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SOLVED Swap Cache SSD, then move boot to Old SSD
- Thread starter mpyusko
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- Feb 6, 2014
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Please read the resource linked below, titled "Sync writes, or: Why is my ESXi NFS so slow, and why is iSCSI faster?"
I'm aware you're using XCP and not VMware, but the same principles apply.
www.ixsystems.com
I'm aware you're using XCP and not VMware, but the same principles apply.
Resource - Sync writes, or: Why is my ESXi NFS so slow, and why is iSCSI faster?
This post is not specific to ESXi, however, ESXi users typically experience more trouble with this topic due to the way VMware works. When an application on a client machine wishes to write something to storage, it issues a write request. On a...
www.ixsystems.com
mpyusko
Dabbler
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- Jul 5, 2019
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Ok, so iSCSI is running a hybrid kind of sync mode and NFS isn't. So I should switch iSCSI to sync=always if I want to maintain data integrity and utilize the ZIL/SLOG device? But that will hurt performance overall performance right? The majority of traffic is generally read, not write. After the SAN/NAS has been up and running for a while, very few read requests actually hit the array. In fact, booting or cycling a VM can actually happen straight out of the ARC within seconds. So given the hardware I have... knowing I'm about to nearly double the RAM, double the L2ARC, and drop in a couple x5660 CPUs... What can I do to enhanced write performance while still maintaining data integrity?
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iSCSI still puts your VMs at risk with
sync=standard but it doesn't put the pool itself at risk. If you want full VM safety sync=always is needed for the data integrity; "using an SLOG device" is a way to regain some of the lost performance. If you're willing to risk a bit of data loss to your VMs, and are willing to roll the machines/datastore back to ZFS snapshots or external backups, you can run standard but be sure that you understand the risk you're taking. Having a UPS does mitigate this a fair bit as you're now only subject to internal failures (PSU, HBA, backplane/cabling/etc) versus losing your external power.A faster SLOG device, faster vdevs on the back-end, faster network in-between. Upgrade them based on what's currently bottlenecking you. ;)
mpyusko
Dabbler
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Installed the pair of X5660 CPUs, RAM and larger L2ARC last night. Have to wait on a USB to SATA cable before I can switch from the Flashdrive to the SSD.
Being an R710, I'm limited in my options. The LSI 9210-8i plugs directly into the backplane so I lose two ports. I have L2ARC running in an optical Bay adapter with a SATA-3 add-in card (integrated is SATA-2). I have a USB card so I can hookup the PSu for monitoring, and then I have a PCIe to NVMe adapter which contains the ZIL/SLOG. That ties up all 4 internal slots. Since the PSUs are directly connected to the Mobo, there isn't any way to easily get power for another SSD/Drive. PCIe is limited to 25W so, that leaves USB. So when the adapter cable arrives I'll dd the Flashdrive to the SSD and connect the SSD to the internal USB 2.0 port. For kicks, I tried upgrading to 11.3 last night, but it's still giving me invalid checksum errors.
Being an R710, I'm limited in my options. The LSI 9210-8i plugs directly into the backplane so I lose two ports. I have L2ARC running in an optical Bay adapter with a SATA-3 add-in card (integrated is SATA-2). I have a USB card so I can hookup the PSu for monitoring, and then I have a PCIe to NVMe adapter which contains the ZIL/SLOG. That ties up all 4 internal slots. Since the PSUs are directly connected to the Mobo, there isn't any way to easily get power for another SSD/Drive. PCIe is limited to 25W so, that leaves USB. So when the adapter cable arrives I'll dd the Flashdrive to the SSD and connect the SSD to the internal USB 2.0 port. For kicks, I tried upgrading to 11.3 last night, but it's still giving me invalid checksum errors.
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Just make sure you back up your config. dd'ing and swapping is one method; is there a reason you couldn't have both connected (even if the SSD is external temporarily) and make the boot pool mirrored? Then you can break the mirror later.
The Optane M.2 cards - even the cheap M10 sticks - actually have a higher TBW rating than your 660p. So one of those might be a performance improvement over the current 660p, which could then be repurposed elsewhere. I threw the same CrystalDiskMark test (admittedly not the best) at a test-box here that has a 32GB M.2 Optane SLOG - see the results below:
The Optane M.2 cards - even the cheap M10 sticks - actually have a higher TBW rating than your 660p. So one of those might be a performance improvement over the current 660p, which could then be repurposed elsewhere. I threw the same CrystalDiskMark test (admittedly not the best) at a test-box here that has a 32GB M.2 Optane SLOG - see the results below:
mpyusko
Dabbler
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After all the upgrades (except the boot device (You're right, I'll just mirror then break the mirror. ;) )
iSCSI...
NFS...
I saw a ton of activity on the ZIL/SLOG after setting sync=always.
I also tried to Limit the ARC after upgrading the RAM. (160 GB - 16GB for VMs = 144 GB) Is this correct? or do I need to aslo reserve space for the OS/Kernel?
acrstat.py output....
iSCSI...
NFS...
I saw a ton of activity on the ZIL/SLOG after setting sync=always.
I also tried to Limit the ARC after upgrading the RAM. (160 GB - 16GB for VMs = 144 GB) Is this correct? or do I need to aslo reserve space for the OS/Kernel?
acrstat.py output....
