We have a re-purposed Dell R610 which unfortunately, only has 32GB of RAM. It has 2 x LSI SAS 6Gbps cards, connected to 2 x Dell MD1220 arrays. The arrays hold a mix of SSD and SATA drives. I have 2 x 10Gbps ports into this server, 2 x 1Gbps for management.
I have a zpool stripe which consists of 4 zdevs that are 4 x 1TB WD Red drives in a RAIDZ1.
This device is an iSCSI VMware target, used for SQL backups. So we're sending single files once a night of 500GB+, then every 15 minutes smaller files, of a few hundred MB to a few GB. The nightly 500GB+ backups is read by another server to refresh its data. The full 500GB from the latest file is read every night.
I am only seeing a 17% ARC hit rate and I'm seeing a 0.0 hit rate for everything else like demand_data and demand_metadata.
I have recently been gifted 4 x 1TB SSD drives that I would like to utilize in some manner to improve backup and restore speeds for the 500GB+ nightly backups.
First - is this even possible? I could probably enable synchronous iSCSI for writes and set an SSD as an SLOG, but I can max out a 10Gbps link currently so I don't see the benefit there. I think the biggest benefit would be to cache the latest backup to an SSD via L2ARC somehow, but again, I don't think this is possible with FreeNAS.
Any suggestions - I'm open to experimentation also, as we back this data up elsewhere, so failure of this FreeNAS box is acceptable.
I have a zpool stripe which consists of 4 zdevs that are 4 x 1TB WD Red drives in a RAIDZ1.
This device is an iSCSI VMware target, used for SQL backups. So we're sending single files once a night of 500GB+, then every 15 minutes smaller files, of a few hundred MB to a few GB. The nightly 500GB+ backups is read by another server to refresh its data. The full 500GB from the latest file is read every night.
I am only seeing a 17% ARC hit rate and I'm seeing a 0.0 hit rate for everything else like demand_data and demand_metadata.
I have recently been gifted 4 x 1TB SSD drives that I would like to utilize in some manner to improve backup and restore speeds for the 500GB+ nightly backups.
First - is this even possible? I could probably enable synchronous iSCSI for writes and set an SSD as an SLOG, but I can max out a 10Gbps link currently so I don't see the benefit there. I think the biggest benefit would be to cache the latest backup to an SSD via L2ARC somehow, but again, I don't think this is possible with FreeNAS.
Any suggestions - I'm open to experimentation also, as we back this data up elsewhere, so failure of this FreeNAS box is acceptable.
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