19 reputation
7
bio website
location Sri Lanka
age 29
visits member for 3 years, 11 months
seen Oct 14 at 2:49

Hi, I am Duminda Rathnayaka. I live in Sri Lanka. My nick means Old man in English which is also my DotA alias. I play in Garena in SL room. I like to learn and I have worked with C++ and know a little Common LISP. Well, that's about it for now. I'll edit this if I feel like it later :D.


Feb
27
comment CentOS 6.0 only shows loopback address with ifconfig
I installed the drivers. But still the NICs don't show up.
Feb
14
comment Process running slow with logging in Dell R720 server
running lspci -nn | grep RAID in new server gives 03:00.0 RAID bus controller [0104]: LSI Logic / Symbios Logic MegaRAID SAS 2208 [Thunderbolt] [1000:005b] (rev 05)
Feb
14
comment Process running slow with logging in Dell R720 server
@MatthewIfe: Guess you are right. I'm tired anyway.
Feb
14
comment Process running slow with logging in Dell R720 server
and the perceived latency or slowness could be due to I/O being tied up within the kernel/OS before it even reaches the disks : How to figure out if this is the case?
Feb
14
comment Process running slow with logging in Dell R720 server
Running my program with strace -ct indicates that in the in the older server write and fadvise64 take 0usecs. But in the newer one these are 2usecs and 1usec respectively
Feb
14
comment Process running slow with logging in Dell R720 server
I updated question with comparisons of two bonnie++ runs on the two servers which also suggest that there is nothing wrong with disk. Is it safe to assume that this is a GLOG related problem?
Feb
14
comment Process running slow with logging in Dell R720 server
@Matthewlfe: I changed the path to /tmp before running the program.
Feb
14
comment Process running slow with logging in Dell R720 server
Ran your program. In the old system it takes 10.157 seconds while in the new one it takes 0.082 seconds! So, does this mean this is a GLOG problem?
Feb
14
comment Process running slow with logging in Dell R720 server
@MatthewIfe: It is of no use. Removed.
Feb
13
comment Process running slow with logging in Dell R720 server
I tried almost all of your suggestions except partition alignment I guess. Any other suggestions?
Feb
13
comment Process running slow with logging in Dell R720 server
@ewwhite: updated with /proc/meminfo
Feb
13
comment Process running slow with logging in Dell R720 server
@ewwhite: Edited the question with the benchmark program. Added cpu info. Will run bonnie++ when server is free and post comparison. Please let me know if you need any other info. ty.
Feb
13
comment Process running slow with logging in Dell R720 server
@MarkHenderson: Ok, they are 15K rpm disks. I do not understand the downvotes lol.
Feb
13
comment Process running slow with logging in Dell R720 server
After increasing the number of writes to 10x as before in the benchmark, I get 1.391s vs 10.999s in the old and new servers respectively
Feb
13
comment Process running slow with logging in Dell R720 server
tuned-adm command does not change performance. RAID is configured as RAID-0 write-back.
Feb
13
comment Process running slow with logging in Dell R720 server
@MarkHenderson: I guess you are right. Sadly, this is what is present in the quotation.
Feb
13
comment Process running slow with logging in Dell R720 server
Hi, our benchmark is pretty similar to our processes. The benchmark process was just made because one of our processes was running very slowly on the new server. After some diagnosing we found out that it was the disk writes it was stuck in. So we wrote the benchmark program to reflect that scenario.
Feb
13
comment Process running slow with logging in Dell R720 server
@MDMarra: Updated with new server disk info.
Feb
12
comment Process running slow with logging in Dell R720 server
@MarkHenderson: Yeah, but performance is the key factor here. Anyway what we are using the disk for is logs only. Our processes are CPU intensive so we want the disks to be as fast as possible.
Feb
12
comment Process running slow with logging in Dell R720 server
@MDMarra : Added lshw output on two systems. I am not sure about the last system, but in the newer one I configured RAID-0 with write-back.