Code:
root@cygnus[~]# arc_summary.py
System Memory:
1.03% 1.61 GiB Active, 1.15% 1.79 GiB Inact
68.17% 106.30 GiB Wired, 0.00% 0 Bytes Cache
29.65% 46.23 GiB Free, -0.00% -188416 Bytes Gap
Real Installed: 160.00 GiB
Real Available: 99.97% 159.95 GiB
Real Managed: 97.48% 155.92 GiB
Logical Total: 160.00 GiB
Logical Used: 69.99% 111.98 GiB
Logical Free: 30.01% 48.02 GiB
Kernel Memory: 1.70 GiB
Data: 97.55% 1.66 GiB
Text: 2.45% 42.62 MiB
Kernel Memory Map: 155.92 GiB
Size: 7.41% 11.56 GiB
Free: 92.59% 144.36 GiB
Page: 1
------------------------------------------------------------------------
ARC Summary: (HEALTHY)
Storage pool Version: 5000
Filesystem Version: 5
Memory Throttle Count: 0
ARC Misc:
Deleted: 3.98m
Mutex Misses: 3.07k
Evict Skips: 3.07k
ARC Size: 64.75% 93.24 GiB
Target Size: (Adaptive) 100.00% 144.00 GiB
Min Size (Hard Limit): 13.45% 19.37 GiB
Max Size (High Water): 7:1 144.00 GiB
ARC Size Breakdown:
Recently Used Cache Size: 49.99% 71.98 GiB
Frequently Used Cache Size: 50.01% 72.02 GiB
ARC Hash Breakdown:
Elements Max: 3.84m
Elements Current: 99.90% 3.83m
Collisions: 1.64m
Chain Max: 5
Chains: 202.91k
Page: 2
------------------------------------------------------------------------
ARC Total accesses: 411.62m
Cache Hit Ratio: 97.55% 401.55m
Cache Miss Ratio: 2.45% 10.07m
Actual Hit Ratio: 93.11% 383.27m
Data Demand Efficiency: 93.36% 35.57m
Data Prefetch Efficiency: 67.08% 10.51m
CACHE HITS BY CACHE LIST:
Anonymously Used: 4.50% 18.07m
Most Recently Used: 5.04% 20.23m
Most Frequently Used: 90.41% 363.04m
Most Recently Used Ghost: 0.04% 151.43k
Most Frequently Used Ghost: 0.01% 55.33k
CACHE HITS BY DATA TYPE:
Demand Data: 8.27% 33.21m
Prefetch Data: 1.76% 7.05m
Demand Metadata: 86.41% 346.98m
Prefetch Metadata: 3.56% 14.30m
CACHE MISSES BY DATA TYPE:
Demand Data: 23.44% 2.36m
Prefetch Data: 34.35% 3.46m
Demand Metadata: 41.80% 4.21m
Prefetch Metadata: 0.42% 42.05k
Page: 3
------------------------------------------------------------------------
L2 ARC Summary: (HEALTHY)
Passed Headroom: 269.57k
Tried Lock Failures: 57.03k
IO In Progress: 1
Low Memory Aborts: 0
Free on Write: 951
Writes While Full: 902
R/W Clashes: 0
Bad Checksums: 0
IO Errors: 0
SPA Mismatch: 110.20m
L2 ARC Size: (Adaptive) 434.40 GiB
Compressed: 65.46% 284.37 GiB
Header Size: 0.03% 151.84 MiB
L2 ARC Breakdown: 9.70m
Hit Ratio: 20.75% 2.01m
Miss Ratio: 79.25% 7.69m
Feeds: 136.63k
L2 ARC Buffer:
Bytes Scanned: 53.94 TiB
Buffer Iterations: 136.63k
List Iterations: 546.48k
NULL List Iterations: 0
L2 ARC Writes:
Writes Sent: 100.00% 62.86k
Page: 4
------------------------------------------------------------------------
DMU Prefetch Efficiency: 58.33m
Hit Ratio: 4.76% 2.78m
Miss Ratio: 95.24% 55.55m
Page: 5
------------------------------------------------------------------------
Page: 6
------------------------------------------------------------------------
ZFS Tunable (sysctl):
kern.maxusers 10572
vm.kmem_size 167419584512
vm.kmem_size_scale 1
vm.kmem_size_min 0
vm.kmem_size_max 1319413950874
vfs.zfs.vol.immediate_write_sz 32768
vfs.zfs.vol.unmap_sync_enabled 0
vfs.zfs.vol.unmap_enabled 1
vfs.zfs.vol.recursive 0
vfs.zfs.vol.mode 2
vfs.zfs.sync_pass_rewrite 2
vfs.zfs.sync_pass_dont_compress 5
vfs.zfs.sync_pass_deferred_free 2
vfs.zfs.zio.dva_throttle_enabled 1
vfs.zfs.zio.exclude_metadata 0
vfs.zfs.zio.use_uma 1
vfs.zfs.zil_slog_bulk 786432
vfs.zfs.cache_flush_disable 0
vfs.zfs.zil_replay_disable 0
vfs.zfs.version.zpl 5
vfs.zfs.version.spa 5000
vfs.zfs.version.acl 1
vfs.zfs.version.ioctl 7
vfs.zfs.debug 0
vfs.zfs.super_owner 0
vfs.zfs.immediate_write_sz 32768
vfs.zfs.standard_sm_blksz 131072
vfs.zfs.dtl_sm_blksz 4096
vfs.zfs.min_auto_ashift 12
vfs.zfs.max_auto_ashift 13
vfs.zfs.vdev.queue_depth_pct 1000
vfs.zfs.vdev.write_gap_limit 4096
vfs.zfs.vdev.read_gap_limit 32768
vfs.zfs.vdev.aggregation_limit_non_rotating131072
vfs.zfs.vdev.aggregation_limit 1048576
vfs.zfs.vdev.trim_max_active 64
vfs.zfs.vdev.trim_min_active 1
vfs.zfs.vdev.scrub_max_active 2
vfs.zfs.vdev.scrub_min_active 1
vfs.zfs.vdev.async_write_max_active 10
vfs.zfs.vdev.async_write_min_active 1
