Also don’t work for Joyent, but we have some hosts that only run Windows KVM zones;
> On 14 Apr 2017, at 15:34, John Barfield <[email protected]> wrote: > > Does joyent set “sync=disabled” on windows zvol’s? Seems unlikely - to make KVM zones performant, you either need to use fast storage for the zones pool, or have a couple of write-optimised SSDs as log devices. > · Does joyent use “dedup=on” on cloud nodes? Also unlikely - we don’t even use it on our backup servers because of the performance hit deduplication causes. You’d be better off using NTFS deduplication within your Windows storage zones, as this runs on a schedule so you can run it during expected quiet periods. > · Is there a list of “best practices” options to set on windows VM’s > to get the most performance? Taking into account that the ZVOL will have ntfs > on top of it? As previously mentioned, using VirtIO devices where possible, and giving Windows enough memory to prevent Windows using the pagefile too much - especially if you don’t have fast storage or log devices attached to your zones pool. > · Is there a performance hit using thin-provisioned ZVOL’s? This shouldn’t make any difference - “thick provisioning” via refreservation is really an accounting feature. ZFS will only write to the pool when there’s something to write. It’s not like thick provisioning on a SAN where the entire LUN is zero-filled before use. I’d recommend you have the refreservation for each volume set to the same size as each guest volume; this will prevent you filling your pool by accident. > · Is LZ4 compression okay on a ZVOL dataset? Is there a performance > impact to the VM’s or the GZ? We use it on every pool - it actually increases disk throughput in most cases without any negative impact; the longest delay is still going to be seek/read/write time from the pool, not decompressing/compressing the data. > · Are there any performance options that ive missed here such as > record size that could impact performance positively (or negatively)? Make sure the host has plenty of RAM (for L2ARC), a good HBA and use the fastest disks you can afford. Mechanical disks (10k/15k SAS) are fine if they’re backed by SSDs. All-flash isn’t something we have the money for, but I imagine (if you get the right ones) you’d have a blast. Try not to have too many storage-intensive zones (KVM or otherwise) on the same host, as you’ll very quickly start losing performance. If you absolutely have to, consider mirror vdevs. We experimented with using SATA disks (in pre-production) and it didn’t end well. We did mess with block sizes briefly, but didn’t see any performance changes that you could consider outside of the margin of error - but as always, YMMV. ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now RSS Feed: https://www.listbox.com/member/archive/rss/184463/25769125-55cfbc00 Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125&id_secret=25769125-7688e9fb Powered by Listbox: http://www.listbox.com
