Fast clone not working Linux repository with xfs/reflink

[BilboBaggins]

Fast clone is not working on the new linux repository setup with XFS and reflink. XFS Setting is enabled on veeam repo and the linux XFS file system looks good to me.
Case #05252257

sudo xfs_info /dev/sdb

isize=512
sectsz=4096
crc=1
reflink=1
bsize=4096
sunit=0
bsize=4096
bsize=4096
sectsz-4096
extsz=4096

[Mildur]

Hi Douglas

Can you tell me a little bit more, what makes you think, that FastClone is not working? You can check the backup session logs in the console to check if FastClone was used in a synthetic full backup. I don‘t have access to the support cases, but maybe I can help.

Can I ask, how job is configured? Are you using synthetic or active full? Active Full will not leverage FastClone.
Is it possible, that you have copied existing backup chains to the xfs repo? If yes, then you must run an active full first or a backup file compact operation.

[jeremybsmith]

I am using the fast clone feature on a Linux repository using XFS. You can verify that the repository has that setting enabled within Veeam, check the backup logs, AND you can also check individual files on the repository side to see whether they have been using the reflink functionality. See the xfs_bmap command for details, but here's an example:

When reflink has NOT been used to generate a file, you will see that the file only has a single extent:

Code: Select all

xfs_bmap -e -l -p -v -v -v  test.txt

test.txt:
 EXT: FILE-OFFSET      BLOCK-RANGE      AG AG-OFFSET        TOTAL FLAGS
   0: [0..7]:          942584..942591    0 (942584..942591)     8 001010
 FLAG Values:
    0100000 Shared extent
    0010000 Unwritten preallocated extent
    0001000 Doesn't begin on stripe unit
    0000100 Doesn't end   on stripe unit
    0000010 Doesn't begin on stripe width
    0000001 Doesn't end   on stripe width

But when a file is using reflinks, you will see many more extents:

Code: Select all

xfs_bmap -e -l -p -v -v -v  'test-win2k19 - localhostD2020-09-23T181026_D8B2.vbk'

test-win2k19 - localhostD2020-09-27T010554_1F01.vbk:                                	 
 EXT: FILE-OFFSET       	BLOCK-RANGE        	AG AG-OFFSET          	TOTAL FLAGS
   0: [0..7]:           	9395239328..9395239335  7 (160..167)                8 001111
   1: [8..34887]:       	9427270912..9427305791  7 (32031744..32066623)  34880 000101
   2: [34888..38471]:   	9427205512..9427209095  7 (31966344..31969927)	 3584 001111
   3: [38472..38799]:   	9428217152..9428217479  7 (32977984..32978311) 	  328 101111
   4: [38800..38863]:   	9427209168..9427209231  7 (31970000..31970063)     64 001111
   5: [38864..63151]:   	9428217544..9428241831  7 (32978376..33002663)  24288 101111
   6: [63152..64775]:   	9427209232..9427210855  7 (31970064..31971687)	 1624 001111
   7: [64776..861487]:  	9428243456..9429040167  7 (33004288..33800999) 796712 100101
   8: [861488..861767]: 	9427210856..9427211135  7 (31971688..31971967)    280 001111
   9: [861768..862055]: 	9429040448..9429040735  7 (33801280..33801567)    288 101111
  10: [862056..862175]: 	9427211136..9427211255  7 (31971968..31972087)    120 001111
  11: [862176..867311]: 	9429040856..9429045991  7 (33801688..33806823)	 5136 101111
  12: [867312..868151]: 	9427211256..9427212095  7 (31972088..31972927)    840 001111
  13: [868152..869711]: 	9429046832..9429048391  7 (33807664..33809223)	 1560 101111

... (some output omitted for brevity) ...

 744: [27882584..27892743]: 9458141056..9458151215  7 (62901888..62912047)    10160 001111
 745: [27892744..27895663]: 9455933168..9455936087  7 (60694000..60696919)     2920 101111
 746: [27895664..27902015]: 9458151216..9458157567  7 (62912048..62918399)     6352 001010
 747: [27902016..28057983]: 9455943376..9456099343  7 (60704208..60860175)   155968 101111
 748: [28057984..28057991]: 9427209096..9427209103  7 (31969928..31969935)        8 001111
 749: [28057992..28058007]: 9458157640..9458157655  7 (62918472..62918487)       16 001111
 750: [28058008..29303511]: 9456099368..9457344871  7 (60860200..62105703)  1245504 101111
 751: [29303512..29303591]: 9458157824..9458157903  7 (62918656..62918735)       80 000101
 FLAG Values:
	0100000 Shared extent
	0010000 Unwritten preallocated extent
	0001000 Doesn't begin on stripe unit
	0000100 Doesn't end   on stripe unit
	0000010 Doesn't begin on stripe width
	0000001 Doesn't end   on stripe width

Regards,

Jeremy Smith
eSilo