Wednesday, September 29, 2010

iPad 3G, do I need this?

Due to the uprising trend and consumer interest towards Apple's gadgets, I have decided to get myself an iPad 3G 32GB last week to catch the wave and the decision burned a big hole in my pocket. I have included the Marware Evo-Cue and a matte screen protector in the package with a total cost of about SGD1200 (MYR 2800) before the 5.5% GST refund. It is selling like hot cake in Singapore with 300-400 units sold over the weekend from a single outlet.

Well, this is my first gadget from Apple as I have been using Windows and Linux all these while. At first glimpse, the iPad is a COOL product. Booting up was a charm, ohh wait...I think there's no boot up because it booted up instantly because it doesn't has a Hard Disk. The aluminium chassis made it feel "good" on hands and the screen is nice too (no complain on this). Setting up the iPad was a charm as most of the critical settings are easily accessible via the "Settings" tab.

My iPad is being delivered with the following pre-installed apps:-
  • Calendar
  • Contacts
  • Notes
  • Maps
  • Videos
  • YouTube
  • iTunes
  • App Store
  • Safari
  • Mail
  • Photos
  • iPod
After getting the iPad from the town, I was stranded in the airport for 4 hours due to a flight delay (Tiger Airways sucks). I've decided to burn the time with the new iPad. First, I try to connect to the available Wifi AP and none of them are offering free internet services :(
So, the iPad is pretty useless without an Internet connection as I do not have apps to play with.

Then, I tried to pair the iPad up with my phone (HTC Wildfire) over bluetooth. The pairing was successful but the it can't connect to each other...Gosh...I can't transfer the photos and videos from my phone to the iPad for viewing. There are so many issue with bluetooth on the Iphone and iPad. I attempted to pair the iPad to my friend's HTC HD2 but there was no luck as well (sad). The iPad was useless for the entire duration.

I managed to hook the iPad to the Internet when I reached home. It asked me to create an iTune account before I could download any apps whereas my Android does not require me to do this. Signing up the iTunes account is quite a pain as it require a lot of personal information (data mining). They should have make the signing process as simple as signing up on Twitter, that's the standard of today!

Done with iTunes account and I downloaded Skype and eBuddy, there were no iPad version for it so I have to use the iPhone version :( Sad.........the resolution and keyboard doesn't really fit the iPad.

Next, the Safari web browser. It was nice for the first page but not after you open additional tab as the iPad does not support multitasking :( The additional tab will open but the page will reload again whenever you switch back to the previously closed tab :(

The Mail is good for iPad. Setting up Gmail, Yahoo, AOL and exchange is easy as you just need to key in your username and password. The Mail will take care the rest for you. No complain on the Mail for iPad.

Conclusion:-
In my humble opinion, this is just an overpriced luxury gadget. It doesn't really help me much in work, so I will give low scoring on practicality but it will score high on the cool factor.
I would rather spend the money to buy a small and lightweight notebook which would offer much more functionality than the iPad.

I like:
- Cool factor
- Slim
- Light
- Fast boot up
- 10 hours battery life
- Nice display

I dislike:
- Overpriced
- No multitasking
- Almost everything need to be done with iTunes
- Need to jailbreak to get extra functionality but it will void the warranty.
- Money pit as you will spend a lot of apps.
- Feel like a bigger iPhone
- No card reader slot
- No USB slot
- Non-replaceable batteries

I will provide a new update if I decide to jailbreak it later.

Tuesday, September 14, 2010

Hardware RAID vs Software RAID

On the recent few server launches, we have acquired one of the latest hardware RAID card from LSI (LSI 3ware SAS9750-4i). So, it's time for a test.