vfs.zfs.vdev.async_read_max_active 3
vfs.zfs.vdev.async_read_min_active 1
vfs.zfs.vdev.sync_write_max_active 10
vfs.zfs.vdev.sync_write_min_active 10
vfs.zfs.vdev.sync_read_max_active 10
vfs.zfs.vdev.sync_read_min_active 10
vfs.zfs.vdev.max_active 1000
vfs.zfs.vdev.async_write_active_max_dirty_percent60
vfs.zfs.vdev.async_write_active_min_dirty_percent30
vfs.zfs.vdev.mirror.non_rotating_seek_inc1
vfs.zfs.vdev.mirror.non_rotating_inc 0
vfs.zfs.vdev.mirror.rotating_seek_offset1048576
vfs.zfs.vdev.mirror.rotating_seek_inc 5
vfs.zfs.vdev.mirror.rotating_inc 0
vfs.zfs.vdev.trim_on_init 1
vfs.zfs.vdev.bio_delete_disable 0
vfs.zfs.vdev.bio_flush_disable 0
vfs.zfs.vdev.cache.bshift 16
vfs.zfs.vdev.cache.size 0
vfs.zfs.vdev.cache.max 16384
vfs.zfs.vdev.default_ms_shift 29
vfs.zfs.vdev.min_ms_count 16
vfs.zfs.vdev.max_ms_count 200
vfs.zfs.vdev.trim_max_pending 10000
vfs.zfs.txg.timeout 5
vfs.zfs.trim.enabled 1
vfs.zfs.trim.max_interval 1
vfs.zfs.trim.timeout 30
vfs.zfs.trim.txg_delay 32
vfs.zfs.spa_min_slop 134217728
vfs.zfs.spa_slop_shift 5
vfs.zfs.spa_asize_inflation 24
vfs.zfs.deadman_enabled 1
vfs.zfs.deadman_checktime_ms 5000
vfs.zfs.deadman_synctime_ms 1000000
vfs.zfs.debug_flags 0
vfs.zfs.debugflags 0
vfs.zfs.recover 0
vfs.zfs.spa_load_verify_data 1
vfs.zfs.spa_load_verify_metadata 1
vfs.zfs.spa_load_verify_maxinflight 10000
vfs.zfs.max_missing_tvds_scan 0
vfs.zfs.max_missing_tvds_cachefile 2
vfs.zfs.max_missing_tvds 0
vfs.zfs.spa_load_print_vdev_tree 0
vfs.zfs.ccw_retry_interval 300
vfs.zfs.check_hostid 1
vfs.zfs.mg_fragmentation_threshold 85
vfs.zfs.mg_noalloc_threshold 0
vfs.zfs.condense_pct 200
vfs.zfs.metaslab_sm_blksz 4096
vfs.zfs.metaslab.bias_enabled 1
vfs.zfs.metaslab.lba_weighting_enabled 1
vfs.zfs.metaslab.fragmentation_factor_enabled1
vfs.zfs.metaslab.preload_enabled 1
vfs.zfs.metaslab.preload_limit 3
vfs.zfs.metaslab.unload_delay 8
vfs.zfs.metaslab.load_pct 50
vfs.zfs.metaslab.min_alloc_size 33554432
vfs.zfs.metaslab.df_free_pct 4
vfs.zfs.metaslab.df_alloc_threshold 131072
vfs.zfs.metaslab.debug_unload 0
vfs.zfs.metaslab.debug_load 0
vfs.zfs.metaslab.fragmentation_threshold70
vfs.zfs.metaslab.force_ganging 16777217
vfs.zfs.free_bpobj_enabled 1
vfs.zfs.free_max_blocks 18446744073709551615
vfs.zfs.zfs_scan_checkpoint_interval 7200
vfs.zfs.zfs_scan_legacy 0
vfs.zfs.no_scrub_prefetch 0
vfs.zfs.no_scrub_io 0
vfs.zfs.resilver_min_time_ms 3000
vfs.zfs.free_min_time_ms 1000
vfs.zfs.scan_min_time_ms 1000
vfs.zfs.scan_idle 50
vfs.zfs.scrub_delay 4
vfs.zfs.resilver_delay 2
vfs.zfs.top_maxinflight 32
vfs.zfs.delay_scale 500000
vfs.zfs.delay_min_dirty_percent 60
vfs.zfs.dirty_data_sync 67108864
vfs.zfs.dirty_data_max_percent 10
vfs.zfs.dirty_data_max_max 4294967296
vfs.zfs.dirty_data_max 4294967296
vfs.zfs.max_recordsize 1048576
vfs.zfs.default_ibs 15
vfs.zfs.default_bs 9
vfs.zfs.zfetch.array_rd_sz 1048576
vfs.zfs.zfetch.max_idistance 67108864
vfs.zfs.zfetch.max_distance 33554432
vfs.zfs.zfetch.min_sec_reap 2
vfs.zfs.zfetch.max_streams 8
vfs.zfs.prefetch_disable 0
vfs.zfs.send_holes_without_birth_time 1
vfs.zfs.mdcomp_disable 0
vfs.zfs.per_txg_dirty_frees_percent 30
vfs.zfs.nopwrite_enabled 1
vfs.zfs.dedup.prefetch 1
vfs.zfs.dbuf_cache_lowater_pct 10
vfs.zfs.dbuf_cache_hiwater_pct 10
vfs.zfs.dbuf_cache_shift 5
vfs.zfs.dbuf_cache_max_bytes 5198307584
vfs.zfs.arc_min_prescient_prefetch_ms 6
vfs.zfs.arc_min_prefetch_ms 1
vfs.zfs.l2c_only_size 0
vfs.zfs.mfu_ghost_data_esize 70523813888
vfs.zfs.mfu_ghost_metadata_esize 0
vfs.zfs.mfu_ghost_size 70523813888
vfs.zfs.mfu_data_esize 40647808512
vfs.zfs.mfu_metadata_esize 216837632
vfs.zfs.mfu_size 41271884800
vfs.zfs.mru_ghost_data_esize 12774014976
vfs.zfs.mru_ghost_metadata_esize 0
vfs.zfs.mru_ghost_size 12774014976
vfs.zfs.mru_data_esize 49226321408
vfs.zfs.mru_metadata_esize 94657024
vfs.zfs.mru_size 58062458880
vfs.zfs.anon_data_esize 0
vfs.zfs.anon_metadata_esize 0
vfs.zfs.anon_size 3687936
vfs.zfs.l2arc_norw 0
vfs.zfs.l2arc_feed_again 1
vfs.zfs.l2arc_noprefetch 0
vfs.zfs.l2arc_feed_min_ms 200
vfs.zfs.l2arc_feed_secs 1
vfs.zfs.l2arc_headroom 2
vfs.zfs.l2arc_write_boost 40000000
