Sirius7777,   While I am not sure how you accidentally deleted those, I do know you will need to reinstall ONIE, and then afterwards the OS. Normally one shouldn't be going into ONIE to change any of the partitions, as there is no recovery except reinstall and try again.    Let me know if this helps.     
Hi, Please help to resolve this issue. I have tried my best but no luck. I need help from your expertise.  actually in ONIE mode, all the partition under /dev/sda were deleted accidentally. after this switch is not able to enter into any grub or OS. here is output that showing by the switch during POST and after POST.    BIOS (Dell Inc) Boot SelectorS3000 3.24.0.5 (48-port 1G/4-port SFP+ 10G) CPLD JTAG to normal mode... done. POST ConfigurationCPU Signature 406D8CPU FamilyID=6, Model=4D, SteppingId=8, Processor=0Microcode Revision 125Platform ID: 0x10041832PMG_CST_CFG_CTL: 0x40006BBL_CR_CTL3: 0x7E2801FFMisc EN: 0x4000840081Gen PM Con1: 0x1008Therm Status: 0x884A0000POST Control=0xEA010303, Status=0xE6009700 BIOS initializations... CPLD JTAG to normal mode... done. BIOS initializations... CPGC Memtest for Channel 0 .................. PASS ECC enabled: channel 0 DECCCTRL_DUNIT_REG=0x000200F3 POST:RTC Battery OK at last cold bootRTC date Thursday 10/22/2020 16:09:58 POST SPD test ............................... PASS POST Lower DRAM Memory testShort memory cell testPerf cnt (curr,fixed): 0x21790FEBA,0x323568012 POST Lower DRAM Memory test ................. PASSPOST Lower DRAM ECC check ................... PASS Dell DxE configurations...Broadcom Preemphasis...Gen1=0x4, Gen2=0x43done.NPU CDR... reg 0x19: exp=0x191, read=0x181... reg 0x13: exp=0x190, read=0x180... done.SM Bus1 PHY...done DxE POSTPOST PCI test ............................... PASSPOST NVRAM check ............................ PASSPOST overall test results ................... PASS POST exit: 00 97 00 E6 03 03 00 EA         A2                                 Version 2.16.1242. Copyright (C) 2013 American Megatrends, Inc.BIOS Date: 05/22/2015 15:25:58 Ver: 0ACBZ018Press or to enter setup.    after it shows a black screen. now I don't know what to do. can anyone please help me?    
Dell Switch S3048 is not booting into grub/ONIE/OS