Question : How files transfer could be slow and normal at the same time ?
Transfer initiated from : Windows 7 computer on VLAN computer
Source : NSD share (samba from IBM GPFS) on VLAN server
Destination : Windows 7 computer on VLAN computer (the one used to initialize)
Research Track : Suppose that this can be related to the host layer of the OSI model
I'm linux Sys Admin for many clients. I use remote login, and i have'nt the possibility to test everything.
One client get a strange behaviour : From a windows 7, by opening explorer.exe and transfering one file of 1Gb (zip, iso, data, created with dd command, etc ...) from a LAN share (see configuration below) using UNC path you can have 2 differents behaviors depending of the file.
A) You can have a slow transfer rate, 7-10 Mb/s
B) You can have a normal transfer rate, 50-70 Mb/s
This transfert rate is permanent for type of file. That mean, if you try from another time at different days and hours, you will get the same result. Each time, zip file or iso file have normal transfer rate. When data file, fake file created by dd, have low transfer rate.
From another computer with same or other windows version (windows 2012 server by example), same result.
If you try with another user account, same result.
If you mount the UNC path, same result.
With antivirus activated or not
I did tests and I observe this :
Transfer from another linux on another VLAN : transfer rate is 42 Mb/s for both type of file
Transfer with winscp from windows computer on another VLAN : transfer rate is 26 Mb/s for both type of file
Transfer with cygwin from windows computer on another VLAN using SCP (ssh) : transfer rate is 47-53 Mb/s for both type of file
Transfer with cygwin from windows computer on another VLAN using mount point : transfer rate is 7-10 Mb/s for A and 55 Mb/s for B
As client use wireshark and tell to me he observe this : Wireshark show that slow transfer A is done with SMB2 protocol and normal transfer B is done with NetBios/NBSS protocol
And because my tests show SCP (SSH) the transfer rate is normal (same for all files types) I oriented my search to the top protocols of the OSI model
But i know nothing about networking / protocole.
Could someone knowledgeable help me please ?
The share : It's an IBM Spectrum Scale (new GPFS name) shared by NSD server with NFS and SMB enable on a specific VLAN server
[root@nsd ~]# mmces service list Enabled services: NFS SMB NFS is running, SMB is running # smbstatus -V Samba version 4.6.16-gpfs-56 # testparm Load smb config files from /var/mmfs/ces/smb.conf rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384) Registered MSG_REQ_POOL_USAGE Registered MSG_REQ_DMALLOC_MARK and LOG_CHANGED Registered MSG_REQ_POOL_USAGE Registered MSG_REQ_DMALLOC_MARK and LOG_CHANGED Can't find include file /var/mmfs/ces/smb.conf.0.0.0.0 Can't find include file /var/mmfs/ces/smb.conf.internal.0.0.0.0 Processing section "[home]" Loaded services file OK. Server role: ROLE_DOMAIN_MEMBER Press enter to see a dump of your service definitions # Global parameters [global] netbios name = SPECSCALE realm = xxxxxxxxxx.COM server string = IBM NAS workgroup = xxxxx preferred master = No ldap ssl = no logging = syslog@0 file max log size = 100000 add share command = /usr/lpp/mmfs/bin/mmcesmmccrexport allow insecure wide links = Yes change share command = /usr/lpp/mmfs/bin/mmcesmmcchexport clustering = Yes ctdb locktime warn threshold = 5000 delete share command = /usr/lpp/mmfs/bin/mmcesmmcdelexport lock directory = /run/gpfs-samba/lock log writeable files on exit = Yes registry shares = Yes smbd exit on ip drop = Yes smbd profiling level = on disable spoolss = Yes printcap cache time = 0 disable netbios = Yes server max protocol = SMB3_02 server min protocol = SMB2_02 unix extensions = No auth methods = guest sam winbind restrict anonymous = 2 security = ADS max open files = 20000 socket options = TCP_NODELAY SO_KEEPALIVE TCP_KEEPCNT=4 TCP_KEEPIDLE=240 TCP_KEEPINTVL=15 include system krb5 conf = No winbind max clients = 10000 winbind max domain connections = 5 winbind use default domain = Yes gencache:stabilize_interval = 3600 winbind:request profile threshold = 10 idmap config sbm : range = 1000-500000 idmap config sbm : ldap_user_dn = cn=connect,ou=Special Users,dc=xxxxx,dc=local idmap config sbm : ldap_url = ldap://master.local idmap config sbm : ldap_server = stand-alone idmap config sbm : bind_path_user = ou=People,dc=xxxxx,dc=local idmap config sbm : bind_path_group = ou=Groups,dc=xxxxx,dc=local idmap config sbm : backend = rfc2307 nfs4:acedup = merge nfs4:chown = yes nfs4:mode = simple idmap config * : rangesize = 1000000 idmap config * : range = 10000000-299999999 idmap config * : read only = no idmap:cache = no shadow:sort = desc shadow:snapdirseverywhere = yes shadow:fixinodes = yes shadow:snapdir = .snapshots readdir_attr:aapl_max_access = false fruit:veto_appledouble = no fruit:nfs_aces = no fruit:metadata = stream fruit:copyfile = yes gpfs:merge_writeappend = no gpfs:winattr = yes gpfs:hsm = yes gpfs:prealloc = yes gpfs:dfreequota = yes gpfs:leases = yes gpfs:sharemodes = yes smbd:async search ask sharemode = yes ctdb:smbxsrv_open_global.tdb = false gencache:stabilize_count = 100000 time_audit:timeout = 5000 aio_pthread:aio open = yes tdbsam:map builtin = no winbind:online check timeout = 30 groupdb:backend = tdb smbd:backgroundqueue = False notify:inotify = yes syncops:onmeta = no fileid:fstype allow = gpfs fileid:algorithm = fsname dbwrap_tdb_mutexes:* = true ctdb:registry.tdb = yes idmap config * : backend = autorid mangled names = illegal map hidden = Yes map system = Yes store dos attributes = Yes posix locking = No dfree cache time = 100 include = /var/mmfs/ces/smb.conf.internal.0.0.0.0 durable handles = No ea support = Yes force unknown acl user = Yes read only = No aio read size = 1 aio write size = 1 strict allocate = Yes vfs objects = shadow_copy2 syncops gpfs fileid time_audit [home] path = /gpfsxxxxx/home wide links = Yes smb encrypt = if_required