performance tuning of iSCSI and Dell MD3000i

[Miroslav Lachman]

Hi,

[1]
I am using iSCSI Initiator 2.2.3 (on 7-STABLE amd64) and Dell MD3000i as 
storage for server distributing downloads of large files (10-200MB) 
through Lighttpd daemon.
Is there any tips for performance tuning?

My iscsi.conf is:
styx_storage_1 {
         initiatorname   = iqn.2005-01.il.ac.huji.cs::dust.example.com
         TargetName      = 
iqn.1984-05.com.dell:powervault.md3000i.60026b900042587b000000004ae58efc
         TargetAddress   = 192.168.130.101:3260,1
         tags            = 64
}

Lighttpd is serving about 200-300 client connections at speed 220Mb/s it 
is about 215Mb/s on iSCSI network interface to MD3000i. (iostat showed 
100% busy of da0)
Is it really maximum achievable speed on this type of iSCSI storage? 
(made of 4 SATA drives in RAID5)
Or can it be better with some tuned settings?

Have anyone experiences with MD3000i - if I add more disk drives in to 
RAID5, will it help? How much?


[2]
Is somewhere final rc script for iscsi initiator which can be used to 
mount filesystem from iSCSI target at boot time by standard rc 
procedure? Why is it not included in the base system if iscsi_initiator 
is there for a long time?


[3]
And one other thing, I got following error logged in messages after 2 
days of running some performance tests:

Jan 19 05:36:50 dust kernel: >>> so_recv: have a problem, error=0
Jan 19 05:36:50 dust kernel: isc_in: sp->soc=0xffffff0028f14000
Jan 19 05:36:50 dust kernel: 0] isc_in: terminated, flags=39f so_count=2 
so_state=2000 error=2080 proc=0xffffff0005ab1910
Jan 19 05:36:50 dust kernel: 0] isc_in: pid=963750 s]i gin_alfeudl(l3f0e)atu
Jan 19 05:36:50 dust kernel: r0e]:  ifslca_gi=n0:
Jan 19 05:36:50 dust kernel: dropped ISC_CON_RUNNING
Jan 19 05:36:50 dust iscontrol[96375]: trapped signal 30
Jan 19 05:36:52 dust kernel: 0] i_send: len=492 ahs_len=0 ds_len=441 
buf=444 at 0xffffff0007068000
Jan 19 05:36:52 dust kernel: 0] i_setopt: maxRecvDataSegmentLength=65536
Jan 19 05:36:52 dust kernel: 0] i_setopt: opt.maXmitDataSegmentLength=65536
Jan 19 05:36:52 dust kernel: 0] i_setopt: opt.maxBurstLength=131072
Jan 19 05:36:52 dust kernel: 0] i_setopt: 
opt.targetAddress='192.168.130.101'
Jan 19 05:36:52 dust kernel: 0] i_setopt: 
opt.targetName='iqn.1984-05.com.dell:powervault.md3000i.60026b900042587b000000004ae58efc'
Jan 19 05:36:52 dust kernel: 0] i_setopt: 
opt.initiatorName='iqn.2005-01.il.ac.huji.cs::dust.example.com'
Jan 19 05:36:52 dust kernel: 0] i_setopt: opt.headerDigest='None'
Jan 19 05:36:52 dust kernel: 0] i_setopt: opt.dataDigest='None'
Jan 19 05:36:52 dust kernel: 0] i_fullfeature: flag=2
Jan 19 05:36:52 dust kernel: 0] ism_restart: restart ...
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a30e4
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a30e5
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a30e7
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a30ea
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a30eb
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a30f3
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a30f4
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3111
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3117
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3118
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3119
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a311a
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a311d
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a311e
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3120
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3121
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3123
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3124
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3126
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3127
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3128
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a3129
Jan 19 05:36:52 dust kernel: 0] iscsi_requeue: last=30a30e4 n=30a312a
Jan 19 05:36:52 dust kernel: 0] ism_restart: restarted sn.cmd=0x30a312b 
lastcmd=0x30a30e4

Then transfer of files continued at slightly lower speed than before.

Miroslav Lachman