) Ethernet is capable of
100Mbps. Remember that is BITS. It translates to 12.5 megaBYTES per
second. That's about 1 SCSI-1 disk speed, or 1/10th the speed of ONE
modern cheetah hard drive. If you aren't going to move to at least 8-way
trunked network pipe (100MBYTES/s), or 4-way trunked Gigabit ethernet pipe
(500MBYTES/sec), then there isn't any need to invest in a nice RAID card,
since a 100mbit ethernet will bottleneck almost ANYTHING (heck, even an IDE
disk many times).
If you are looking at a small budget, look into the 3ware 6400 or
6800. Throw 4 or 8 cheap ide disks on the end of it and get about
100mbytes/sec. Combine that with 8 cheap intel pro100 cards in FEC, and
you have a 800mbps file server.
I hope that helps,
-dan
>- we use nfs2. I know nfs3 can work thought tcp (not udp).
>is it quicker ?
>
>Thanks for help
>Octave
>
>Amicalement,
>oCtAvE
>
>Illegal division by zero ?!! Aaah ? I'm _root_ !!
>-
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Dan Browning, Cyclone Computer Systems, [EMAIL PROTECTED]
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