HI there, I've been banging my head against the wall for a little while on this.....
I'm running TSM 5.3.4 on RedHat EL4 U4 for x86_64 (HP AMD blade server). My databases are on an HP MSA1500cs on a shelf of 14 72GB 15K drives. This is fibre attached. Now, I've been watching my I/O patterns via iostat -d -x, and it looks for all the world like it's doing serial access to the database. I'm maxing out at about 250 (4KB) reads per second, which is lame. I have 60 dbvs residing on 16 LUNs. They all used to live on a single LUN but I broke that up last night to see if the thread locking was LUN based, rather than volume (as I had originally thought). But apparently not. My DB is ~500MB, though there is a lot of cruft in there, since expirations take so long. Is this a normal access pattern? Here's an iostat, just for fun (may I recommend a mono-space font :-) ) Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/ s avgrq-sz avgqu-sz await svctm %util cciss/c0d0 0.20 42.00 25.40 6.20 321.60 385.60 160.80 192.80 22.38 0.02 0.52 0.18 0.56 sda 0.00 1.20 8.80 6.00 70.40 57.60 35.20 28.80 8.65 0.11 7.69 6.49 9.60 sdb 0.00 0.20 56.40 2.60 451.20 22.40 225.60 11.20 8.03 0.40 6.84 6.63 39.14 sdc 0.00 0.20 25.60 2.60 208.00 22.40 104.00 11.20 8.17 0.14 5.13 5.01 14.14 sdd 0.00 0.20 10.40 4.20 83.20 35.20 41.60 17.60 8.11 0.10 6.60 4.95 7.22 sde 0.00 0.20 3.80 1.20 30.40 11.20 15.20 5.60 8.32 0.03 5.36 5.24 2.62 sdf 0.00 0.20 6.00 1.80 49.60 16.00 24.80 8.00 8.41 0.07 9.26 8.74 6.82 sdg 0.00 0.40 23.00 1.00 196.80 11.20 98.40 5.60 8.67 0.17 6.97 6.88 16.52 sdh 0.00 0.20 16.80 2.80 134.40 24.00 67.20 12.00 8.08 0.12 6.26 5.99 11.74 sdi 0.00 0.20 160.40 1.80 1283.20 16.00 641.60 8.00 8.01 0.87 5.34 5.26 85.32 sdj 0.00 0.20 10.60 1.20 84.80 11.20 42.40 5.60 8.14 0.05 4.63 4.58 5.40 sdk 0.00 0.20 10.40 1.20 84.80 11.20 42.40 5.60 8.28 0.08 6.76 6.67 7.74 sdl 0.00 0.20 6.40 1.00 51.20 9.60 25.60 4.80 8.22 0.13 17.78 9.95 7.36 sdm 0.00 0.40 0.80 1.00 6.40 11.20 3.20 5.60 9.78 0.00 2.44 2.22 0.40 sdn 0.00 0.40 0.60 1.60 4.80 16.00 2.40 8.00 9.45 0.00 2.18 1.73 0.38 sdo 0.00 0.40 13.60 15.00 108.80 123.20 54.40 61.60 8.11 0.18 6.43 3.38 9.66 sdp 0.00 0.60 7.80 8.60 62.40 73.60 31.20 36.80 8.29 0.10 6.23 3.71 6.08 sdq 0.00 0.20 0.00 2.20 0.00 19.20 0.00 9.60 8.73 0.00 1.18 0.27 0.06 sdr 9.00 3309.20 82.80 73.20 39580.80 27059.20 19790.40 13529.60 427.18 15.27 97.89 6.08 94.82 sds 9.20 0.20 83.40 0.40 41272.00 4.80 20636.00 2.40 492.56 0.94 11.24 11.13 93.24 sdt 0.00 12.60 0.00 3.00 0.00 124.80 0.00 62.40 41.60 0.00 1.53 0.33 0.10 The last three LUNs are my disk pools and recovery log (all on different RAIDs). The sum of average queue length is alarmingly close to one, or put another way, alarmingly far from a big number. TCQ is set to 128 or so. The RAID supports 255 in the queue. The fiber card is a Qlogic 2312 and the driver is the standard RedHat 8.0.something (as required by IBMtape). Anyone have any thoughts, or an example iostat from a linux system where there *are* concurrent accesses going on? BTW the system is running 20ish client sessions and an expiration. Buffer pool is 2GB. Thanks for any pointers. Jason -- Jason Lee DreamWorks Animation
