Acuum

Thanks Rob.

Joe - As always thankyou very much! just to check, the spin down time on the *cache* disk, is this written to the firmware of the hdd? I wondering if it will survive a reboot or if i need to add that line to my go script?

Hi guys, As part of my install and to make following these instrcutions easier i decided to add a disk outside of my array to store my packages and have unraid on. I called this disk cache so MusicMans instrcutions worked for me. this is not an unRAID cache disk - i only have the plus licence. Is there a way firstly i can mount this disk as an SMB share like this \\tower\cache And secondly can i set the spin down timer on this *cache* disk? it seems unraid only spins down my array disks. thanks.

Thanks Joe.

that all makes sense - And im sure that you've read that infomation somwhere and so it is factual. But it has raised questions in my head i probably need to go away and answer: I'm right in thinking though that even with a 15 disk array (14 data, 1 parity) to write to any single data disk you don't need to spin up all 15 disks, just the parity disk and the disk being written to? the rest can be worked out from knowing what the bit was before you changed it, and whether you have changed it? the 4 IO steps you meantion this I'm still unclear on. My guess is that you're saying they are read data bit, read parity bit, write data bit, write parity bit. Surly if a compare is done on the data disk before a bit is written to it. then there is no need to read from the parity disk? for every single disk write? if you take for granted at at time = 0 seconds i.e. array has been built and parity has been calculated there are no mistakes. then any time I write to a data to any data disk all i need to know is: is the bit im about to write = to what is already there. if it is then parity bit is left alone. if it is not the same then flip the parity bit. why do i need to read the parity bit unless i have to flip it? (I understand that when a flip opperation is to take place then i have to know what it started out at in order to work out how to flip it) What huge stupid mistake have i made in my assumption there? On a slightly more on topic note: I've also seen since my post earlier that it's going to require more than just the parity disk and the data disk contating the section of the Virtual disk in order to write to a virtual disk. I'd over looked the NTFS table being at the begginging of the first (virtual) disk in my spanned volume... I might look to move it arround so that that specific data is sitting on a newer disk as it's going to be spun up every time i write anything to my big virtual disk... anyway we'll see. I've still got a lot of data to move and a huge ammount of sort of said data to do.

One last thing to note ... the OS drive is not on an unRAID drive. that's sitting on a disk that is outside of my array and is used for isntalling vmserver to and hosting OS Virtual disks. the Virtual disks are only used for storing media files and are basicly designed for WORM archiving my data. Raid 5 would work as somone sugested but i need unRAIDs biggest selling feature - the ability to have RAID5 protection with JBOD expandability. this is exactly what i've gotten now and i can work in Windows for my file shares which i feel confortable with. (my 9 to 5 is a windows admin...)

GOOD NEWS! - it was a busy weekend testing stuff here's what I found. (I did consider cache disk - but it wont work as you can’t move data from a cache disk into a virtual file structure on an unRAID partition) I have run some more test and importantly it was worth noting that I wasn't complaining about the speed of my unraid protected disks when it was partiy protected, but the virtual machine inside of them. more accuratly the DRASTIC difference in speed between the two. Writing to the unraid disk when parity was protecting it, was still producing much faster disk writes than the VM inside of it. (more on that latter) @ praeses Spanning my Virtual disk across multiple unraid disks would not lead to as much read write work as you stated - (from my understanding.) a MS spanned volume does not write (or read) to each spindle on every write. it basically starts at the first volume and fills it up, then starts on the second volume etc etc. Now provided Tom's implement this the way I (assume and ) hope he has - there should be no reason to read from any of the other disks in order to write a parity bit. - you it can be calculated based on the bit your currently writing to a data disk. if bit being writtin is 1 and parity is 0 then change parity to 1 if bit being written is 0 and parity is 0 then leave parity alone if bit being writting is 0 and parity is 1 then leave parity alone if bit being writtine is 1 and parity is 1 then change parity to 0. ( i might have that table out of whack.. but it's all the same. - provided you know hoe many disks are in the array then you can calculate whether you need to change the parity bit on each write through only reading/writing to the parity disk and reading/writing to the current data disk) So... here's what I did to improve the performance of my Virtual machines disk writing performance. step 1) turned off virtual memory - no point in using very slow virtual memory when I’ve got a 4GB server allocating 2GB to the guest OS. step 2) took the parity disk off my array to double check performance. - it still sucked "£$" step 3) changed the Virtual machine policy "Write caching - to - optimized for performance" This resulted in 25 MB/s write speed instantly. this speed also doesn't drop off even with a 40+ GB transfer. So I'm very happy. it's all working well. I can also confirm that if I let all unraid disks spin down and I start writing to the Shared disk that is made up of 3 virtual disks 230 GB each split into 2GB pre allocated files spread across 3 unraid disks only the a single unraid disk spins up. (this is the unraid disk that has the relevant section of the virtual machines file on it. As I’ve only put 100GB of data into the Virtual machines hdd it's currently only spinning up the first unraid disk. I have yet to add the parity disk to the setup so this is far from proven - but as all the media I want to store is currently sitting on the soon to be parity disk I can't really check. besides it's quicker to copy the 1TB of media across and then put parity on than to calculated it at the beginning and then pay the performance hit for every additional MB I add latter. (Basicly it was step 3 that made the difference. )

