Fibre Channel (SAN)

Reply
Contributor
Posts: 21
Registered: ‎07-05-2010

Brocade 5000 - tim_txcrd_z high values

Hi all!

I have a installation with 4 Brocade 5000 whithin a SAN with a Proliant and a Hitachi USPV9990. We have some problems with the performance in the access to the Databases Filesystems in the Hitachi against 5 servers Proliant DL580 G5, with Oracle Cluster, and we don´t find the reason.

However, with the "portstatsshow" command, we find this:

vlzswfbsg1:root> portstatsshow 0
stat_wtx                3598781778  4-byte words transmitted
stat_wrx                1009317557  4-byte words received
stat_ftx                3388542767  Frames transmitted
stat_frx                1624757070  Frames received
stat_c2_frx             0           Class 2 frames received
stat_c3_frx             1624757070  Class 3 frames received
stat_lc_rx              0           Link control frames received
stat_mc_rx              0           Multicast frames received
stat_mc_to              0           Multicast timeouts
stat_mc_tx              0           Multicast frames transmitted
tim_rdy_pri             0           Time R_RDY high priority
tim_txcrd_z             211301434   Time TX Credit Zero (2.5Us ticks)
tim_txcrd_z_vc  0- 3:  0           0           211301434   0        
tim_txcrd_z_vc  4- 7:  0           0           0           0        
tim_txcrd_z_vc  8-11:  0           0           0           0        
tim_txcrd_z_vc 12-15:  0           0           0           0  
     

er_enc_in               0           Encoding errors inside of frames
er_crc                  0           Frames with CRC errors
er_trunc                0           Frames shorter than minimum
er_toolong              0           Frames longer than maximum
er_bad_eof              0           Frames with bad end-of-frame
er_enc_out              33          Encoding error outside of frames
er_bad_os               6387183     Invalid ordered set
er_rx_c3_timeout        0           Class 3 receive frames discarded due to timeout
er_tx_c3_timeout        0           Class 3 transmit frames discarded due to timeout
er_c3_dest_unreach      0           Class 3 frames discarded due to destination unreachable
er_other_discard        1           Other discards
er_type1_miss           0           frames with FTB type 1 miss
er_type2_miss           0           frames with FTB type 2 miss
er_type6_miss           0           frames with FTB type 6 miss
er_zone_miss            0           frames with hard zoning miss
er_lun_zone_miss        0           frames with LUN zoning miss
er_crc_good_eof         0           Crc error with good eof
er_inv_arb              0           Invalid ARB
open                    0           loop_open
transfer                0           loop_transfer
opened                  0           FL_Port opened
starve_stop             0           tenancies stopped due to starvation
fl_tenancy              0           number of times FL has the tenancy
nl_tenancy              0           number of times NL has the tenancy
zero_tenancy            0           zero tenancy
vlzswfbsg1:root>

This value is present in every port. Can help me about this? is Critical? how can i fixit?

Thanks in advance!!

Cesar

Super Contributor
Posts: 635
Registered: ‎04-12-2010

Re: Brocade 5000 - tim_txcrd_z high values

The device which is connected to the SAN ports is not able to handle the traffic. The san switch can not send any frames to the device because the device is not given back the buffer credits.

If this port is a storage reduce the IO queue depth on the attached servers.

Did you have any discards of class3 frames in the fabric?

Did you have IO errors on the servers?

Which ports speed did you have configured on storage and the servers?

Andreas

Contributor
Posts: 21
Registered: ‎07-05-2010

Re: Brocade 5000 - tim_txcrd_z high values

Hi Andreas,

Thanks for the explanation. We have problems with the I/O on the Storage, have a low level ( i think so) of class3 discards ( for 1.4 GB of RX, 459 disc c3 ) and have an important number of  "Invalid ordered set". I send you an example of the output, that is similar in all ports:


vlzswfbsg1:root> portstatsshow 4
stat_wtx                505705797   4-byte words transmitted
stat_wrx                2901100814  4-byte words received
stat_ftx                1557903852  Frames transmitted
stat_frx                704880639   Frames received
stat_c2_frx             0           Class 2 frames received
stat_c3_frx             704880639   Class 3 frames received
stat_lc_rx              0           Link control frames received
stat_mc_rx              0           Multicast frames received
stat_mc_to              0           Multicast timeouts
stat_mc_tx              0           Multicast frames transmitted
tim_rdy_pri             0           Time R_RDY high priority
tim_txcrd_z             159346510   Time TX Credit Zero (2.5Us ticks)
tim_txcrd_z_vc  0- 3:  0           0           159346510   0        
tim_txcrd_z_vc  4- 7:  0           0           0           0        
tim_txcrd_z_vc  8-11:  0           0           0           0        
tim_txcrd_z_vc 12-15:  0           0           0           0        

er_enc_in               0           Encoding errors inside of frames
er_crc                  0           Frames with CRC errors
er_trunc                0           Frames shorter than minimum
er_toolong              0           Frames longer than maximum
er_bad_eof              0           Frames with bad end-of-frame
er_enc_out              15          Encoding error outside of frames
er_bad_os               706638      Invalid ordered set
er_rx_c3_timeout        0           Class 3 receive frames discarded due to timeout
er_tx_c3_timeout        0           Class 3 transmit frames discarded due to timeout
er_c3_dest_unreach      0           Class 3 frames discarded due to destination unreachable

er_other_discard        61          Other discards

We are looking for the I/O of the servers.

thanks again Andreas!

Cesar

Join the Community

Get quick and easy access to valuable resource designed to help you manage your Brocade Network.