vfs.zfs.l2arc_write_max 10000000
vfs.zfs.arc_meta_limit 38654705664
vfs.zfs.arc_free_target 870759
vfs.zfs.arc_kmem_cache_reap_retry_ms 1000
vfs.zfs.compressed_arc_enabled 1
vfs.zfs.arc_grow_retry 60
vfs.zfs.arc_shrink_shift 7
vfs.zfs.arc_average_blocksize 8192
vfs.zfs.arc_no_grow_shift 5
vfs.zfs.arc_min 20793230336
vfs.zfs.arc_max 154618822656
vfs.zfs.abd_chunk_size 4096
Page: 7
------------------------------------------------------------------------
root@cygnus[~]#
mpyusko
Dabbler
- Joined
- Jul 5, 2019
- Messages
- 49
Interestingly enough, the M10 seems significantly slower in Write IOPS than the 660p/665p (There are very minor differences between the two with the major on being the 665p increases TBW from 200 to 300) so wouldn't the 660p/665p be the better choice?
Intel product specifications
Intel® product specifications, features and compatibility quick reference guide and code name decoder. Compare products including processors, desktop boards, server products and networking products.
Cutrently...
Code:
ada0 TBW: 1.41773 TB (L2ARC) da4 TBW: 13.4886 TB (WD Red NAS) da5 TBW: 13.4997 TB (WD Red NAS) nvme0 TBW: [28.3TB] (ZIL/SLOG)
mpyusko
Dabbler
- Joined
- Jul 5, 2019
- Messages
- 49
(See Post)
www.ixsystems.com
SOLVED - checksum fail while installing FreeNAS 11.3
I can feel your frustration mistermanko. I have experienced about the same. I had my freenas running since 9.3 and it has been updated to 9.10 (cant remember exact versions). Going to 11.x version started a lot of problems just like yours. I tried usb2 kingstons that i have used earlier, tried...
www.ixsystems.com
mpyusko
Dabbler
- Joined
- Jul 5, 2019
- Messages
- 49
So I swapped out my 500 GB Samsung 860 EVO and replaced it with the 1 TB Intel 660p NVMe that I was using for my ZIL/SLOG.
Then I added a NEW 250GB Samsung 970 EVO Plus for my ZIL/SLOG.
This is taken straight from a Win10 VM running under BHYVE....
This is from a Win10 VM running under XCP-ng.... (iSCSI)
Same VM only with an NFS Volume....
With no other changes made to the environment, it seems like my RND4KQ1T1 and RND4KQ32T16 Write has gone down significantly.... around half.
What the H???? With the upgrade in hardware, I would expect to see gains, not losses.
arc_summary.py...
Then I added a NEW 250GB Samsung 970 EVO Plus for my ZIL/SLOG.
This is taken straight from a Win10 VM running under BHYVE....
This is from a Win10 VM running under XCP-ng.... (iSCSI)
Same VM only with an NFS Volume....
With no other changes made to the environment, it seems like my RND4KQ1T1 and RND4KQ32T16 Write has gone down significantly.... around half.
What the H???? With the upgrade in hardware, I would expect to see gains, not losses.
Code:
root@cygnus[~]# smartctl -i /dev/nvme1 smartctl 7.0 2018-12-30 r4883 [FreeBSD 11.3-RELEASE-p9 amd64] (local build) Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org === START OF INFORMATION SECTION === Model Number: INTEL SSDPEKNW010T8 Serial Number: PHNH904100TT1P0B Firmware Version: 002C PCI Vendor/Subsystem ID: 0x8086 IEEE OUI Identifier: 0x5cd2e4 Controller ID: 1 Number of Namespaces: 1 Namespace 1 Size/Capacity: 1,024,209,543,168 [1.02 TB] Namespace 1 Formatted LBA Size: 512 Local Time is: Fri Jul 17 13:12:34 2020 EDT root@cygnus[~]# smartctl -i /dev/nvme0 smartctl 7.0 2018-12-30 r4883 [FreeBSD 11.3-RELEASE-p9 amd64] (local build) Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org === START OF INFORMATION SECTION === Model Number: Samsung SSD 970 EVO Plus 250GB Serial Number: S59BNZFN503665L Firmware Version: 2B2QEXM7 PCI Vendor/Subsystem ID: 0x144d IEEE OUI Identifier: 0x002538 Total NVM Capacity: 250,059,350,016 [250 GB] Unallocated NVM Capacity: 0 Controller ID: 4 Number of Namespaces: 1 Namespace 1 Size/Capacity: 250,059,350,016 [250 GB] Namespace 1 Utilization: 223,158,272 [223 MB] Namespace 1 Formatted LBA Size: 512 Namespace 1 IEEE EUI-64: 002538 55019d4a72 Local Time is: Fri Jul 17 13:12:52 2020 EDT da4 TBW: 15.8475 TB (WD Red NAS) da5 TBW: 15.8538 TB (WD Red NAS) nvme0 TBW: [227GB] (ZIL/SLOG) nvme1 TBW: [33.0TB] (L2ARC)
arc_summary.py...
