Hi,
I want to increase the performance of my zpool. One way of doing this, is adding an SSD for ZIL and/or L2ARC. However, I wonder if this will be effective. And if it is, how much effect will it have?
To figure this out, getting a good idea of the ARC and ZIL usage would be very nice. But how does this work with FreeBSD? Most ZFS tutorials assume Solaris is used. And those commands often don't work with FreeBSD.
The whole ZIL business is a bit confusing. Some say a ZIL needs to be mirrored. But according to this guy, mirroring a ZIL isn't really needed anymore. But, what happens if the SSD dies? Does the zpool continue to operate normally? Will ZFS fallback to ZIL in the zpool itself? Do I need to replace the SSD immediately? Or can I take my time to order a new one and replace it at whatever time fits me best, taking the lower performance I have in the meantime for granted? That isn't very clear from the answer. And how do I check if my zpool meets the needs (ZFS v19) for a non-mirrored ZIL?
I have only one spare tray and SAS connector, where I can place 1 SSD. I was thinking to divide it into 2 partitions and use 1 partition as ZIL and the other as L2ARC. The SSD I have in mind is a Samsung Pro 850. That is a SATA SSD, not SAS. Is this ok? Or is it a horrible idea? Does someone have experience with this, or a similar, setup?
I really want to be well informed, before getting down this road. Any tips, suggestions, explanations or pointing to good reading material would be most welcome.
Thanks in advance
I want to increase the performance of my zpool. One way of doing this, is adding an SSD for ZIL and/or L2ARC. However, I wonder if this will be effective. And if it is, how much effect will it have?
To figure this out, getting a good idea of the ARC and ZIL usage would be very nice. But how does this work with FreeBSD? Most ZFS tutorials assume Solaris is used. And those commands often don't work with FreeBSD.
The whole ZIL business is a bit confusing. Some say a ZIL needs to be mirrored. But according to this guy, mirroring a ZIL isn't really needed anymore. But, what happens if the SSD dies? Does the zpool continue to operate normally? Will ZFS fallback to ZIL in the zpool itself? Do I need to replace the SSD immediately? Or can I take my time to order a new one and replace it at whatever time fits me best, taking the lower performance I have in the meantime for granted? That isn't very clear from the answer. And how do I check if my zpool meets the needs (ZFS v19) for a non-mirrored ZIL?
I have only one spare tray and SAS connector, where I can place 1 SSD. I was thinking to divide it into 2 partitions and use 1 partition as ZIL and the other as L2ARC. The SSD I have in mind is a Samsung Pro 850. That is a SATA SSD, not SAS. Is this ok? Or is it a horrible idea? Does someone have experience with this, or a similar, setup?
I really want to be well informed, before getting down this road. Any tips, suggestions, explanations or pointing to good reading material would be most welcome.
Thanks in advance