Differences

This shows you the differences between two versions of the page.

--- aix:aix_tuning_param [2023/03/17 00:12]
manu
+++ aix:aix_tuning_param [2024/09/04 22:47] (current)
manu
@@ Line 1: / Line 1: @@
 ====== AIX tuning performance ======
+===== Network tuning =====
+https://www.ibm.com/support/pages/node/7038687
+https://www.ibm.com/support/pages/node/6410510
+For LPARs
+<cli>
+no -p -o tcp_sendspace=1048576
+no -p -o tcp_recvspace=1048576
+no -p -o sb_max=2097152
+no -p -o rfc1323=1
+no -p -o tcp_nodelayack=0
+no -p -o sack=1
+chdev -l enX -a mtu_bypass=on
+no -p -o tcp_init_window=10
+no -p -o rfc2414=1
+no -p -o tcp_cubic=1
+</cli>
 ===== VIOS tuning =====
@@ Line 7: / Line 27: @@
 http://gibsonnet.net/blog/dwarchive/New%20FC%20adapter%20port%20queue%20depth%20tuning%20(Chris%27s%20AIX%20Blog).html
+INFO
+  On each parameter that can be changed, you can check available values:
+  lsattr -l fcs0 -a max_npivs
 ==== disk ====
+=== queue_depth ===
+For the logical drive (which is known as the hdisk in AIX), the setting is the attribute
+queue_depth, as shown in the following example:
+  # chdev -l hdiskX -a queue_depth=Y -P
+In this example, X is the hdisk number, and Y is the value to which you are setting X for
+queue_depth.
+For a high-volume transaction workload of small random transfers, try a queue_depth value of
+or more. For large sequential workloads, performance is better with small queue depths, such as a value of 4
 ==== FC adapter ====
@@ Line 17: / Line 52: @@
 Change max_npivs
 <cli prompt='#'>
-# chdev -l fcs0 -a max_npivs=128-P
+# chdev -l fcs0 -a max_npivs=128 -P
 fcs0 changed
 # exit
@@ Line 33: / Line 68: @@
 </cli>
-**adapters:**
+//adapters://
   * 16Gbps or less FC adapters: value=64
   * 32Gbps FC adapters: value=255
+=== max_xfer_size ===
+FIXME set first the xfer size on VIOS, which have to be higher or equal than LPAR vFC attribute, else the LPAR would be unable to boot
+With the default value of max_xfer_size=0x100000, the area is 16 MB, and for other allowable values of the max_xfer_size attribute, the memory area is 128 MB.
 === num_cmd_elements ===
@@ Line 76: / Line 117: @@
 === The lg_term_dma attribute ===
+For high throughput sequential I/O environments, use the start values lg_term_dma=0x400000 or 0x800000 (depending on the adapter type) and max_xfr_size=0x200000
+The AIX settings that can directly affect throughput performance with large I/O block size are
+the lg_term_dma and max_xfer_size parameters for the fcs device
 The lg_term_dma AIX Fibre Channel adapter attribute controls the direct memory access
@@ Line 97: / Line 143: @@
 ===== LPAR client =====
+==== queue_depth ====
+vSCSI adapters have a fixed queue depth of **512** command elements per adapter.
+Depending on the disk queue_depth, you can calculate the maximum LUN per adapter
+  Maximum disks per adapter = ( 512 – 2 ) / ( 3 + queue depth )
+Ex:
+  A queue depth of 32 allows 510 / 35 = 14 LUNs per adapter.
+==== VIOS vs LPAR client ====
 On which VIOS is connected a virtual FC adapter
@@ Line 140: / Line 197: @@
 secure : yes
 </cli>
+===== Test script =====
+==== for disk ====
+https://ftp.software.ibm.com/aix/tools/perftools/perfpmr/perf72/
+https://www.ibm.com/support/pages/stress-test-your-aix-or-linux-server-nstress
+<code>
+cd /usr1
+for f in 0 1 2 3 4 5 6 7 8 9
+do
+echo "Creating file: f${f}"
+dd if=/dev/zero of=f${f} bs=1m count=1024 >/dev/null 2>&1
+done
+Run(){
+ndisk64 -f f1 -C -r 100 -R -b 1m -t 20 -M 4 |grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f1 -C -R -b 1m -t 20 -M 4|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f1 -C -S -b 1m -t 20 -M 4|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f1 -C -R -r 0 -b 1m -t 20 -M 4|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f1 -C -S -r 0 -b 1m -t 20 -M 4|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f0,f1,f2,f3,f4,f5,f6,f7,f8,f9 -C -r 100 -R -b 1m -t 20 -M 4|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f0,f1,f2,f3,f4,f5,f6,f7,f8,f9 -C -r 100 -R -b 1m -t 20 -M 10|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f0,f1,f2,f3,f4,f5,f6,f7,f8,f9 -C -r 100 -S -b 1m -t 20 -M 10|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f0,f1,f2,f3,f4,f5,f6,f7,f8,f9 -C -S -b 1m -t 20 -M 10|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f0,f1,f2,f3,f4,f5,f6,f7,f8,f9 -C -R -b 1m -t 20 -M 10|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f0,f1,f2,f3,f4,f5,f6,f7,f8,f9 -C -R -r 0 -b 1m -t 20 -M 10|grep TOTALS|awk '{print $2,$3,$5}'
+ndisk64 -f f0,f1,f2,f3,f4,f5,f6,f7,f8,f9 -C -S -r 0 -b 1m -t 20 -M 10|grep TOTALS|awk '{print $2,$3,$5}'
+}
+Run
+</code>
 ===== LPM between P7 and P8 =====

wiki

User Tools

Site Tools

Differences

Page Tools