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aprib

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  1. Thank you for the response. Is there a more detailed article I can read somewhere that explains the finer and more advanced settings of DP, for example what each balancer does, case scenarios explaining why and when you might want to disable/enable a balancer. Since you have given us the option to enable or disable a particular balancer, I am assuming there are scenarios where you envision it should be disabled, and I'm curious what they might be and why. ---- When you say this, "As for balancing/duplication, if you have real time duplication enabled (default), then the files are written to both disks in parallel. And this should respect the balancing options." .... am I understanding things correctly that when I create a pool from 2 empty drives (with file duplication where everything is duplicated without exception), with real time duplication enabled, every input to the pool will always be balanced/duplicated to both disks at any and every point in time, so I don't really have to enable balancing at all.
  2. I scheduled the balancer to run while the VM was off and there was no error. So it seems that the balancer leads to the error in a pool with a running VM. ----- I tried starting the VM while the balancer was running and got this message. I'm not sure what the balancer does behind the scenes but it took the balancer about 15 mins to complete a run on a pool with 50gb of data. ------ Update 1: It looks like the balancer modules are running one by one in series. Around about 20 minutes into the balancer scheduled start, I can start the VM. Now at minute 35, again the VM file is locked. Update 2: Minute 40 VM starts, at minute 50 it locks again. Update 3: Minute 90 after balancer starts, VM still intermittently locks. Does it take the balancer this long to do whatever it does in a 50GB partition. ----- I am starting to feel that DP is not suited for use by a 24/7 Virtual Machine. I can easily schedule a VM to stop prior to balancing but when do I schedule the VM to start again? As the contents of the pool grows bigger I assume the time it takes the balancer to run will also increase. Now I'm curious how storage spaces' balancing algorithm handle their workload, you're both using the same 'kernel' (if that's the right word), there can't be too many different ways of going about it.
  3. My setup is a notebook with 2 drives, with 2 partitions in a DP file-replication pool, windows 8.1 with Hyper-V. I remember reading in another post somewhere that for always-on VMs, DP's balancing algorithm will choke up (or something will happen), if we don't turn off the VM prior to the running of the balancer. And I think that's exactly what happened this morning at 6am when the balancer was scheduled to run on a pool with a running VM. I have not tested turning the VM off to see if the error shows up at balancing, I will try this next. What do you suggest I do for 24/7 VM's. Does anyone has a best practices tips for running virtual machines in a DP pool. ps. I think you've got something special here and I've purchased DP anyway even though I'm only 1 day in my trial. Keep up the good work.
  4. If you're curious about SSD lifetimes, I wrote this in an older post on another forum. -------- For those wondering on lifetimes. Assuming 1000 write cycles, I am now on my 7th cycle (Item AD on crystal disk info. Each SSD manufacturer implements this differently, it may not be item AD on yours). Crystal disk info reports 4554 power-on hours. At 15 hours a day, translates to 300 days of usage (and in fact correlates to the purchase date in Sept 2012). So if 300 days is 7 cycles, then 1000 cycles is 42857 days or 117 years. I am not a video or graphics professional and my games are on a HDD, so my SSD usage is mostly office work. Your mileage may vary. In fact the rated write cycle of a regular mlc ssd is 3000 cycles, so with my pattern of usage, the ssd will last 350 years. ----- Here is another interesting read: They tested to the death a samsung TLC rated at 1000 write cycles. In summary they died at around 3000 write cycles, 3x what samsung claims. http://us.hardware.info/reviews/4178/hardwareinfo-tests-lifespan-of-samsung-ssd-840-250gb-tlc-ssd-updated-with-final-conclusion
  5. For those of you interested, here is the performance of the drivepool drives. The read speed is similar to a single SSD drive (however does not seem to stripe the data and thus increase read speed) but the write speed is half that of a single SSD drive. --- Remember that one SSD is in a SATA3 port and the other is in a SATA2 port. In reading, the pool reads from the SSD in the SATA3 port but what is curious is the hit in the writing speed. I expected the write speed to be close to the speed of the SSD in the SATA2 port but it's significantly lower.
  6. Thanks Alex for the enlightening answer. I am now in the process of my trial. Unfortunately my skillset does not yet cover iSCSI and related technologies, although the synology is here now. So until I get there, currently I have my HyperV VMs running in a file-duplicated pool of 2 SSD partitions (of 2 SSD Drives). My next question is going to cover best practices for running a 24/7 HyperV VM in a drivepool drive. If I can't find what I'm looking for from past posts then I'm going to create a thread. ------- The reason I ask about different speed is that I am on a laptop where one of the SSD is sitting in my CD Drive with a caddy. And although the SSD is the same type, being in the caddy, the speed is about 30-40% less, probably due to the SATA port of the CD being SATA2 instead of SATA3. The first image is SSD in HDD Port and second is the same type of SSD in a caddy in the CD-ROM slot of the laptop.
  7. Thanks for all the responses. Follow up question regarding diff speed drives: Say I have 2 drives in the pool, one is HDD one is SSD. And I setup folder duplication from the SSD to the HDD. During heavy and continuous operation to the SSD source folder, eventually the HDD will lag behind the SSD. If this discrepancy gets big enough, what happens then? (I assume this is not recommended)
  8. Thanks for that. I usually run a RAID 1 for my VMs but I was wondering if I can duplicate the VM folder to the NAS and free up one local disk.
  9. Hello all. I have not yet had a chance to download drivepool, since I am waiting for my synology NAS to come, but first I have a question. I am thinking of doing a duplicated folder setup. The source folder in my PC contains a VMWare VM on an SSD drive. The target folder for duplication will be on the synology NAS with a HDD. Obviously there will be a huge speed difference between the write speed of the source and target. How will drivepool handle this huge discrepancy in write speed, is this even possible to do or inadvisable. ---- During heavy VM operations eventually there will be a big and continually growing discrepancy between the data written to the SSD and the NAS HDD. At some point I would guess DP will crash. Or will DP limit the write speed of the SSD to match that of the target NAS HDD speed.
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