Comments (5) 日子過得真快，記得3年前的這個時候，膽粗粗地在討論區開始了我的第一貼後就踏上了這個奇妙的快樂網球旅程。
過去的一年裡，認識了40多位新的朋友﹔第一次因為受傷而休息了1個半月﹔認識了一位球技高超的鄰居﹔終於更換了跟隨自己20多年POG球拍﹔發球和反手有了明顯的進步(在放鬆心情和沒壓力下，哈哈﹔每個星期有了班固定的打球朋友﹔多舉辦了刺激的男單和混雙。
另外就是身體也比以前強壯了不少，Touch Wood整年沒有感冒傷風過，雖然是瘦了些，但這應該是正常的，因為目睹多數每星期打2至3次網球的師兄弟們都很苗條，哈哈。
總得來說我很感激上天給我的這些機會和會更加珍惜這些難得的緣份。
再次謝謝大家，希望今後的日子有更多的朋友和我一齊來享受Happy Tennis。
Some interesting statistics:
Courts Booked: ~185場
Tennis Balls: 62罐
Restring: 5次
Finally I’ve completed the desktop migration to Dell Optiplex 990 SFF after using the antique Asus P2BD for 13 years, and currently I’m enjoying every moment with the new PC.
Today I suddenly realized my Dell Ultrasharp 2007FP (in 1600 x 1200 mode using DP to DVI) isn’t working properly with its Power Saving feature. The LCD Monitor power indicator button should become Amber (Less than 2 W), instead it stays as Green all the time with “No DVI-D Cable” signal floating around the screen. This means the LCD is still drawing full power (about 75W) and burning every pixel even the screen is blank.
Searched many places on the net and ended in vain mostly (in fact many people having problem with Dell’s LCD monitor not able to resume from Power Saving Mode, but this is not my case), Then I tried to connect my screen to a VGA and the power saving function worked perfectly, hum…I know it’s nothing to do with Windows 7 Power feature, definitely not my Ultrasharp 2007FP’s problem, so this leaves only one possibility, it must be the cable!
So I put back the original Dell DP to DVI Adapter with a DVI (male) to DVI (male) cable, guess what? The screen shows Going into “Power Saving Mode” and then the power button went to Amber, ha, now we are on the right track.
I couldn’t wait to solve this problem and I really don’t like the messy combination of Dell DP to DVI Adapter with the extra DVI cable. What I need is a simple DP to DVI cable that works! So I rushed to the computer store and bought me another little bit expensive DP to DVI cable (about USD15 and kind of hard to get only one shop got it) and rushed back, crossed my finger when turned on the monitor power.
No DVI-D Cable again and worst, my screen won’t come back even I moved the mouse, Shoot! Am I a victim of the infamous Dell LCD monitor isn’t being able to resume to normal in Power Saving Mode?
Luckily this isn’t the case after I restarted my PC, everything worked just as expected, my Dell Ultrasharp 2007FP worked as designed, Going into Power Saving Mode, then all lights become Amber, yeah!
So a cheap quality cable wasted at least 5-6 hours of my precious time searching for solution. I really hated it while I am searching for the answer, in fact, this is part of my daily job, ie, always involving in PROBLEM SOLVING in all kind of things, and I love it so much after finding the answer, kind of contradicting right? Yeah, dude that’s life unfortunately!
This little trick only works for entry level hacker, it won’t stand a chance with advanced hacker, not to mention those DDOS with pure bandwidth consumption (I don’t think there is a way to mitigate this at all anyway, if you do, pls drop me a line).
First I tried the following intuitive command on Windows Server 2003 and found out it doesn’t work, somehow, Windows doesn’t allow route to 127.0.0.1.
route add DDOS_IP 255.255.255.255 127.0.0.1
* Assume DDOS_IP is the DDOS source IP Address.
The solution is to create a loopback (ie, fake) NIC by go to Control Panel, then Add Hardware > Network Card > Microsoft Loopback Adapter.
From Properties, Remove everything and leaving only TCP/IP, assign it a fake IP (say 192.168.80.8), disable WINS of course.
Finally, simply route the crap to this fake destination
route add DDOS_IP MASK 255.255.255.255 192.168.80.8
If you want to permanently add this DDOS IP, use route add –p parameter.