Code:
root@cygnus[~]# arc_summary.py
System Memory:
1.20% 1.87 GiB Active, 0.91% 1.41 GiB Inact
89.28% 139.20 GiB Wired, 0.00% 0 Bytes Cache
3.61% 5.63 GiB Free, 5.00% 7.80 GiB Gap
Real Installed: 160.00 GiB
Real Available: 99.97% 159.94 GiB
Real Managed: 97.48% 155.92 GiB
Logical Total: 160.00 GiB
Logical Used: 95.60% 152.95 GiB
Logical Free: 4.40% 7.05 GiB
Kernel Memory: 1.82 GiB
Data: 97.54% 1.78 GiB
Text: 2.46% 45.94 MiB
Kernel Memory Map: 155.92 GiB
Size: 5.51% 8.60 GiB
Free: 94.49% 147.32 GiB
Page: 1
------------------------------------------------------------------------
ARC Summary: (HEALTHY)
Storage pool Version: 5000
Filesystem Version: 5
Memory Throttle Count: 0
ARC Misc:
Deleted: 1.57m
Mutex Misses: 1.18k
Evict Skips: 1.18k
ARC Size: 99.99% 127.94 GiB
Target Size: (Adaptive) 100.00% 127.95 GiB
Min Size (Hard Limit): 15.13% 19.36 GiB
Max Size (High Water): 6:1 127.95 GiB
ARC Size Breakdown:
Recently Used Cache Size: 63.81% 81.64 GiB
Frequently Used Cache Size: 36.19% 46.31 GiB
ARC Hash Breakdown:
Elements Max: 4.45m
Elements Current: 99.95% 4.45m
Collisions: 978.82k
Chain Max: 5
Chains: 270.34k
Page: 2
------------------------------------------------------------------------
ARC Total accesses: 97.58m
Cache Hit Ratio: 95.54% 93.23m
Cache Miss Ratio: 4.46% 4.35m
Actual Hit Ratio: 92.03% 89.80m
Data Demand Efficiency: 95.44% 32.68m
Data Prefetch Efficiency: 58.34% 6.38m
CACHE HITS BY CACHE LIST:
Anonymously Used: 3.49% 3.26m
Most Recently Used: 11.94% 11.13m
Most Frequently Used: 84.38% 78.67m
Most Recently Used Ghost: 0.10% 91.08k
Most Frequently Used Ghost: 0.09% 82.49k
CACHE HITS BY DATA TYPE:
Demand Data: 33.46% 31.19m
Prefetch Data: 3.99% 3.72m
Demand Metadata: 62.50% 58.27m
Prefetch Metadata: 0.05% 50.34k
CACHE MISSES BY DATA TYPE:
Demand Data: 34.25% 1.49m
Prefetch Data: 61.07% 2.66m
Demand Metadata: 4.33% 188.31k
Prefetch Metadata: 0.35% 15.42k
Page: 3
------------------------------------------------------------------------
L2 ARC Summary: (HEALTHY)
Passed Headroom: 101.64k
Tried Lock Failures: 57.03k
IO In Progress: 0
Low Memory Aborts: 0
Free on Write: 79
Writes While Full: 4.67k
R/W Clashes: 0
Bad Checksums: 0
IO Errors: 0
SPA Mismatch: 5.65m
L2 ARC Size: (Adaptive) 263.31 GiB
Compressed: 74.06% 195.01 GiB
Header Size: 0.05% 124.43 MiB
L2 ARC Breakdown: 4.30m
Hit Ratio: 5.52% 237.43k
Miss Ratio: 94.48% 4.06m
Feeds: 55.96k
L2 ARC Buffer:
Bytes Scanned: 9.89 TiB
Buffer Iterations: 55.96k
List Iterations: 220.88k
NULL List Iterations: 685
L2 ARC Writes:
Writes Sent: 100.00% 31.57k
Page: 4
------------------------------------------------------------------------
DMU Prefetch Efficiency: 18.73m
Hit Ratio: 9.66% 1.81m
Miss Ratio: 90.34% 16.92m
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ZFS Tunable (sysctl):
kern.maxusers 10572
vm.kmem_size 167415398400
vm.kmem_size_scale 1
vm.kmem_size_min 0
vm.kmem_size_max 1319413950874
vfs.zfs.vol.immediate_write_sz 32768
vfs.zfs.vol.unmap_sync_enabled 0
vfs.zfs.vol.unmap_enabled 1
vfs.zfs.vol.recursive 0
vfs.zfs.vol.mode 2
vfs.zfs.sync_pass_rewrite 2
vfs.zfs.sync_pass_dont_compress 5
vfs.zfs.sync_pass_deferred_free 2
vfs.zfs.zio.dva_throttle_enabled 1
vfs.zfs.zio.exclude_metadata 0
vfs.zfs.zio.use_uma 1
vfs.zfs.zio.taskq_batch_pct 75
vfs.zfs.zil_maxblocksize 131072
vfs.zfs.zil_slog_bulk 786432
vfs.zfs.zil_nocacheflush 0
vfs.zfs.zil_replay_disable 0
vfs.zfs.version.zpl 5
vfs.zfs.version.spa 5000
vfs.zfs.version.acl 1
vfs.zfs.version.ioctl 7
vfs.zfs.debug 0
vfs.zfs.super_owner 0
vfs.zfs.immediate_write_sz 32768
vfs.zfs.cache_flush_disable 0