Server specs:-
1 x Intel Xeon 5504
4GB DDR3 ECC RAM

RAID hardware: LSI 3ware SAS9750-4i
Configuration: RAID5
Hard Disk: 3 x 500GB WD RE3

[root@localhost ~]# dd if=/dev/zero of=test.img count=300 bs=10M

300+0 records in

300+0 records out

3145728000 bytes (3.1 GB) copied, 106.22 s, 29.6 MB/s (writing speed)

[root@localhost ~]# dd if=test.img of=/dev/null bs=10M

300+0 records in

300+0 records out

3145728000 bytes (3.1 GB) copied, 1.18725 s, 2.6 GB/s (reading speed)

And it's time to test the rebuild speed. HOT pull out one of the Hard Disk and insert it back to rebuild. The rebuilding time was about 2hrs for 500GB drive

------------------------------------------------------------------------------------

RAID hardware: None, mdadm
Configuration: RAID1
Hard Disk: 2 x 500GB WD RE3

[test@localhost ~]$ dd if=/dev/zero of=test.img count=300 bs=10M

300+0 records in

300+0 records out

3145728000 bytes (3.1 GB) copied, 30.1198 s, 104 MB/s (writing speed)

[test@localhost ~]$ dd if=test.img of=/dev/null bs=10M

300+0 records in

300+0 records out

3145728000 bytes (3.1 GB) copied, 10.175 s, 309 MB/s (reading speed)


------------------------------------------------------------------------------------

RAID hardware: None, mdadm
Configuration: RAID0
Hard Disk: 2 x 500GB WD RE3

[user@localhost ~]$ dd if=/dev/zero of=test.img count=300 bs=10M

300+0 records in

300+0 records out

3145728000 bytes (3.1 GB) copied, 13.5305 s, 232 MB/s (writing speed)

[user@localhost ~]$ dd if=test.img of=/dev/null bs=10M

300+0 records in

300+0 records out

3145728000 bytes (3.1 GB) copied, 1.0086 s, 3.1 GB/s (reading speed)

------------------------------------------------------------------------------------

Comparison:


From the result, it show that RAID 0 has the best performance but the trade off is the reliability as it has a single point of failure comparing with RAID1 and RAID5.

Write performance is poor on RAID 5 due to the parity bit calculation and this setup is not recommended to host application which require intensive write operations. If you need good read and write performance with redundancy, consider RAID 10.

RAID1 is my favorite setup as it has the balance on all factors (space, reliability, performance) due to its simplicity, reliability and performance. RAID1 setup is recommended for simple and basic server setup.






iostat

One of the client's news portal has a surged of visitors due to a very interesting local news. The traffic doubled up overnight and the server was struggling to cope with it. The specs of the server is as below:-

Dual Xeon 5405
16GB DDR2 ECC RAM
2 x 320GB SATA 7200 (s/w RAID1)

I have tuned the webserver and mysql to allow more connections but the load was too high. The average load can go up as high as 40 during peak hours. The webserver can accept up to 352 concurrent connections now, up from 152 before the tuning. Memory usage should be still fine as only about 30MB swap being used as shown from "top" and "free".

The output from iostat is as below:-

Linux 2.6.26-2-amd64 (zz) 09/15/2010 _x86_64_

avg-cpu: %user %nice %system %iowait %steal %idle
23.95 0.00 4.44 0.80 0.00 70.82

Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 28.06 1000.72 1154.44 1459026910 1683138720
sda1 28.05 992.46 1154.38 1446969730 1683053488
sda2 0.00 0.00 0.00 4 0
sda5 0.01 8.27 0.06 12056864 85232
sdb 30.07 1078.20 1154.44 1571984044 1683138720
sdb1 30.04 1069.93 1154.38 1559927008 1683053488
sdb2 0.00 0.00 0.00 4 0
sdb5 0.04 8.27 0.06 12056720 85232
md0 163.84 1221.37 1143.97 1780718146 1667876624
md1 0.01 0.01 0.05 16216 79440

Is this bad? or normal for a 3 years old server and hard disk?

Is a hardware upgrade an imminent solution for this problem? I'm thinking of an upgrade to the latest Nehalem with SAS (Hardware RAID 10), what do you think?

Spent 3 hours fixing PHP SMTP mailer

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