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Showing posts from May, 2009

SATA disk shelf research

I'll compile it here for my reference really.

We use the Perc 5/e card in two servers - we'll use one to attach to our current MD1000 - I'm checking around for a better alternative to another MD1000 - the lowest price I've seen for an MD1000 is $1200 on Dell's Outlet site. Needless to say, it disappeared quite quickly. Now that we have a US address to ship to, that site can be used!

The current MD1000 will be filled with our existing 300GB 15k SAS disks, and probably set up for RAID10 or 50. It'll house our ESXi test environments in two arrays I would guess. We need another one for other purposes.

The purpose of the second unit: mass storage array for temp files, archives, miscelaneous files, and backup-to-disk. The more space and spindles, the better, however, price does factor into things. Another option would be to run openFiler alongside it. Have to explore that.

Here are the current options:
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Used Dell MD1000 (s…

iSCSI and MPIO and VMs, oh my.

Connecting a 2008 ESX VM guest to a raw LUN on the SAN.

Acronyms. Sheesh.

Set up the VM.
Install MPIO (requires a reboot).
Open up the iSCSI initiator in cpanel.
Change the firewall settings to allow pinging back and forth - required for MPIO.
Install DSM from the EqualLogic disk.
Ensure SAN nics are installed to the VM and configure with IP and subnet mask.
Under the iSCSI initiator, go to Discovery, and add your group IP under portals.
Choose Targets, then log on to your lun of choice.
When logging on, choose 'use multipathing' and 'restore connection'. Click advanced.
Select 'iSCSI initiator', the first nic IP, and the destination (group ip), no other options necessary.
Do the same for the second nic IP.
If you click 'details' on the lun you've targeted, you should see two connections.
Ensure they are set to round robin.
Check the network interface monitor on the SAN console - should see two interfaces active while transferring data.

SANs are different Part 2

Well, we bought one. The EqualLogic PS6000XV, the 450GB flavour.

We're on our demo unit (a 5000-series) until the new one arrives, at which point we'll join the new one to our group and 'evacuate' the data over. Pretty nifty. That feature alone saved EQL the sale over the EMC AX-4 a company was trying to get us into. Sadly, they could not get us a demo unit in time, so we could not test in time. Ah well. We all really like the EQL solution, and features. Since we're close to Dell we got a pretty nice price as well.

Amusingly enough, the only complicated part of the SAN is the rack mounts - they are terrible! Or rather, the diagrams are...photocopied CAD diagrams at that.

We're using these specs to judge because the critical loads are SQL I/O, and the average request is around 50kb.

Our performance numbers looked something like this, keeping in mind this is the 10k PS5000. All are random reads, 64 threads to a depth of 128. Shown is the block size and max …

DCPromo

We're virtualizing our DCs today.

Process:

Setup new 2k8 vm template.
Copy.
Get VM set up and newsid.exe it, rename.

For the domain:

Need to transfer the 5 FSMO roles.
Use ntdsutil and the GUIs to make sure.
ntdsutil - connect to the server you want to make master
- transfer the roles, only seize roles if you've messed up and forgotten something, or you've had the server crash.
- see here for details: http://support.microsoft.com/kb/324801

Once DHCP and DNS are setup and running on the two VMs, take one physical DC offline by doing DCPromo, then unjoining (is there a proper term for that?) from the domain, then unplugging the network cable.
Take the IP address of the decomissioned DC and set up the VM DC to use it. Reboot the VM DC.
Should be working now - check that DHCP leases are being created, and that DNS reports the correct IPs.

Exchange will need to be rebooted to take into account the new DCs for 'configuration manager'. You can try and change this manually, but i…

SANs are different

Simple title...but to me, it makes sense, especially when we're talking about disk performance.

My understanding of disk performance has changed dramatically these last few days. I went into it believing that it was all about disk speed and max throughput, so an array of 6 15k SAS disks in RAID5 was fast to me, and there was no way anything SATA could equal it.

However, when you speak of IOPS (I/O per second) - a term thrown around like jellybeans by SAN sales people - it really comes down to spindles, as in, the number of disks you have.