MusicMan - Thanks for all your help after a very long saturday i eventualy got it working. ;D My tests so far have been to install a Windows 2k3 server on a non array based disk. and then create two virtual volumes one on D1 of the Array and one on D2 of the array. I then created a Dynamic disk to join these two into one volume from within the my virtual 2k3 box. I've then made a share on the *protected* volume and my plan is to share my media from this. This all worked as expected how ever.... transfer rates are dismal... It starts off with about 20MB/s write to the share but this drops off at a pretty steam 0.2MB/s untill it gets down to a write speed of 1.5MB/s where it stays... Transfering data directly to one of the unraid protected disks it also starts off at about 20MB/s but that then drops down to arround 15MB/s. I've read some reports of poor disk IO performance in Virtual Server 2 but 1/10th real disk speed is far worse than i was expecting. has anyone had any experiance with this? I am using old-ish 250 GB disks, one of which could possibly be on it's last legs... but even so 1/10 the speed of a transfer directly to the protected disk would indicate to me that Virtual Server is to blame for this problem... any thoguhts?

IT WORKED! THANKS MUSICMAN!

cool back to trying this in my VM which ran a WHOLE lot faster than my physical box. i'll no doubt be back latter where it work or not

MenuMan. I had been using yoru config file. I was deleteing the .config from that dir, then opening the same file name in nano and pasting your config file into a the (now empty) new .config file and saving it. however i hadn't realised that doing this meant that the "make menuconfig" command could then be skipped if i had done this. So to double check: step 1) done previously step 2) can skip for DVD isntall of 12.2 Slackware and 4.4.2 unraid step 2) done previously step 4) can skip for DVD isntall of 12.2 Slackware and 4.4.2 unraid step 5) do everything step listed in post step 6) cd /usr/src/linux make clean paste .config file using puty <skip>make menuconfig</skip> step 7) complete all steps listed in post step already done step 9) cross fingers... Thanks MusicMan.

unraid 4.4.2 http://download.lime-technology.com/unRAID%20Server%204.4.2.zip

Hi, two days and one everning in and i've yet to get it working. Can somone point me in the right direction? I have followed the steps (using 12.2 and skipping steps 2 and 4) and thigns seems to be build but it then doesn't boot. I guess i've make a mistake in the menuconfig section. it loads a gui with a WHOLE load of options in it. is there a sure fire way of knowing what to change? I've tried this in both a VM, and on real hardware with the same results. any help could be great. thanks A

General Noobie-ness and an inability to pieve together three sets of instrcutions for different versions of slackware and or unraid. I'm getting there and havn't totatly given up. (all thoguht last night at 11PM when i stopped my VM booting was a low point...) I'll remeber not to mess with both the kerneles i've got the lilo pointing at in future and i really should create an undo disk... (Thanks for the offer of support - this forum has been nothing bu helpfull, but i'll post my help requsts on the thread i with the instructions so as not to drive this thread of topic.)

nice work JM. Wish I'd had your success this weekend! Two days down and i've yet to get a booting unraid develepment enviroment working despite following the extensive threads and how to guides (in different place) by the like so MusicMan. I might just put it off untill 4.5 comes out of beta so i don't have to remake the development enviroment when the new versino come about. (Very frustratting weekend!) It really is a shame that this functionalilty can't be automated from start to finish. As great as the threads are they don't seem to be noob proof.