Hi,
I have 7609-S chassis with RSP720-3C-GE installed as PE router. DRAM installed is about 1GB. Few days ago I noticed that the I/O memory usage is considerably high which is about 68-70%. At first, I consider it as having memory leak bug CSCtr34960 that I previously raised to TAC with my SUP720-3BXL supervisor. The solution for CSCtr34960 with SUP720-3BXL is IOS upgrade.
With the TAC information for memory leak in SUP720-3BXL, I tried to also upgrade the IOS of RSP720-3C-GE.
Before upgrade: RSP720-3C-GE with SRE4
After upgrade: RSP720-3C-GE with 15.2(2)S
Directly after upgrade, I noticed that the I/O memory usage is still considerably high and increasing about 1-2% compared with before upgrading. Here is the output:
cs-belanti.1#sh mem stat
Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)
Processor 13C862C4 674733372 253148764 421584608 420232456 421147972
I/O 3C000000 67108864 46746960 20361904 20361904 20347964
I checked into my other devices with SUP720-3B, SUP-720-3BXL, and RSP-720-3C-GE I/O memory status and found that all RSPs are having I/O memory utilization above 60%. SUP720-3B and 3BXL only use about 25% of I/O memory. I have about 20 RSPs and about 50SUPs so I think the sample would be enough to determine that all RSPs consume very large I/O memory.
I have make sure that CPU is still underutilized (<10%) and having no buffer issue:
cs-belanti.1# sh buffers
Buffer elements:
855 in free list
29037294 hits, 0 misses, 617 created
Public buffer pools:
Small buffers, 104 bytes (total 1024, permanent 1024):
1017 in free list (128 min, 2048 max allowed)
13181038 hits, 0 misses, 0 trims, 0 created
0 failures (0 no memory)
Medium buffers, 256 bytes (total 3000, permanent 3000):
3000 in free list (64 min, 3000 max allowed)
271142 hits, 0 misses, 0 trims, 0 created
0 failures (0 no memory)
Middle buffers, 600 bytes (total 512, permanent 512):
511 in free list (64 min, 1024 max allowed)
65503 hits, 0 misses, 0 trims, 0 created
0 failures (0 no memory)
Big buffers, 1536 bytes (total 1000, permanent 1000):
1000 in free list (64 min, 1000 max allowed)
1169354 hits, 0 misses, 0 trims, 0 created
0 failures (0 no memory)
VeryBig buffers, 4520 bytes (total 10, permanent 10, peak 23 @ 16:10:46):
9 in free list (0 min, 300 max allowed)
25067 hits, 7 misses, 13 trims, 13 created
1 failures (0 no memory)
Large buffers, 9240 bytes (total 8, permanent 8, peak 12 @ 14:48:33):
8 in free list (0 min, 10 max allowed)
136252 hits, 2 misses, 4 trims, 4 created
0 failures (0 no memory)
Huge buffers, 18024 bytes (total 2, permanent 2):
2 in free list (0 min, 4 max allowed)
0 hits, 0 misses, 0 trims, 0 created
0 failures (0 no memory)
Can anyone help me in this case? Is I/O memory usage above 60% in an underutilized 7600 router with RSP normal?
It seems that we cannot manually determine the size of I/O memory in 7600 since the value given should be the best practice.
Thanks,
Sincerely,
Jeffry
