PowerFlex: Errore irreversibile del kernel SDC Linux (allocazione di memoria): kernel: net_sched: errore di allocazione della pagina

SDC è installato su una macchina virtuale Linux, tuttavia il problema potrebbe verificarsi su Linux fisico o su qualsiasi altro sistema operativo con SDC installato.

L SDC si è improvvisamente disconnesso.

Probabilmente, kernel Panic dell SDC Linux.

Errori di I/O dell SDC.

Errori di I/O del file system.

Sintomi

Il file messages sul computer Linux segnala un'analisi dello stack SDC, che include le statistiche di allocazione delle pagine (memoria):

 

Dec 3 10:40:50 backup7 kernel: net_sched: page allocation failure: order:4, mode:0x104020
Dec 3 10:40:50 backup7 kernel: CPU: 3 PID: 1538 Comm: net_sched Tainted: P OE ------------ 3.10.0-693.21.1.el7.x86_64 #1
Dec 3 10:40:50 backup7 kernel: Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/21/2015
Dec 3 10:40:50 backup7 kernel: Call Trace:
Dec 3 10:40:50 backup7 kernel: [<ffffffff816ae7c8>] dump_stack+0x19/0x1b
Dec 3 10:40:50 backup7 kernel: [<ffffffff8118cd10>] warn_alloc_failed+0x110/0x180
Dec 3 10:40:50 backup7 kernel: [<ffffffff816aa774>] __alloc_pages_slowpath+0x6b6/0x724
Dec 3 10:40:50 backup7 kernel: [<ffffffff811912a5>] __alloc_pages_nodemask+0x405/0x420
Dec 3 10:40:50 backup7 kernel: [<ffffffff811d5a38>] alloc_pages_current+0x98/0x110
Dec 3 10:40:50 backup7 kernel: [<ffffffff8118bb0e>] __get_free_pages+0xe/0x40
Dec 3 10:40:50 backup7 kernel: [<ffffffff811e146e>] kmalloc_order_trace+0x2e/0xa0
Dec 3 10:40:50 backup7 kernel: [<ffffffff811e5011>] __kmalloc+0x211/0x230
Dec 3 10:40:50 backup7 kernel: [<ffffffffc0530e3e>] mapClass_AllocAndInitObj+0x3e/0x120 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc0531ca6>] mapClass_UpdateAll+0x306/0x760 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc055d54a>] ? mosMitSchedThrd_CurThrdOurs+0x6a/0xa0 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc053df93>] mapMdm_HandleObjUpdate_CK+0x2b3/0x540 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc053e290>] ? mapMdm_SendUpdateReq_CK+0x70/0xcd0 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc053e686>] mapMdm_SendUpdateReq_CK+0x466/0xcd0 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc0547a46>] ? netSock_DoIO+0xe6/0x630 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc05112f0>] ? netChan_SendReq_CK+0x70/0x800 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc0511432>] netChan_SendReq_CK+0x1b2/0x800 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc051a5fe>] netCon_SendReq_CK+0x17e/0x500 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc05158d7>] ? netRPC_SendDone_CK+0x47/0x6f0 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc05159ad>] netRPC_SendDone_CK+0x11d/0x6f0 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc055d7df>] mosMit_RunWithTLS+0x4f/0x60 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc055f0ba>] mosMitSchedThrd_ThrdEntry+0x1aa/0x510 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc055c490>] ? mosTicks_GetCurrentTick+0x20/0x20 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffffc055c4aa>] mosOsThrd_Entry+0x1a/0x40 [scini]
Dec 3 10:40:50 backup7 kernel: [<ffffffff810b4031>] kthread+0xd1/0xe0