vfs.zfs.standard_sm_blksz 131072
vfs.zfs.dtl_sm_blksz 4096
vfs.zfs.min_auto_ashift 12
vfs.zfs.max_auto_ashift 13
vfs.zfs.vdev.def_queue_depth 32
vfs.zfs.vdev.queue_depth_pct 1000
vfs.zfs.vdev.write_gap_limit 4096
vfs.zfs.vdev.read_gap_limit 32768
vfs.zfs.vdev.aggregation_limit_non_rotating131072
vfs.zfs.vdev.aggregation_limit 1048576
vfs.zfs.vdev.initializing_max_active 1
vfs.zfs.vdev.initializing_min_active 1
vfs.zfs.vdev.removal_max_active 2
vfs.zfs.vdev.removal_min_active 1
vfs.zfs.vdev.trim_max_active 64
vfs.zfs.vdev.trim_min_active 1
vfs.zfs.vdev.scrub_max_active 2
vfs.zfs.vdev.scrub_min_active 1
vfs.zfs.vdev.async_write_max_active 10
vfs.zfs.vdev.async_write_min_active 1
vfs.zfs.vdev.async_read_max_active 3
vfs.zfs.vdev.async_read_min_active 1
vfs.zfs.vdev.sync_write_max_active 10
vfs.zfs.vdev.sync_write_min_active 10
vfs.zfs.vdev.sync_read_max_active 10
vfs.zfs.vdev.sync_read_min_active 10
vfs.zfs.vdev.max_active 1000
vfs.zfs.vdev.async_write_active_max_dirty_percent60
vfs.zfs.vdev.async_write_active_min_dirty_percent30
vfs.zfs.vdev.mirror.non_rotating_seek_inc1
vfs.zfs.vdev.mirror.non_rotating_inc 0
vfs.zfs.vdev.mirror.rotating_seek_offset1048576
vfs.zfs.vdev.mirror.rotating_seek_inc 5
vfs.zfs.vdev.mirror.rotating_inc 0
vfs.zfs.vdev.trim_on_init 1
vfs.zfs.vdev.bio_delete_disable 0
vfs.zfs.vdev.bio_flush_disable 0
vfs.zfs.vdev.cache.bshift 16
vfs.zfs.vdev.cache.size 0
vfs.zfs.vdev.cache.max 16384
vfs.zfs.vdev.validate_skip 0
vfs.zfs.vdev.max_ms_shift 38
vfs.zfs.vdev.default_ms_shift 29
vfs.zfs.vdev.max_ms_count_limit 131072
vfs.zfs.vdev.min_ms_count 16
vfs.zfs.vdev.max_ms_count 200
vfs.zfs.vdev.trim_max_pending 10000
vfs.zfs.txg.timeout 5
vfs.zfs.trim.enabled 1
vfs.zfs.trim.max_interval 1
vfs.zfs.trim.timeout 30
vfs.zfs.trim.txg_delay 32
vfs.zfs.space_map_ibs 14
vfs.zfs.spa_allocators 4
vfs.zfs.spa_min_slop 134217728
vfs.zfs.spa_slop_shift 5
vfs.zfs.spa_asize_inflation 24
vfs.zfs.deadman_enabled 1
vfs.zfs.deadman_checktime_ms 60000
vfs.zfs.deadman_synctime_ms 600000
vfs.zfs.debug_flags 0
vfs.zfs.debugflags 0
vfs.zfs.recover 0
vfs.zfs.spa_load_verify_data 1
vfs.zfs.spa_load_verify_metadata 1
vfs.zfs.spa_load_verify_maxinflight 10000
vfs.zfs.max_missing_tvds_scan 0
vfs.zfs.max_missing_tvds_cachefile 2
vfs.zfs.max_missing_tvds 0
vfs.zfs.spa_load_print_vdev_tree 0
vfs.zfs.ccw_retry_interval 300
vfs.zfs.check_hostid 1
vfs.zfs.mg_fragmentation_threshold 85
vfs.zfs.mg_noalloc_threshold 0
vfs.zfs.condense_pct 200
vfs.zfs.metaslab_sm_blksz 4096
vfs.zfs.metaslab.bias_enabled 1
vfs.zfs.metaslab.lba_weighting_enabled 1
vfs.zfs.metaslab.fragmentation_factor_enabled1
vfs.zfs.metaslab.preload_enabled 1
vfs.zfs.metaslab.preload_limit 3
vfs.zfs.metaslab.unload_delay 8
vfs.zfs.metaslab.load_pct 50
vfs.zfs.metaslab.min_alloc_size 33554432
vfs.zfs.metaslab.df_free_pct 4
vfs.zfs.metaslab.df_alloc_threshold 131072
vfs.zfs.metaslab.debug_unload 0
vfs.zfs.metaslab.debug_load 0
vfs.zfs.metaslab.fragmentation_threshold70
vfs.zfs.metaslab.force_ganging 16777217
vfs.zfs.free_bpobj_enabled 1
vfs.zfs.free_max_blocks 18446744073709551615
vfs.zfs.zfs_scan_checkpoint_interval 7200
vfs.zfs.zfs_scan_legacy 0
vfs.zfs.no_scrub_prefetch 0
vfs.zfs.no_scrub_io 0
vfs.zfs.resilver_min_time_ms 3000
vfs.zfs.free_min_time_ms 1000
vfs.zfs.scan_min_time_ms 1000
vfs.zfs.scan_idle 50
vfs.zfs.scrub_delay 4
vfs.zfs.resilver_delay 2
vfs.zfs.top_maxinflight 32
vfs.zfs.delay_scale 500000
vfs.zfs.delay_min_dirty_percent 60
vfs.zfs.dirty_data_sync_pct 20
vfs.zfs.dirty_data_max_percent 10
vfs.zfs.dirty_data_max_max 4294967296
vfs.zfs.dirty_data_max 4294967296