To remove it, type “route delete DDOS_IP”.
In additional, if you want to block the whole C-Class (ie, 256 IPs, mask /24) of DDOS source, then use:
route add DDOS_IP MASK 255.255.255.0 192.168.80.8
For example: route add 202.128.110.0 MASK 255.255.255.0 192.168.80.8
Finally, how do you know which IP is DDOS your server? Well, if you find a IP with many LAST_ACK from netstat, then this indicates a very high possibility that the IP is the DDOS attacker.
Examples
To display the entire contents of the IP routing table, type:
route print
To display the routes in the IP routing table that begin with 10., type:
route print 10.*
To add a default route with the default gateway address of 192.168.12.1, type:
route add 0.0.0.0 mask 0.0.0.0 192.168.12.1
To add a route to the destination 10.41.0.0 with the subnet mask of 255.255.0.0 and the next hop address of 10.27.0.1, type:
route add 10.41.0.0 mask 255.255.0.0 10.27.0.1
To add a persistent route to the destination 10.41.0.0 with the subnet mask of 255.255.0.0 and the next hop address of 10.27.0.1, type:
route -p add 10.41.0.0 mask 255.255.0.0 10.27.0.1
To add a route to the destination 10.41.0.0 with the subnet mask of 255.255.0.0, the next hop address of 10.27.0.1, and the cost metric of 7, type:
route add 10.41.0.0 mask 255.255.0.0 10.27.0.1 metric 7
To add a route to the destination 10.41.0.0 with the subnet mask of 255.255.0.0, the next hop address of 10.27.0.1, and using the interface index 0×3, type:
route add 10.41.0.0 mask 255.255.0.0 10.27.0.1 if 0×3
To delete the route to the destination 10.41.0.0 with the subnet mask of 255.255.0.0, type:
route delete 10.41.0.0 mask 255.255.0.0
To delete all routes in the IP routing table that begin with 10., type:
route delete 10.*
To change the next hop address of the route with the destination of 10.41.0.0 and the subnet mask of 255.255.0.0 from 10.27.0.1 to 10.27.0.25, type:
route change 10.41.0.0 mask 255.255.0.0 10.27.0.25
The demo does look a lot like a transformer in action, it’s so cool!
Oh…it’s the world’s 1st server with PCIe 3.0 (1GB/s bandwidth?) and DL380 surprised me with a newly designed nice looking bezel (finally!), but it looks like a Poweredge now. 
That’s why I love the latest innovative network, server and storage technologies, they have always been my biggest hobby and toy, so much fun to learn and play with.
Previously I’ve mentioned the followings regarding the latest DDR3L RAM:
It’s nice to have that 20% electricity saving, but when you add 2DPC (2 DIMMs Per Channel), your nice 20% power saving (ie, 1.35V) will be disabled automatically (ie, raise to 1.5V instead). However the good part is you still get that 1333Mhz bandwidth with 2DPC. DDR3L 1.35V will only apply when it’s in 1DPC mode.
What I’ve found out today during the server upgrade is the above may not be always true.
May be it’s related to the Poweredge BIOS that I’ve updated sometimes ago as it may contain the changes now allowing 2DPC operating at 1.35V Low Voltage. (may be even 3DPC)
The server is Poweredge R610 with 1 CPU Xeon E5620 (32nm, 12M Cache, 2.40 GHz, 5.86 GT/s, max supports DDR3-1066). After I filled up all the available 6 DIMMS, (ie, 3 Channels, 2 DIMMS per channel), I saw during the rebooting screen, it showed DDR- 1066Mhz and 1.35V, This is Great! I was expecting to see 1.5V as this happens to my R710 when putting 2DPC, it automatically raised to 1.5V, probably will go down to 1.35v if I upgraded the BIOS for that R710.
Finally, I located this interesting White Paper about Samsung’s DDR3L RAM, the result shows even with 3DPC at 1.5V, you can still save up to 50% of the total power consumption by using DDR3 Low Voltage RAM. There are also many other interesting technical insides regarding the benefits using DDR3L RAM.
The other thing is the RAM Upgrade KIT somehow did’t come with Heatsink, strange.
What you are seeing in the above picture is a direct comparision of two ALMOST IDENTICAL 4GB RAM, even the IC chipset part number is almost identical except a single character difference.
