SSD

I actually prefer that the Supermicro does not have power lights for each slot. When disks are being acessed it is very obvious. Figuring out which slot is occupied is not a biggee for me.

Nice thread on where to shop for UPSes and replacement batteries: http://lime-technology.com/forum/index.php?topic=12548.0

Can you elaborate a bit on what make you feel this way? Why certainly good sir. ICY Dock issues where mostly around what I perceived to be cheap drive cages. To me, this did not justify the cost. Right now it is $25 more then the next two cheapest, the Norco and SM units. That along with what lookd like not the greatest airflow in the rear made me less than thrilled. Once I plugged in my Corsair Molex cables and then tried to plug in SATA cables, quickly realized that wouldn't work. Many of the modular Molex cables come with those tabs on them (here) and those won't work. Icy Dock layout places some of the SATA plugs right below the power plug. No other cage had this design. So have to go find a splitter... Don't get me started about the fan either. iStarUSA - cheapest of the bunch, does have that going for it. But on the model I have at least, zero airflow openings in the front. Be really concerned with heat. I cannot test right now as I have already had to RMA the unit due to tray5 not working. I was turned off on the design of the locking mechanism for the drive cages. It seemed like the slightest pressure on them would pop it open, forcing me to use the itty bitty locking mechanism. Which is probably there because they know they pop open so easily. Unlike the Norco and SM, another custom fan connector on this one as well. After working with all four, I can say these two are in the bottom of the pack. But, this is my opinion. I really liked working with the Norco and SM models. Now, at $95 you cannot beat the price for the iStarUSA unit and both it and the Icy Dock will more than meet most people needs. But, personal preferences and all, I would go for the other two. Shawn Very helpful! Will be interesting to see your temperature benchmarks and see which ones do the best job keeping drives cool. Thanks Shawn!

Monoprice.com Monoprice is a great place for cables (SATA, network, audio, video, and more), splitters, adapters, and a few PCI / PCIe controller cards. They do not carry the SAS breakout cables, but there was a recent post that they might be adding them. This vendor has an excellent reputation for quality products at low cost.

Can you elaborate a bit on what make you feel this way?

After using both, for my purposes I like the SuperMicro better. The larger fan and the aluminum trays trays are all positives for me. (I have about 50% 7200 RPM drives.) I do not think that the Norco tray bottom would act as a heatsink. A heatsink requires direct physical contact to work very well, a good heat conductor (copper or aluminum most commonly), and a shape to help disapate the heat. I think the bottom would have the opposite affect, it would trap hot air between the bottom and the drives and interfere with ventilation. I think I would dremel them out if I had one. I also wanted to comment on the plastic handle. I agree it feels a little flimsy, but I have never heard of anyone breaking one. It does make you treat is a little gently, which might be a good thing, so that you are less apt to try and force the thing closed when it isn't in quite right.

I believe the Norco trays are steel.

This is awesome! Thank you so much for taking the time to do this review. A few comments, based on some experience with these cages: 1 – The SuperMicro is the only cage with a 92mm fan. Other all have 80mm. This has an impact on the cooling potential of the cage. So long as the drive temps are controlled, the fan size doesn’t matter. But different seasons might require more or less cooling. 2 – The hottest part of the drive is the bottom. Having the “cage” more open on the bottom allows more airflow. Both the SuperMicro and the Icy Dock are completely open on the bottom. The iStar is more ventilated than the Norco. (I could see a dremeling opportunity with the Norco cage bottoms). 3 – Although the SuperMicro is the deepest of the bunch and has caused problems for some cases, the Norco unit may create challenges for some. The SuperMicro clipon fan is not as tall or wide as the main unit, this leaves room for cable connections and for motherboard overhang. When considering your case and cage preference, keep the depth as well as height and width towards the back of the unit, in mind. 4 – I have had both the Norco and SuperMicro. Both are well made. The nice thing about the Norco is that it does not have these removable plastic inserts (the size of a hard disk) that must be reinserted (with the annoying screws) should a disk be removed. (Presumably the plastic insert maintains similar airflow characteristics with the plastic insert in place). But the SuperMicro has the completely open top and bottom. Looks like the IcyDock have just a bar that must be removed / replaced with a disk is inserted / removed. Similar concept. Although the SM plastic trays are a pain, they do make good spare part bins . 5 – Interesting that the Norco is the only unit that has individual air channels for each drive. This means less room for airflow between the drives, but also, in combination with the air shutoff feature on each cage, allows you to block airflow through certain channels. The jury is still out, IMO, whether the individual channels are a positive or negative. I am really interested in the following test. Load all 5 slots with disks (5 x 5400RPM). Disconnect all other cages (so they don’t impact the test). Close up the case, and run preclears (with –n option to immediately begin writing which should generate the most heat) on them for a certain period of time (say 1 hour). Check all of the drive temps. Do it in each of the cages (same disks in same order), running just drives in that cage. Then repeat in the next cage. Repeat with 7200RPM disks. You could run this with a dd command from disk to /dev/null (if you do this use a larger buffer). I don’t think drives get quite as hot when reading, but results would likely be similar if actual writing to the disk is not desired. Report ambient when you report your findings, in addition to your case cooling. A slightly warm ambient might be most useful to give a sense of how hot the drives would get under summertime conditions (ambient about 78F).