vfs.zfs.max_recordsize 1048576
vfs.zfs.default_ibs 15
vfs.zfs.default_bs 9
vfs.zfs.zfetch.array_rd_sz 1048576
vfs.zfs.zfetch.max_idistance 67108864
vfs.zfs.zfetch.max_distance 33554432
vfs.zfs.zfetch.min_sec_reap 2
vfs.zfs.zfetch.max_streams 8
vfs.zfs.prefetch_disable 0
vfs.zfs.send_holes_without_birth_time 1
vfs.zfs.mdcomp_disable 0
vfs.zfs.per_txg_dirty_frees_percent 30
vfs.zfs.nopwrite_enabled 1
vfs.zfs.dedup.prefetch 1
vfs.zfs.dbuf_cache_lowater_pct 10
vfs.zfs.dbuf_cache_hiwater_pct 10
vfs.zfs.dbuf_metadata_cache_overflow 0
vfs.zfs.dbuf_metadata_cache_shift 6
vfs.zfs.dbuf_cache_shift 5
vfs.zfs.dbuf_metadata_cache_max_bytes 2599088384
vfs.zfs.dbuf_cache_max_bytes 5198176768
vfs.zfs.arc_min_prescient_prefetch_ms 6
vfs.zfs.arc_min_prefetch_ms 1
vfs.zfs.l2c_only_size 0
vfs.zfs.mfu_ghost_data_esize 85239063552
vfs.zfs.mfu_ghost_metadata_esize 0
vfs.zfs.mfu_ghost_size 85239063552
vfs.zfs.mfu_data_esize 48222936576
vfs.zfs.mfu_metadata_esize 187322880
vfs.zfs.mfu_size 49436049920
vfs.zfs.mru_ghost_data_esize 51167708160
vfs.zfs.mru_ghost_metadata_esize 0
vfs.zfs.mru_ghost_size 51167708160
vfs.zfs.mru_data_esize 79471159808
vfs.zfs.mru_metadata_esize 66280960
vfs.zfs.mru_size 87094208000
vfs.zfs.anon_data_esize 0
vfs.zfs.anon_metadata_esize 0
vfs.zfs.anon_size 1977856
vfs.zfs.l2arc_norw 0
vfs.zfs.l2arc_feed_again 1
vfs.zfs.l2arc_noprefetch 0
vfs.zfs.l2arc_feed_min_ms 200
vfs.zfs.l2arc_feed_secs 1
vfs.zfs.l2arc_headroom 2
vfs.zfs.l2arc_write_boost 40000000
vfs.zfs.l2arc_write_max 10000000
vfs.zfs.arc_meta_limit 34346532704
vfs.zfs.arc_free_target 870737
vfs.zfs.arc_kmem_cache_reap_retry_ms 1000
vfs.zfs.compressed_arc_enabled 1
vfs.zfs.arc_grow_retry 60
vfs.zfs.arc_shrink_shift 7
vfs.zfs.arc_average_blocksize 8192
vfs.zfs.arc_no_grow_shift 5
vfs.zfs.arc_min 20792707072
vfs.zfs.arc_max 137386130816
vfs.zfs.abd_chunk_size 4096
vfs.zfs.abd_scatter_enabled 1
Page: 7
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root@cygnus[~]#
root@cygnus[~]# arcstat.py -f arcsz,c,l2asize,l2size
arcsz c l2asize l2size
127G 127G 195G 263G
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As mentioned before, what makes an SSD a good SLOG device isn't necessarily what you expect. Neither the 660p or the 970 EVO were designed to deliver low latency writes with a cache flush.
mpyusko
Dabbler
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RND4KQ1T1
Also, I ran these two benchmarks simultaneously, from two different hypervisors to the same iSCSI SR as above. (Yes, it's a 2x GigE Lagg) They were both competing for the same resources. at the same time....
If you notice, the Read side had no measurable impact. However the write side was definitely impacted being split between the two hypervisors. The exception is the RND4KQ1T1 which appears to only taken a ~10% hit.
I guess what confuses me is the 970 EVO Plus is a much faster drive. so to have the performance halved, and not even marginally increased, seems a bit odd.
Also, I ran these two benchmarks simultaneously, from two different hypervisors to the same iSCSI SR as above. (Yes, it's a 2x GigE Lagg) They were both competing for the same resources. at the same time....
If you notice, the Read side had no measurable impact. However the write side was definitely impacted being split between the two hypervisors. The exception is the RND4KQ1T1 which appears to only taken a ~10% hit.
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But the EVO is not a "faster drive" if the performance metric in question is "fast sync writes" - which is what an SLOG workload will cause.