Dec 3 10:40:50 backup7 kernel: [<ffffffff810b3f60>] ? insert_kthread_work+0x40/0x40
Dec 3 10:40:50 backup7 kernel: [<ffffffff816c0577>] ret_from_fork+0x77/0xb0
Dec 3 10:40:50 backup7 kernel: [<ffffffff810b3f60>] ? insert_kthread_work+0x40/0x40
Dec 3 10:40:50 backup7 kernel: Mem-Info:
Dec 3 10:40:50 backup7 kernel: active_anon:540198 inactive_anon:192106 isolated_anon:0#012 active_file:526767 inactive_file:908890 isolated_file:0#012 unevictable:0 dirty:2548 writeback:0 unstable:0#012 slab_reclaimable:113189 slab_unreclaimable:12471#012 mapped:4048 shmem:21154 pagetables:2768 bounce:0#012 free:87384 free_pcp:669 free_cma:0
Dec 3 10:40:50 backup7 kernel: Node 0 DMA free:15900kB min:104kB low:128kB high:156kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15992kB managed:15908kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:8kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
Dec 3 10:40:50 backup7 kernel: lowmem_reserve[]: 0 2814 9821 9821
Dec 3 10:40:50 backup7 kernel: Node 0 DMA32 free:200976kB min:19336kB low:24168kB high:29004kB active_anon:195676kB inactive_anon:266280kB active_file:292588kB inactive_file:1429216kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:3129280kB managed:2884228kB mlocked:0kB dirty:1004kB writeback:0kB mapped:5056kB shmem:26680kB slab_reclaimable:405056kB slab_unreclaimable:19648kB kernel_stack:2464kB pagetables:1864kB unstable:0kB bounce:0kB free_pcp:468kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
Dec 3 10:40:50 backup7 kernel: lowmem_reserve[]: 0 0 7006 7006
Dec 3 10:40:50 backup7 kernel: Node 0 Normal free:132556kB min:48136kB low:60168kB high:72204kB active_anon:1965116kB inactive_anon:502176kB active_file:1814484kB inactive_file:2206340kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:7340032kB managed:7174724kB mlocked:0kB dirty:9200kB writeback:0kB mapped:11168kB shmem:57936kB slab_reclaimable:47700kB slab_unreclaimable:30224kB kernel_stack:4960kB pagetables:9208kB unstable:0kB bounce:0kB free_pcp:2212kB local_pcp:704kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
Dec 3 10:40:50 backup7 kernel: lowmem_reserve[]: 0 0 0 0
Dec 3 10:40:50 backup7 kernel: Node 0 DMA: 1*4kB (U) 1*8kB (U) 1*16kB (U) 0*32kB 2*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (M) 3*4096kB (M) = 15900kB
Dec 3 10:40:50 backup7 kernel: Node 0 DMA32: 5802*4kB (UEM) 3223*8kB (UEM) 9329*16kB (UEM) 85*32kB (UEM) 2*64kB (UM) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 201104kB
Dec 3 10:40:50 backup7 kernel: Node 0 Normal: 29631*4kB (UEM) 1755*8kB (U) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 132564kB
Dec 3 10:40:50 backup7 kernel: Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
Dec 3 10:40:50 backup7 kernel: 1469304 total pagecache pages
Dec 3 10:40:50 backup7 kernel: 12478 pages in swap cache
Dec 3 10:40:50 backup7 kernel: Swap cache stats: add 927451, delete 914973, find 1499563/1552563
Dec 3 10:40:50 backup7 kernel: Free swap = 3295096kB
Dec 3 10:40:50 backup7 kernel: Total swap = 4194300kB
Dec 3 10:40:50 backup7 kernel: ScaleIO R2_5 mapClass_AllocAndInitObj:1212 :Error: Failed to allocate memory 36288.Cannot process MDM response