Buy.com Buy.com is a great place to shop for the SuperMicro CSE-M35T-1 5-in-3 "hotswap" disk cages. At ~$96 with free shipping, I have not found better. There is an easy to find $5 off first order over $100. Also, budget (free) shipping is amazing. I placed an order on Friday and it arrived by 10AM the next day (Saturday morning). Last time I ordered from them the order also arrived next day (but it wasn't a weekend), and I thought it was a fluke. Shipping for this item was from PA, which is about a 5 hour drive from where I live. After 4 perfect transactions from buy.com, I would recommend them.

We all know that Newegg and Amazon are good sources for unRAID parts and drives. But there are other merchants that are also well-priced and worth considering. And there are certain places that are the best for buying specific things. The purpose of this thread is to allow users to provide specific recommendations on where to (or not to) shop for what.

12 at a time might be a record! Are the speeds > 100 MB/sec? Will be interested in total wallclock time to complete. How much RAM is in your machine?

Any theories of why this would happen? I'm wondering if these were aligned in time. Might be nice if preclear logged the date/time of a preclear post verification read error. And even do some retries to see if it is really a data issue, or a memory or other system issue.

I got some strange results running preclear (v 1.6, unRAID version 5.0b4). I was running three preclears at once in screen - 2 3T and 1 2T drive. Each of them got a single error on the verification step. Here are the results of each of the postread_errors files. skip=236000 count=200 bs=8225280 returned instead of 00000 (3T) skip=260800 count=200 bs=8225280 returned instead of 00000 (3T) skip=184400 count=200 bs=8225280 returned instead of 00000 (2T) This is the first time I have run a preclear on this (new) server. It is running a C2SEE-O motherboard (2 3T drives on this controller), and a BR10i controller (2T drive is on this controller). After a reboot I tried to double check that the values of these blocks was truly zero. Here are the results: root@Shark:/boot/unmenu# dd if=/dev/sda skip=236000 count=200 bs=8225280 conv=noerror 2>/dev/null|sum| awk '{print $1}' 00000 root@Shark:/boot/unmenu# dd if=/dev/sdb skip=260800 count=200 bs=8225280 conv=noerror 2>/dev/null|sum| awk '{print $1}' 00000 root@Shark:/boot/unmenu# dd if=/dev/sdd skip=184400 count=200 bs=8225280 conv=noerror 2>/dev/null|sum| awk '{print $1}' 00000 Whatever the problem, it is not memory. I ran the memory (4G) through a 2 night memtst - no errors. Have you ever seen this before? Any ideas what might have caused it?

How many read-only parity checks did you run and get the same results? Based on my read of the thread, I think you got 12 the first time, then again and got 11, and then a third time and got 11. Is that right?

What disk drives are you running. 2T Samsungs have a bug called "silent corruption" that may be able to cause the symptoms you are seeing. What motherboard are you running. Some motherboards don't work well. That doesn't always mean they won't run at all, but can mean that they don't run reliably. Your may have one of those. Suggest you post full system specs and a full syslog.

Glad to help. Hope you are able to solve your issue!