Quite simply, for SLOG purposes, it wasn't an upgrade.
mpyusko
Dabbler
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- Joined
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Definitely an upgrade over "not having one at all" but the 660p was doing a better job of it.
I really need to remake the "SLOG thread" with some more recent information, but I would suggest trying to pick up a 16G or 32G Optane card and installing that for an inexpensive M.2 based solution. If you have a full PCIe slot available (or can make one free) then consider a P3700 or Optane 900p. If money is no object, P4800X. If you've got the thermal space, consider a used Radian RMS-200 as well.
mpyusko
Dabbler
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In the interest of filling out the performance Stats:
I upgraded the ZIL/SLOG to a 64 GB M.10 Optane. I initially had a 32GB in there, but I could only saturate 2 NICs with Sync writes. Once I got all 4 NICs configured with iSCSI Multipath, the bottleneck became grossly apparent.
(4) Multipath iSCSI without ZIL/SLOG
(4) Multpath iSCSI with 32 GB m.10 Optane as ZIL/SLOG:
(4) Multipath iSCSI with 64 GB m.10 Optane as ZIL/SLOG:
Based on the stats from Intel, the 64 GB Optane should be able to handle 5 links saturated (writes).
My R710 is pretty well maxed out as far as what I can do to it.
I upgraded the ZIL/SLOG to a 64 GB M.10 Optane. I initially had a 32GB in there, but I could only saturate 2 NICs with Sync writes. Once I got all 4 NICs configured with iSCSI Multipath, the bottleneck became grossly apparent.
(4) Multipath iSCSI without ZIL/SLOG
(4) Multpath iSCSI with 32 GB m.10 Optane as ZIL/SLOG:
(4) Multipath iSCSI with 64 GB m.10 Optane as ZIL/SLOG:
Based on the stats from Intel, the 64 GB Optane should be able to handle 5 links saturated (writes).
My R710 is pretty well maxed out as far as what I can do to it.
If I increase the RAM, it will drop from 1333 to 1066.
I could upgrade the CPUs, but would going from dual X5660 to Dual X5690 really be worth it?
I can increase the mechanical drives to whatever SATA/SAS which may have performance benefits.
I could upgrade the 660p L2ARC, but the gains would be marginal.
The quad NICs are fully utilized (can't add more)*
The internal PCIe slots are fully utilized (LSI SAS-9211-8i, PCIe/NVME L2ARC, PCIe/NVME SLOG, PCIe/SATA3 Boot/OS)
So at this point I'm just going to let it sit and do it's thing. I have about 2 more years before I'll preemtively upgrade the mechanical disks. That should be interesting. This SAN serves iSCSI to VMs along with SMB and NFS shares. The dependents are 3 hypervisors and 6 workstations.
Last edited:
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- Feb 6, 2014
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Generally speaking, extra RAM (quantity) far outweighs the drop in speed. Consider that 1066MHz or "PC3-8500" RAM is still capable of 8500MB/s of bandwidth. I don't think that will be a bottleneck for you. ;)
Given that you only have 3 hypervisors, have you tuned the round-robin policies to switch paths at a lower number of I/Os? You can probably get the low-queue-depth numbers up a little higher.
mpyusko
Dabbler
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Honestly, no (How?). It was driving me nuts getting iSCSI to work properly in the first place. I had multipathing enabled, but couldn't get both paths active. I had a friend login and I'm not 100% sure what the fix was, but I think he said it had something to do with being a FeeNAS box that upgraded to TrueNAS and XCP-ng was looking for FreeNAS but the SAN was serving TrueNAS. He had to update the .conf on the hypervisors to say TrueNAS and restart the links to get multipathing to work. I have not done any tuning. Once I had 2 paths active, I was able to get all 4 working. 2 are dedicated to iSCSI only, 1 NIC is iSCSI/NFS/Internet, and the other NIC is iSCSI/SMB/Management. My thought is iSCSI will always have at least 250 MB/s but can reach 500 MB/s when traffic on the other NICs is light.
I wish I could get the multipathing performance of of NFS and SMB that I can out of iSCSI.
I wish I could get the multipathing performance of of NFS and SMB that I can out of iSCSI.
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My mistake - I forgot that you were using XCP-ng instead of VMware for the hypervisor. I'm not sure how (or if it's possible) to adjust the pathing from anything other than the default "round robin" with whatever internal metric the underlying OS is using for cycling on that.
Re: the enabling it, yes, the switch from FreeNAS to TrueNAS changed the string in the SCSI device ID, so if there were claim rules for "allow MPIO on vendor FreeNAS" then they wouldn't have applied on TrueNAS. Just be careful on the sharing traffic because while it might make for good benchmarks, it could result in weird/unpredictable behavior in real-world. If 3/4 links are basically unused but the fourth is saturated by SMB/NFS then the round-robin could go Fast-Fast-Fast-Timeout/Very Slow and I'm honestly not sure how the multipath driver would react to that.
Re: the enabling it, yes, the switch from FreeNAS to TrueNAS changed the string in the SCSI device ID, so if there were claim rules for "allow MPIO on vendor FreeNAS" then they wouldn't have applied on TrueNAS. Just be careful on the sharing traffic because while it might make for good benchmarks, it could result in weird/unpredictable behavior in real-world. If 3/4 links are basically unused but the fourth is saturated by SMB/NFS then the round-robin could go Fast-Fast-Fast-Timeout/Very Slow and I'm honestly not sure how the multipath driver would react to that.
mpyusko
Dabbler
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- Jul 5, 2019
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- 49
Well..... I could bind out.....
