Re: Network very very slow... was iSCSI and jumbo frames

[BERTRAND Joël <joel.bertrand%systella.fr@localhost>]

RVP a écrit :
> On Mon, 8 Feb 2021, BERTRAND Joël wrote:
> 
>>     I haven't spare disks enough. Thus, I have created a disk image on a
>> Linux laptop (with an old AMD E-450), installed istgt and exported this
>> disk.
>>
>> legendre# dd if=/dev/rsd1a of=/dev/null iflag=direct bs=1m count=10000
>> 10000+0 records in
>> 10000+0 records out
>> 10485760000 bytes transferred in 156.383 secs (67051789 bytes/sec)
>>
>>     Throughput is more or less 500 Mbps on network, but there are some
>> limiting factors :
>> - CPU (but istgt only takes 60% of one thread) ;
>> - hard disk ;
>> - Ethernet adapter (Qualcomm Atheros)...
>>
>>     But 67 MBps is greater than 10 MBps I obtain with NAS.
>>
> 
> This, and the other tests show that NetBSD iscsi initiator is OK.

	Note sure, after I have poster my last message, I remember qNAP uses
iscsid as initiator and target iscsi daemon. I haven't done a test
between NetBSD initiator and iscsid linux target.

>>     I have captured tcpdump output on both adapters (I post only one
>> second) :
>> ...
>>     Often, network stops during 90 or 100 ms (see the last lines). On
>> agr0
>> (to riemann), I don't see these 'stops'.
>>
> 
> Since we are only interested in the timing and the headers, create
> tcpdump with a small snaplen like this:
> 
> tcpdump -i wm0 -s 128 -w 1.dump

	You can downloaded https://hilbert.systella.fr/public/1.dump.xz

> A snaplen of 128 is sufficient for our purposes and, compressed
> with xz(1), the entire dump of a 10GB iscsi xfer takes only ~15 MB
> with no lost packets.
> 
>>     On euclide, there is no istgt, but a iscsid (iscsid version 2.0-871)
>> and I don't understand how this daemon is started as
>> /etc/config/iscsi/sbin/iscsid.conf doesn't exists !
>> ...
>> [/] # cd /etc/config/iscsi
>> -sh: cd: /etc/config/iscsi: No such file or directory
>> [/] # ls /etc/config/iscsi/sbin/iscsid.conf
>> ls: /etc/config/iscsi/sbin/iscsid.conf: No such file or directory
>> [/] #
> 
> Try: find / -name *.conf OR find / -iname *scsi*
> on euclide. It is possible that the throttling is being done on
> the NAS for non-Linux initiators (though why it would be, I don't
> know).

	Problem. iscsid is launched with :
/sbin/iscsid --config=/etc/config/iscsi/sbin/iscsid.conf
--initiatorname=/etc/iscsi/initiatorname.iscsi

/etc/config is a symlink on /mnt/HDA_ROOT/.config/

/etc/config/iscsi/sbin/iscsid.conf  doesn't exist, but I can find
iscsi_trgt.conf in /etc/config :

[iSCSIPortal]
targetIQNPrefix = iqn.2004-04.com.qnap:ts-431p2:iscsi.
bServiceEnable = TRUE
servicePort = 3260
initiatorBitmap00 = 00000001
log = TRUE
logFlags = 1
bSupportMultiACL = 1
targetBitmap00 = 00000001
LUNBitmap00 = 00000001

[init0Info]
initiatorIndex = 0
initiatorIQN = iqn.2004-04.com.qnap:all:iscsi.default.ffffff
initiatorAlias = Default Policy
initiatorTargetBitmap00 = 00000001
initiatorLUNBitmap00 = 00000001

[InitiatorKey]
iqn.2004-04.com.qnap:all:iscsi.default.ffffff = 0

[target0Info]
targetIndex = 0
targetName = euclide
targetIQN = iqn.2004-04.com.qnap:ts-431p2:iscsi.euclide.3b96e9
targetAlias = euclide
bTargetDataDigest = FALSE
bTargetHeaderDigest = FALSE
targetStatus = 0
targetInitBitmap00 = 00000001
bTargetClusterEnable = TRUE
targetLUNNumBitmap00 = 00000001
targetLUNBitmap00 = 00000001

[TargetKey]
target_iqn.2004-04.com.qnap:ts-431p2:iscsi.euclide.3b96e9 = 0

[target0Init0Info]
targetIndex = 0
initiatorIndex = 0
bCHAPEnable = FALSE
bMutualCHAPEnable = FALSE
CHAPUserName =
CHAPPasswd =
mutualCHAPUserName =
mutualCHAPPasswd =

[LUN0Info]
LUNIndex = 0
LUNName = euclide_0
LUNPath = /dev/mapper/cachedev288
LUNMetaPath = /dev/mapper/cachedev288
LUNLVMPath = vg1-lv288
LUNSectorSize = 512
LUNCapacity = 11244416
LUNFileCount = 1
LUNThinAllocate = FALSE
LUNThreshold = -1
LUNStatus = 2
LUNBackupStatus = 0
LUNBackupPid = -1
LUNBackupJob = -1
LUNBaseType = 0
LUNInitBitmap00 = 00000001
bEnableVolumeBase = TRUE
NAANaming = qnap
bRemoving = FALSE
VSUPEnable = 0
FUAEnable = 0
LUNTargetBitmap00 = 00000001
LUNSerialNum = 46b168c9-a55f-4257-a884-2a8f2ccba65c
LUNNAA = 6e843b646b168c9da55fd4257da884d2

[LUNKey]
LUN_euclide_0 = 0

[LUN0Init0Info]
LUNIndex = 0
initiatorIndex = 0
initiatorLUNNumber = -1
accessMode = 1

[LUN0Target0Info]
LUNIndex = 0
targetIndex = 0
LUNNumber = 0
LUNEnable = TRUE

	This file seems to contain active iscsi target copnfiguration. I have
checked in /etc and I have found /etc/init.iscsitrgt.sh that shows that
iSCSI target daemon is /sbin/isns_cd

	/sbin/isns_cd is a sumlink on /usr/local/sbin/isns_cd, but I don't see
any isns_cd in ps output.

	JB