A good metaphor someone told me was to think of a library. It's a small thing for one person (one disk) to get six books that are on the same shelf. It's even easier for six people (the six SAS disks) to look for 6 books, especially if they are all together. However, in an SQL environment, requests are asking for data all over the place.

So, if you then think of one person trying to get six books from all corners of the library, it makes …

Jetta front suspension almost done

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I upgraded, as mentioned below, some of the Jetta's front suspension the other day. After realizing that my Princess Auto spring compressors were universal, and needed some customization to work properly in the Jetta wheel wells (cut off about 4" on each one), the struts went in nice and easy! The front sway-bar bushings were super-easy to replace as well.

You can see in the one picture how I got the strut mounts off and then re-torqued.

While I was waiting for H to come by with a bolt-out kit (that proved fruitless against the might of the dogbone mount corrosion), I decided to get rid of the rest of the skunk smell (see short story). It was awful, and permeated the garage until I found it. No picture...cuz it's gross.

Found the passenger wheel well filled with dirt, behind the plastic guard! There's a write-up on the TDIclub forums about that...I'll link to it when I have a minute.

To get the passenger strut pushed in, we used a dowel and a small floor-jack - w…

The skunk.

Wrote this after an interesting morning. I was going to post up a picture of some of the carnage...but decided against it.


This Friday morn, please sit down and join me for a short story that will amuse:

As I left the house at my usual time today, and headed up Ritson Road for my journey to the north (away from the traffic of the city), I could have hardly realized what a tragedy the morning commute would be. The little black Jetta cruised lazily up the back roads, unexpectedly obeying the speed limits, and my thoughts were on the lovely surroundings.

Now, as commuters have been known to do, my attention wandered from the open road in front of me to things that tended to stand out. I entered a longer straightaway and saw a bump on the road, but could not make out what it was. At any rate, it was in the other lane, so my attention was more of a curious nature. As I drew closer, my nostrils betrayed what the decrepit bump on the road was, and my attention, now much more alert, was dra…

Performance Counters - Analysis

I've struggled to find a good source on how to properly interpret performance counters. In our case, it was determining IOPS for a potential SAN we were looking at. I had really been trying to convince the management that we could better utilize our current server-base if we set up a SAN and went ESX for production (we had ESX for testing already). They were not convinced that the SQL servers would fare well under ESX, so I started researching.

I spoke to a number of vendors (Xiotech, Lefthand, EMC, Equalogic), and all of them wanted to know how many IOPS I needed out of the solution. They then of course went on about how many their particular ware allowed, but I digress... I had no idea how to calculate IOPS (I/O per second) requirements, so it was off to the internet to figure things out. One of the vendors offered to decode perfmon logs for me, but I really wanted to know how to do that myself. Besides being a handy skillset to have, it meant much less time spent waiting…

Jetta dogbone mount

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After a weekend of replacing suspension bits (struts, mounts, bushings, etc), my last task was to remove the dogbone mount and replace it with a new one. I got four of the five bolts out, only to have the fifth snap off at the head. The bolt has completely corroded itself into the mount's bolt-hole, and no amount of Roost-off is helping get it out. Tried hammering, prying, etc, for an hour or so, but no luck.

H is going to bring over his torch - hopefully that'll work.

Update: I ended up jamming a cold chisel using a jack under the side that would move, then hammering some more on the stuck end, and prying up while hammering on the stuck end. Eventually it started to move and came off. The corrosion was fierce! I cleaned out the threaded holes with anti-rust stuff and brake cleaner, then blew them out with compressed air. I used anti-seize when putting it all back together, and torqued accordingly.

Sheesh!

The first two pictures are of the mount itself - the part that atta…

What to expect

Good afternoon!

I'll be posting up lots of things here, partially as a reminder for myself, and partially for those random Google searches...I know some tech blogs have for sure helped me, so I'll try to give a little back.

Expect content to range from IT tech issues to engineering, automotive, photography, art, etc etc etc.

Until then...


CT