The one on top is used in Desktop (Optiplex 990 SSF), I bought it in a local computer shop for under USD20, and the other is for this server upgrade (ie, Poweredge R610).
As you can see there are two extra chips in server ram (hence ECC and Buffer), and note the “L” indicates this server RAM is a Low Voltage version.
I also noticed the desktop ram label says it’s 10600U and server one says 10600R, ha…here is the fun part, I am sure this means U-DIMM (as Un-Buffered) and R-DIMM (as Registered & Buffered), so what does it mean or why this is so important?
Well, technically you can fit a cheap U-DIMM (about USD20 per 4GB DIMM) into any Poweredge R2xx, R6xx, R7xx, R8xx, R9xx, of course, there is a limit when using U-DIMM, maximum you can use is 24GB, so that’s about 6 DIMMS x 4GB U-DIMM.
And the saving is Huge, for some may be (as USD120 for U-DIMM vs USD420 for R-DIMM), that’s USD20 for a 4GB U-DIMM that you can buy from any local computer shop as they are simply a desktop RAM, comparing to USD70 for the equivalent R-DIMM.
Of course, I will still choose R-DIMM, you may ask for maximum 24GB, why pay that extra USD300-315 for ECC Reg RAM? Well…RAS and reliability is the number one factor in data center business, and not to mention the expandability, so Why NOT?
I thought it’s only available in FW 5.1 with ESX 5.0 or above (in fact, it turns out this EQL feature is not even ready yet till Q2/Q3 2012), and I am surprised to find out the following today somewhere on-line.
Still I do not have the courage to do this in my production, it’s just too scary, better just Storage VMotion from one datastore (ie, EQL volume) to another datastore and then remove the old dirty volume to claim space.
Shrinking is only supported in EqualLogic firmware version 3.2.x or greater. Shrinking a Thin Provisioned volume is only supported in V4 or higher. For v3.2, you can however, convert a TP volume to a standard thick volume and then resize it, assuming there is space available to do so.
CAUTION: Improperly shrinking a filesystem can result in data loss. Be very careful about shrinking volumes, and always create snapshots to fall back to in the event of a problem.
To shrink a volume you must first shrink the file system and partition. While there are a few Operating Systems, like Windows 2008 for example, which support this natively, most do not. For Windows NT, 9x,XP, W2K3, you need to use a tool such as partition magic, partition commander, or similar tool. We do not test these tools in house, so we cannot make any statements about how well they work.
WARNING: be certain that you are shrinking the volume to slightly larger than what you have reduced the filesystem/partition size to. Shrinking a volume to be smaller than the partition/filesystem “WILL” result in data loss, i.e., if you reduced the filesystem to 500G, shrink the EQL volume to 501GB.
Always create a snapshot before attempting any resize operation. Shrink the file system & partition slightly more than you intend to shrink the volume to avoid rounding or other math discrepancies.
The volume will need to be offline to shrink the volume, og off or shutdown the server(s) connected to that volume first.
The Shrink command is a CLI only option. You have to first select the volume (covered in the CLI manual available on the FW download page).
GrpName> vol sel
GrpName(volume_volume_name)> offline
GrpName(volume_volume_name)> shrink
GrpName(volume_volume_name)> online
Just found Storage Response Time Monitor 10 mins ago, downloaded and installed it and love it at the first sight! It correctly shows me the real-time break down of each Equallogic volume latency and what’s more, it lists the top 5 BUSIEST VMs with IOPS number for that particular volume in one single window.
Having trouble with storage latency issues? Seeing your response times getting slower and slower? Download SolarWinds Storage Response Time Monitor and start tracking those sluggish VMs. Storage Response Time Monitor shows the top host to datastore total response times and a count of additional high latency offenders. Keeping track of your storage response times has never been easier.
Storage Response Time Monitor Highlights:
- Get at-a-glance insight into host to datastore connections with the worst response times, and the busiest VMs using those connections
- See a breakdown of the datastore including type and device versus kernel latency
Amazing, someone actually made such an interesting blog collecting all the related articles he could find on the net, listing out all the pros & cons of each vendor, for me, of course I bias towards Equallogic, but it’s nice to see such in depth comparison.
This happened two days ago and followed by a very happy ending.
