Date: Tue, 1 Jun 2004 16:03:06 -0700 From: Tom Arnold <xyzzy@sysabend.org> To: performance@FreeBSD.ORG Subject: Mysql Performance issues on BSD4.9 Message-ID: <20040601230306.GN9728@moo.sysabend.org>
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I'll try to give background and be as brief as possible.
Hardware : Dell 2650, dual 2.4ghz Xeon, 3gigs RAM.
Original configuration
BSD4.8
Raid 1+0 ( or is it 0+1 ) using onboard Perc3 controller. ( 4 70gig drives )
plus an additional 70gig drive in the 5th slot. Raid was full so we added
the 5th drive and expanded the Mysql database onto it. Speed was
"tolerable"
New configuration
BSD4.9
5x140gig drives ( 15k LVD ) on same Perc3 controller.
Raid5 - Way incredably painfully slow. Slave DB would take days to catch up
with Master.
Raid0+1( or is it 1+0 damn adaptec ) + 3 seperate disks. All on Perc3
controller. - Still slow. We've used the pair of mirrored disks as the boot
disks and the mysql DB is broken up across the 3 seperates. The machine is
still sluggish. I'll paste a systat -v at the end of the message.
I'm going to apologise right off with not being more detailed about what I
mean by "slow" and "sluggish". If you can tell me more detail to look for
I'll be happy to supply.
Now, my theories for you to poke holes in.
1. The original configuration was speed-tolerable because it was basically
one large logical drive ( ignoring the standalone drive we added ) and it
was smaller drives.
2. The RAID5 configuration was dirt-slow because its Raid5 and you take a
large performance hit ( 4X normal write time? ).
3. The RAID10+3XStandalone is slow because now we have 4 seperate drives ( 1
logical 3 physical ) going via the same controller.
4. Optimal speed for this would be, say, 14 smaller ( 36 or 70gig ) drives
in RAID10. This is kind of my silver bullet solution based on experiences
running INND all those years ago.
Here's a Systat -v from the Raid10 + 3 seperate drive configuration.
Thanks!
Mem:KB REAL VIRTUAL VN PAGER SWAP PAGER
Tot Share Tot Share Free in out in out
Act 1222516 2156 1303312 3476 109292 count
All 3081632 4680 3870300 8488 pages
2085 zfod Interrupts
Proc:r p d s w Csw Trp Sys Int Sof Flt cow 3824 total
20 2105 12916 382639428 3824 5984 2109 252952 wire ata0
irq14
1239708 act 2881 bge0
irq11
15.8%Sys 1.5%Intr 1.2%User 19.6%Nice 61.9%Idl 1484452 inact 486 aac0
irq16
| | | | | | | | | | 104520 cache fdc0
irq6
========+---------- 4772 free atkbd0
irq
daefr 201 clk
irq0
Namei Name-cache Dir-cache prcfr 256 rtc
irq8
Calls hits % hits % react
72 72 100 pdwake
pdpgs
Disks aacd0 aacd1 aacd2 aacd3 acd0 fd0 md0 intrn
KB/t 59.64 64.00 64.00 64.00 0.00 0.00 0.00 197120 buf
tps 11 97 76 61 0 0 0 145 dirtybuf
MB/s 0.63 6.05 4.76 3.79 0.00 0.00 0.00 199064 desiredvnodes
% busy 1 56 57 39 0 0 0 49766 numvnodes
37974 freevnodes
--
------------------------------------------------------------------------
- Tom Arnold - When I was small, I was in love, -
- Sysabend - In love with everything. -
- CareTaker - And now there's only you... -
-------------- -- Thomas Dolby, "Cloudburst At Shingle Street" -
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