You can run smart reports on each drive and look for errors there. You can also double check your cabling to your drives. Read on, however. I suspect your issues are not drive or cable related. unRAID calculates parity by adding the corresponding bits of your data disks. If the result is odd, parity is set to one. If the result is even, parity is set to zero. In this way, the corresponding bits added together across all the disks is always even. So if unRAID finds that the sum is odd during a parity check, you have a sync error. Very simple. When unRAID finds this, it has no idea which disk changed, but what it will do is update parity to make the bits add up to to be even again. Some people call this correcting the parity error - but "correct" may not be the best term. If is a very syntactic "correction". Now lets say your array is perfect, parity is perfect, and you run a parity check. The parity check will have zero sync errors. But let's throw is a bad memory chip - say one that results in a flipped bit 1 in a trillion times. So your parity check is running along perfectly, and the memory error occurs in the memory buffer of disk contents. unRAID trusts that the memory contains an exact copy of the data from the disk. So unRAID will see a parity mismatch and update parity to be consistant with the bad read. With this happening 1 in a trillion times, and you have 10 2T drives, you might expect to see 40 or so sync errors. Now, after the parity check, parity is NOT perfect. On 40 places on the disk, parity has been mistakenly updated because of the memory error. Now let's say you buy new memory, run it through a weeklong memtst and KNOW the memory is perfect. You now run a parity check. What will be the result? 40 sync errors. What it did was to CORRECT the 40 mistakes it made the last time. But what if you didn't replace the bad memory and ran it again. The chances of the memory error affecting EXACTLY the same disk locations are staggeringly low. So what will happen in in about 40 new spots memory will get corrected, and unRAID will adjust parity (incorrectly), but in the spots that were memory corrupted on the last parity check, unRAID will correct parity. Net result, ~80 sync errors. You are still left with ~40 bad parity situations on your disk. It is possible that your system memory is fine and the one of the disks or disk controllers or chipset is corrupting the information before it gets to your computer's memory. Drives have protections to prevent this, but it is still possible. But it is far easier to rule out the memory first. It is fairly common - especially if you are running 2 sticks. One thing you can look at are the parity mismatch locations in your syslog. If you are seeing the same sector marked bad and then marked good on the next parity check, if usually means you have a memory error. And remember, when you finally fix the problem, you will still have one more parity check with sync errors that will truly correct parity. After that, sync errors should be zero. Many users that find a bad memory chip are frustrated to find that it didn't fix the problem because the next parity check results in sync errors. They don't realize that this really did correct parity and the next parity check will be perfect. Hope this helps. Good luck!

My guess is you have a bad memory stick. Run memtst.

I believe the drive is supposed to do pre-emptive reallocations when it has trouble reading data but is ultimately successful. Without such a feature, a parity check would almost never result in a reallocated sector. Am I missing something?

Good to go. Add it to your array and enjoy your new drive!

what about me? Sorry - I use my iPhone and read forum in text mode first thing in the morning. Can't see embedded images. But I just took a look. Something is not right obviously. Suggest you wait for Joe L. who wrote the preclear script. He can probably explain what could cause this.

Cherritaker - your disks look good! No sign of reallocated sectors. Add them to your array and enjoy!

redia - Looks good. Of course, this is only showing the difference between the smart report before doing the preclear, and the smart report after doing the preclear. If the disk had a serous problem before you started and didn't get worse in the preclear, this would not show it.

The reallocated sector count at 216 is a definite problem. It is encouraging that you were able to preclear the disk without the count increasing! Otherwise the difference would have been highlighted by the preclear output. But I have never seen a drive with more than 1 or 2 reallocated sectors that didn't continue to degrade with each parity check (although I've read reports of people with over 100 that have held steady). If this disk were in the array, I would suggest that you run a parity verify (read only parity check) and see if the 216 number holds steady. If it did, I would suggest running another one. If you could run 3 in a row and not have the number increase, maybe the drive is okay. But since you are in the preclear stage, you might want to run it through 3 preclear cycles. If the number holds steady, I'd consider trusting the disk. But it would be a world's record of most reallocated sectors on a stable disk from all the smart output I've seen! The other attribute to monitor closely is the current_pending_sector. This is the number of sectors that have been flagged to be reallocated. You did not post this value. The "raw read error rate" is nothing to be overly concerned about unless and until you start to get close to the threshold for failure. And you are no where close. This is a good example of where the diff list of pre-preclear smart output and post-preclear smart output is not sufficient to identify all problems.

Welcome to the unRAID Forums! Most of the documentation for unRAID is available via the Wiki. Below are links to some of the highlights to help new users get started. Getting Started with unRAID A guide for new users of unRAID FAQ Frequently Asked Questions Un-Official unRAID Manual A copy of the unRAID user-manual edited by owners of unRAID to be more accurate, up to date, and complete than the official version. Best of the Forums Some of the best forum threads identified by unRAID users Troubleshooting When requesting assistance from unRAID community members a description of the symptoms of your issue is a good start, but frequently not sufficient to diagnose the cause. The information needed to perform an analysis is mostly contained in the system log and/or smart reports. The troubleshooting section of the wiki describes how to capture these files, which can then be zipped and attached to requests for assistance. unMenu and myMain Add ons developed by community members unRAID WIKI The unRAID wiki, has two sections. The "Official" section edited by lime-technology, the "Un-Official" section edited by users of unRAID. Recommended Builds Common builds using hardware known to be compatible with unRAID, a good starting place if you are interested in building your own unRAID server. unRAID Roadmap Lists the planned new features and enhancements by version. Also shows progress by feature in the next build. Check back often. unRAID Configuration Guide Step by step instructions to configure a new array with some popular unRAID addons. Welcome aboard! Here are links to some old stickies that may still be of interest to some users: EARS Jumpered / Unjumpered Thread Release Information ACPI Questions? Will server Power button gracefully shut down the server? To Cache drive or not to Cache drive? How-To: Migrate from unRAID 4.7 to unRAID 5.0 Remove Drive Without Losing Parity - The unRAID Moderators