Around 8AM, I received an SMS alert saying one of the email server isn’t responding, then it followed with many emergency calls from clients on that email server (obvious…haha).
I logged into vCenter and found the email server had a question mark on top of its icon, shortly I realized the EQL volume it sits on is full as SANHQ also generated a few warning as well the previous days, but I was too busy and too over confident to ignore all the warnings and thinking it may get through over the weekend.
The solution is quite simply. First increase the Thin Provisioned EQL volume size, then extend the existing volume in vCenter, next simply answer the question on the stunned (ie, suspended) VM to Retry again, Woola, it’s back to normal again, no need to restart or shutdown the VM at all.
This is really beautiful! I was a bit depressed when knowing it will only work with ESX 5.0 previously and this was also confirmed by a Dell storage expert, then found out the The VMware’s Thin Provision Stunning feature will work with ESX 4.1 again the other day from Dell’s official document, I was completely confused as I do not know who’s right until two days ago.
FYI, I had a nasty EQL Thin Provisioned volume issue last year (EQL firmware was 4.2), the whole over-provisioned thin volume simply went offline when it reached the maximum limit and all my VMs on that volume crashed and need to restart manually even after extending the volume in EQL and vCenter.
No more worries, thank you so much Equallogic, you really made my day!
Finally, some those who may be interested to know why I didn’t upgrade to ESX 5.0? Why? Why should I? Normally I will wait for a major release like ESX 3.5 or ESX 4.1 before making the big move.
There is another issue as the latest Veeam Back & Replication 6.0 still have many minor problems with ESX 5.0 and frankly speaking, I don’t see many advantage moving to ESX 5.0 while my ESX 4.1 environment is so rocket solid. The new features such as Storage DRS, SSD caching or VSSA are all minor stuffs comparing with VAAI and iSCSI multipathing, thin provisioning in ESX 4.1. In additional, the latest EQL firmware features always mostly backward compatible with older ESX version, so that’s why I still prefer to stay at ESX 4.1 at least for another year.
Oh…one thing I missed that is I really do hope EQL firmware 5.1 Thin Reclaim can work on ESX 4.1, but it seemed it’s a mission impossible, never mind, I’ve got plenty of space, moving a VM off a dirty volume isn’t exactly a big deal, so I can live with it and manually create a new clean volume.
Update Jan 17, 2012
Today, I received the latest Equallogic Newsletter and it somehow also indicates this VMware Thin Provisioning Stun feature is supported with ESX 4.1, hope it’s not a typo.
Dell EqualLogic Firmware Maintenance Release v5.1.2 (October 2011)
Dell EqualLogic Firmware v5.1.2 is a maintenance release on the v5.1 release stream. Firmware v5.1 release stream introduces support for Dell EqualLogic FS7500 Unified Storage Solution, and advanced features like Enhanced Load Balancing, Data Center Bridging, VMware Thin Provisioning awareness for vSphere v4.1, Auditing of Administrative and Active Directory Integration. Firmware v5.1.2 is a maintenance release with bug fixes for enhanced stability and performance of EqualLogic SAN.
Update Mar 5, 2012
I found something new today that Thin Provisioning Stun is actually a hidden API in ESX 4.1 and apparently there are only two storage vendors support it in ESX 4.1, one being Equallogic, no wonder this feature worked even with firmware v5.0.2, as I thought at least v5.1 is required. Thanks EQL, so this gives me a bit more time to upgrade to FW5.1 or even FW5.2.
Thin Provisioning Stun is officially a vSphere 5 VAAI primitive. It was included in vSphere 4.1 and some array plugins support it, but it was never officially listed as a vSphere 4 primitive.
Out of Space Condition (AKA Thin Provisioning Stun)
Running out of capacity is a catastrophe, but it’s easy to ignore the alerts in vCenter until it’s too late. This command allows the array to notify vCenter to “stun” (suspend) all virtual machines on a LUN that is running out of space due to thin provisioning over-commit. This is the “secret” fourth primitive that wasn’t officially acknowledged until vSphere 5 but apparently existed before. In vSphere 5, this works for both block and NFS storage. Signals are sent using SCSI “Check Condition” operations.
VAAI Commands in vSphere 4.1
esxcli corestorage device list
esxcli vaai device list
esxcli corestorage plugin list
