January 13, 201610 yr Nice, what cases are they? Have you got two or three arrays or are they linked somehow like some sort of SATA Medusa? I think you should be posting in unRAID Compulsive Design
January 14, 201610 yr I think it looks pretty cool!! Can you post this build and how you have it setup? I'm assuming given you seem to have all 3 working together on one parity sync you have these 3 8 bay enclosures linked to another box running unRAID? OR somehow have unRAID running on one of those babies (which I didn't know you could do) and have the other 2 linked to that box? I'd be particularly interested if they are linked to a single box or 2 into the other 1 what interface(s) you use (esata, usb3 etc) and (assuming all enclosures are full) what your Parity Sync speeds are?
January 14, 201610 yr Nice, what cases are they? Have you got two or three arrays or are they linked somehow like some sort of SATA Medusa? I think you should be posting in unRAID Compulsive Design Beat me to it!
January 14, 201610 yr Author Nice, what cases are they? Have you got two or three arrays or are they linked somehow like some sort of SATA Medusa? I think you should be posting in unRAID Compulsive Design Beat me to it! I'll do a detailed post over there shortly! But yeah, the wooden box to the left is the pc, the 3 8 bay boxes are to the side. I managed to fit all my drives into only two, the third is no longer needed, so right now it's a race to see what happens first- do I need storage first or will a drive fail. It's all being done on eSATA, 16MB/s sync. 44.5 TB array.
January 14, 201610 yr Nice, what cases are they? Have you got two or three arrays or are they linked somehow like some sort of SATA Medusa? I think you should be posting in unRAID Compulsive Design Beat me to it! I'll do a detailed post over there shortly! But yeah, the wooden box to the left is the pc, the 3 8 bay boxes are to the side. I managed to fit all my drives into only two, the third is no longer needed, so right now it's a race to see what happens first- do I need storage first or will a drive fail. It's all being done on eSATA, 16MB/s sync. 44.5 TB array. 16MB/s is your parity sync speed? That's not too great... I'm running one as we speak at 138MB/s
January 14, 201610 yr Author Oh really? Shoot. More likely the setup of 8 drives over esata or the fact that some of these are really old? I'd hate to have to recase this...it looks so cool!
January 14, 201610 yr Nice, what cases are they? Have you got two or three arrays or are they linked somehow like some sort of SATA Medusa? I think you should be posting in unRAID Compulsive Design Beat me to it! I'll do a detailed post over there shortly! But yeah, the wooden box to the left is the pc, the 3 8 bay boxes are to the side. I managed to fit all my drives into only two, the third is no longer needed, so right now it's a race to see what happens first- do I need storage first or will a drive fail. It's all being done on eSATA, 16MB/s sync. 44.5 TB array. I'd be interested to see that post when you do it. That reminds me, I have to finish my build thread too! Back to you though, it looks like a very sexy setup BUT given those Parity Speeds I am not sure how practical it is for such a large storage amount. However, if you are happy with those operations taking a while then that's cool. FWIW I am not too sure Id like the idea of waiting so long for a disk rebuild (should one fail) due to the chance of a second drive failing in that time. For that reason alone I hope you have a backup! I find myself pondering whether there would be a way to fix that eSATA bottleneck between the PC and the 2 (and maybe eventually 3 boxes) and give you better performance!?
January 14, 201610 yr Author What about 1m forward breakout cables attached to the PCIe card? I just googled these- interesting! Do they require a specific port on a motherboard? The boxes I have only have an esata/usb3 port on the back unfortunately. In the meantime, after trying to remove a few drives that may be bad, the parity sync speed dropped to 3MB/s!
January 14, 201610 yr What about 1m forward breakout cables attached to the PCIe card? I just googled these- interesting! Do they require a specific port on a motherboard? The boxes I have only have an esata/usb3 port on the back unfortunately. In the meantime, after trying to remove a few drives that may be bad, the parity sync speed dropped to 3MB/s! Do you mean the boxes only have one esata port on the back and it is shared by all the drives in the box? That is definitely going to be a bottleneck. I seem to recall a recent post where someone else was using an enclosure that had ports for each drive. Here it is. No follow up on how well it worked but it seems like it should. Maybe a bit pricey though.
January 14, 201610 yr Author What about 1m forward breakout cables attached to the PCIe card? I just googled these- interesting! Do they require a specific port on a motherboard? The boxes I have only have an esata/usb3 port on the back unfortunately. In the meantime, after trying to remove a few drives that may be bad, the parity sync speed dropped to 3MB/s! Do you mean the boxes only have one esata port on the back and it is shared by all the drives in the box? That is definitely going to be a bottleneck. I seem to recall a recent post where someone else was using an enclosure that had ports for each drive. Here it is. No follow up on how well it worked but it seems like it should. Maybe a bit pricey though. Yeah this appears to be the issue. Its odd because I would have assumed that SATA 3 / 8 would not be appreciably bad, but it clearly is. May have to abandon ship on these boxes...Going to try to move 1 to a PCI card to see if that helps.
January 14, 201610 yr For parity build, parity check, and data rebuild, all the disks are used at the same time. For data reads, only the disk with the file being read is used. For data writes, the disk with the file and the parity disk are both used. If you put parity and cache on their own port then you may not notice the bottleneck except for those special operations I mentioned above.
January 14, 201610 yr Author For parity build, parity check, and data rebuild, all the disks are used at the same time. For data reads, only the disk with the file being read is used. For data writes, the disk with the file and the parity disk are both used. If you put parity and cache on their own port then you may not notice the bottleneck except for those special operations I mentioned above. So my parity rebuild speed would be comparable to to this parity sync?
January 14, 201610 yr All of those things I listed which use all drives at once would experience a similar bottleneck. There may be some differences between them due to the actual read/write operations being performed. Think of it this way. Each port can only be used for one thing at a time. If each drive has its own port, then all drives can go at the same time. If some drives have to share a port, then they can't go at the same time. 4 drives on the same port will take about 4 times as long.
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