Contemporaneamente o in un secondo momento (a seconda del carico di lavoro), vengono visualizzati "NO_RESOURCES" errori SDC e/o "IO errors" SDC e/o file system:

File di messaggi:
 

Dec  3 11:23:55 backup7 kernel: ScaleIO R2_5 mapClass_UpdateAll:523 :Error: Object ffff8802aa340000 failed to update in place.status NO_RESOURCES (67)
Dec  3 11:24:45 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:361 :[7567770049] IO-ERROR comb: 0. offsetInComb 0. SizeInLB 0. SDS_ID 0. Comb Gen 0. Head Gen 16da.
Dec  3 11:24:45 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:374 :Vol ID 0x7dfb023900000046. Last fault Status IO_FAULT_NOT_PRI(12).Last error Status NOT_FOUND(3) Reason (failed getting LB-Info) Retry count (0) chan (0)
Dec  3 11:24:45 backup7 kernel: blk_update_request: I/O error, dev scinia, sector 2166028544
Dec  3 11:24:45 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:361 :[7567770056] IO-ERROR comb: 0. offsetInComb 0. SizeInLB 0. SDS_ID 0. Comb Gen 0. Head Gen 16da.
Dec  3 11:24:45 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:374 :Vol ID 0x7dfb023900000046. Last fault Status IO_FAULT_NOT_PRI(12).Last error Status NOT_FOUND(3) Reason (failed getting LB-Info) Retry count (0) chan (0)
Dec  3 11:24:45 backup7 kernel: blk_update_request: I/O error, dev scinia, sector 2166028544
Dec  3 11:24:45 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:361 :[7567770372] IO-ERROR comb: 0. offsetInComb 0. SizeInLB 0. SDS_ID 0. Comb Gen 0. Head Gen 16da.
Dec  3 11:24:45 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:374 :Vol ID 0x7dfb023900000046. Last fault Status IO_FAULT_NOT_PRI(12).Last error Status NOT_FOUND(3) Reason (failed getting LB-Info) Retry count (0) chan (0)
Dec  3 11:24:45 backup7 kernel: blk_update_request: I/O error, dev scinia, sector 2166028552
...
...
Dec  3 11:27:05 backup7 kernel: XFS (dm-2): metadata I/O error: block 0x7dec700 ("xfs_trans_read_buf_map") error 19 numblks 32
Dec  3 11:27:05 backup7 kernel: XFS (dm-2): xfs_imap_to_bp: xfs_trans_read_buf() returned error -19.
Dec  3 11:27:05 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:361 :[7567910448] IO-ERROR comb: 0. offsetInComb 0. SizeInLB 0. SDS_ID 0. Comb Gen 0. Head Gen 16ac.
Dec  3 11:27:05 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:374 :Vol ID 0x7dfb023900000046. Last fault Status IO_FAULT_NOT_PRI(12).Last error Status NOT_FOUND(3) Reason (failed getting LB-Info) Retry count (0) chan (0)
Dec  3 11:27:05 backup7 kernel: blk_update_request: I/O error, dev scinia, sector 132042496
Dec  3 11:27:05 backup7 kernel: XFS (dm-2): metadata I/O error: block 0x7dec700 ("xfs_trans_read_buf_map") error 19 numblks 32
Dec  3 11:27:05 backup7 kernel: XFS (dm-2): xfs_imap_to_bp: xfs_trans_read_buf() returned error -19.
Dec  3 11:27:05 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:361 :[7567910460] IO-ERROR comb: 0. offsetInComb 0. SizeInLB 0. SDS_ID 0. Comb Gen 0. Head Gen 16ac.
Dec  3 11:27:05 backup7 kernel: ScaleIO R2_5 mapVolIO_ReportIOErrorIfNeeded:374 :Vol ID 0x7dfb023900000046. Last fault Status IO_FAULT_NOT_PRI(12).Last error Status NOT_FOUND(3) Reason (failed getting LB-Info) Retry count (0) chan (0)
Dec  3 11:27:05 backup7 kernel: blk_update_request: I/O error, dev scinia, sector 132042496

Impatto

L SDC non funziona.

Scollegamento dell SDC.

Perdita dell'accesso a uno o più volumi.

La memoria contigua dell SDC non era sufficiente.

Frammentazione della memoria e memoria insufficiente disponibile sull host.

Poiché il computer Linux aveva poca memoria disponibile e a causa della frammentazione della memoria, non c'era memoria sufficiente per l SDC.

Per impostazione predefinita, SDC utilizza mandrini di grandi dimensioni per l'allocazione della memoria. In questo caso specifico, SDC ha richiesto 36 K (36.288) di memoria che non possono essere allocati:
 

Dec 3 10:40:50 backup7 kernel: ScaleIO R2_5 mapClass_AllocAndInitObj:1212 :Error: Failed to allocate memory 36288.Cannot process MDM response
 

Dal file dei messaggi: c'erano circa 132 MB di memoria disponibile, tuttavia, non erano disponibili abbastanza blocchi di grandi dimensioni (32k, 64k, ecc.) per l'allocazione di memoria, causando un errore irreversibile del kernel:

Erano disponibili blocchi 29631*4kb più 1755*8k blocchi disponibili = 132MB (132564kb).
 

Dec 3 10:40:50 backup7 kernel: Node 0 Normal: 29631*4kB (UEM) 1755*8kB (U) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 132564kB

Nota: È improbabile che accada a un computer con pochi GB di memoria disponibile.

Nota: Un riavvio dell host cancellerà la frammentazione di memoria temporanea fino alla successiva comparsa del problema.

Dal lato SDC non esiste alcuna soluzione alternativa in quanto il comportamento è in base alla progettazione.

Dal lato host:

1) Aggiungere più memoria e assicurarsi che la memoria disponibile rimanga sufficientemente elevata.

2) In questo caso specifico, i computer SDC Linux sono macchine virtuali. Lo spostamento dell SDC in ESXi risolverebbe il problema in quanto gli host ESXi hanno pochi GB di memoria disponibile.

3) Verificare se l'applicazione/i servizi in esecuzione potrebbero causare o contribuire alla frammentazione della memoria.

Versioni interessate

Qualsiasi versione SIO.

Corretto nella versione

N/D