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Hi there

 

I'm currently using a 256GB SSD as an SSD Cache on DSM6.1.

Turns out I can only use the disk as a cache for ONE volume. Seems like an awful waste.

Is there any way to tweak things so I can use a single disk as a cache for two volumes? Even better would be to use the remainder as an additional volume.

Possible?

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AFAIK it is not possible to use a SSD for more than one volume at the same time. It would be difficult to implement (concurrent accesses) and would slow down the cache performance.

 

The more data is read or written the more the SSD will be filled. So it can't be used as another volume. Maybe you should use separate SSDs with smaller capacity for each volume. 64GB cost around 30 €...

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Hey, aye thought so.. Thanks.

 

Even with concurrent access, it would still be better than a physical disk - so should provide some benefit.

The problem isn't with buying extra disks - it's SATA interfaces..

I have 6 SATA ports on a Mini-ITX board (all used), which has only one PCIE interface (used by dual port Intel NIC), so the only option might be to get a board with additional PCIE interfaces..

Oh well.. :sad:

 

Can anyone recommend a working (with Synology) PCIE SATA3 card please?

Preferably PCIE x4 but it depends on the number of ports.. :grin:

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Hey, aye thought so.. Thanks.

 

Even with concurrent access, it would still be better than a physical disk - so should provide some benefit.

The problem isn't with buying extra disks - it's SATA interfaces..

I have 6 SATA ports on a Mini-ITX board (all used), which has only one PCIE interface (used by dual port Intel NIC), so the only option might be to get a board with additional PCIE interfaces..

Oh well.. :sad:

 

Can anyone recommend a working (with Synology) PCIE SATA3 card please?

Preferably PCIE x4 but it depends on the number of ports.. :grin:

 

Buy a Dell Perc H310 card the flash it into an IT mode. Confirm it works on both DSM 5.2 as well as DSM 6.0.

Or https://www.newegg.com/Product/Product.aspx?Item=N82E16816124064 if you don't mind 4 ports only.

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I'll probably go for a consumer rather than server option tbh..

 

The second one's only PCIE 2.0 x1 - which means it shares 500MB/sec between the four ports (not great, especially for SSDs).. I'm looking PCIE 2.0 x4 minimum (2GB/sec)..

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Nope. Can't be done. Use smaller size SSDs for this purpose. The first reply is giving you what you should do.

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Hi there

 

I'm currently using a 256GB SSD as an SSD Cache on DSM6.1.

Turns out I can only use the disk as a cache for ONE volume. Seems like an awful waste.

Is there any way to tweak things so I can use a single disk as a cache for two volumes? Even better would be to use the remainder as an additional volume.

Possible?

If you do some system testing you will probably find that your current use of a cache ssd is also a waste. DSM Doesn't even use large amounts of memory the way you might expect, so there can be another waste. Test your system remove the ssd cache and test again.

I have found no value is a ssd cache and any memory greater than 8 Gb.

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Quick question about SSD Cache I'm planing to get one, if a power failure happens would i lose data?

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On 5/26/2017 at 9:22 AM, GaryM said:

If you do some system testing you will probably find that your current use of a cache ssd is also a waste. DSM Doesn't even use large amounts of memory the way you might expect, so there can be another waste. Test your system remove the ssd cache and test again.

I have found no value is a ssd cache and any memory greater than 8 Gb.

 

This is a bit of an old post and not sure I'll get a response but I'm curious about the cache a bit more.  I'll have exactly 8gig of RAM.  Would my system be ok without cache?

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On 10/19/2017 at 11:16 AM, setzer715 said:

 

This is a bit of an old post and not sure I'll get a response but I'm curious about the cache a bit more.  I'll have exactly 8gig of RAM.  Would my system be ok without cache?

You read my findings, have your test results been the same as mine?

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On 11/13/2017 at 11:34 AM, GaryM said:

You read my findings, have your test results been the same as mine?

 

This is my first NAS.  I had old equipment that was a dedicated Plex server but wanted to convert to a full NAS with Olex running on it.  I haven't seen any issues with performance.  I have it set up to sync to Dropbox (soon to switch to Backblaze) and an external drive to back up.  I transfer large files over gigabit Ethernet and average 112MBps.  Honestly I'm happy and do not plan to add an SSD for cache.

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